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1.  Community-Based Care for the Management of Type 2 Diabetes 
Executive Summary
In June 2008, the Medical Advisory Secretariat began work on the Diabetes Strategy Evidence Project, an evidence-based review of the literature surrounding strategies for successful management and treatment of diabetes. This project came about when the Health System Strategy Division at the Ministry of Health and Long-Term Care subsequently asked the secretariat to provide an evidentiary platform for the Ministry’s newly released Diabetes Strategy.
After an initial review of the strategy and consultation with experts, the secretariat identified five key areas in which evidence was needed. Evidence-based analyses have been prepared for each of these five areas: insulin pumps, behavioural interventions, bariatric surgery, home telemonitoring, and community based care. For each area, an economic analysis was completed where appropriate and is described in a separate report.
To review these titles within the Diabetes Strategy Evidence series, please visit the Medical Advisory Secretariat Web site, http://www.health.gov.on.ca/english/providers/program/mas/mas_about.html,
Diabetes Strategy Evidence Platform: Summary of Evidence-Based Analyses
Continuous Subcutaneous Insulin Infusion Pumps for Type 1 and Type 2 Adult Diabetics: An Evidence-Based Analysis
Behavioural Interventions for Type 2 Diabetes: An Evidence-Based Analysis
Bariatric Surgery for People with Diabetes and Morbid Obesity: An Evidence-Based Summary
Community-Based Care for the Management of Type 2 Diabetes: An Evidence-Based Analysis
Home Telemonitoring for Type 2 Diabetes: An Evidence-Based Analysis
Application of the Ontario Diabetes Economic Model (ODEM) to Determine the Cost-effectiveness and Budget Impact of Selected Type 2 Diabetes Interventions in Ontario
Objective
The objective of this report is to determine the efficacy of specialized multidisciplinary community care for the management of type 2 diabetes compared to usual care.
Clinical Need: Target Population and Condition
Diabetes (i.e. diabetes mellitus) is a highly prevalent chronic metabolic disorder that interferes with the body’s ability to produce or effectively use insulin. The majority (90%) of diabetes patients have type 2 diabetes. (1) Based on the United Kingdom Prospective Diabetes Study (UKPDS), intensive blood glucose and blood pressure control significantly reduce the risk of microvascular and macrovascular complications in type 2 diabetics. While many studies have documented that patients often do not meet the glycemic control targets specified by national and international guidelines, factors associated with glycemic control are less well studied, one of which is the provider(s) of care.
Multidisciplinary approaches to care may be particularly important for diabetes management. According guidelines from the Canadian Diabetes Association (CDA), the diabetes health care team should be multi-and interdisciplinary. Presently in Ontario, the core diabetes health care team consists of at least a family physician and/or diabetes specialist, and diabetes educators (registered nurse and registered dietician).
Increasing the role played by allied health care professionals in diabetes care and their collaboration with physicians may represent a more cost-effective option for diabetes management. Several systematic reviews and meta-analyses have examined multidisciplinary care programs, but these have either been limited to a specific component of multidisciplinary care (e.g. intensified education programs), or were conducted as part of a broader disease management program, of which not all were multidisciplinary in nature. Most reviews also do not clearly define the intervention(s) of interest, making the evaluation of such multidisciplinary community programs challenging.
Evidence-Based Analysis Methods
Research Questions
What is the evidence of efficacy of specialized multidisciplinary community care provided by at least a registered nurse, registered dietician and physician (primary care and/or specialist) for the management of type 2 diabetes compared to usual care? [Henceforth referred to as Model 1]
What is the evidence of efficacy of specialized multidisciplinary community care provided by at least a pharmacist and a primary care physician for the management of type 2 diabetes compared to usual care? [Henceforth referred to as Model 2]
Inclusion Criteria
English language full-reports
Published between January 1, 2000 and September 28, 2008
Randomized controlled trials (RCTs), systematic reviews and meta-analyses
Type 2 diabetic adult population (≥18 years of age)
Total sample size ≥30
Describe specialized multidisciplinary community care defined as ambulatory-based care provided by at least two health care disciplines (of which at least one must be a specialist in diabetes) with integrated communication between the care providers.
Compared to usual care (defined as health care provision by non-specialist(s) in diabetes, such as primary care providers; may include referral to other health care professionals/services as necessary)
≥6 months follow-up
Exclusion Criteria
Studies where discrete results on diabetes cannot be abstracted
Predominantly home-based interventions
Inpatient-based interventions
Outcomes of Interest
The primary outcomes for this review were glycosylated hemoglobin (rHbA1c) levels and systolic blood pressure (SBP).
Search Strategy
A literature search was performed on September 28, 2008 using OVID MEDLINE, MEDLINE In-Process and Other Non-Indexed Citations, EMBASE, the Cumulative Index to Nursing & Allied Health Literature (CINAHL), the Cochrane Library, and the International Agency for Health Technology Assessment (INAHTA) for studies published between January 1, 2000 and September 28, 2008. Abstracts were reviewed by a single reviewer and, for those studies meeting the eligibility criteria, full-text articles were obtained. Reference lists were also examined for any additional relevant studies not identified through the search. Articles with unknown eligibility were reviewed with a second clinical epidemiologist, then a group of epidemiologists until consensus was established. The quality of evidence was assessed as high, moderate, low or very low according to GRADE methodology.
Given the high clinical heterogeneity of the articles that met the inclusion criteria, specific models of specialized multidisciplinary community care were examined based on models of care that are currently being supported in Ontario, models of care that were commonly reported in the literature, as well as suggestions from an Expert Advisory Panel Meeting held on January 21, 2009.
Summary of Findings
The initial search yielded 2,116 unique citations, from which 22 RCTs trials and nine systematic reviews published were identified as meeting the eligibility criteria. Of these, five studies focused on care provided by at least a nurse, dietician, and physician (primary care and/or specialist) model of care (Model 1; see Table ES 1), while three studies focused on care provided by at least a pharmacist and primary care physician (Model 2; see Table ES 2).
Based on moderate quality evidence, specialized multidisciplinary community care Model 2 has demonstrated a statistically and clinically significant reduction in HbA1c of 1.0% compared with usual care. The effects of this model on SBP, however, are uncertain compared with usual care, based on very-low quality evidence. Specialized multidisciplinary community care Model 2 has demonstrated a statistically and clinically significant reduction in both HbA1c of 1.05% (based on high quality evidence) and SBP of 7.13 mm Hg (based on moderate quality evidence) compared to usual care. For both models, the evidence does not suggest a preferred setting of care delivery (i.e., primary care vs. hospital outpatient clinic vs. community clinic).
Summary of Results of Meta-Analyses of the Effects of Multidisciplinary Care Model 1
Mean change from baseline to follow-up between intervention and control groups
Summary of Results of Meta-Analyses of the Effects of Multidisciplinary Care Model 2
Mean change from baseline to follow-up between intervention and control groups
PMCID: PMC3377524  PMID: 23074528
2.  Exploration of transitional life events in individuals with Friedreich ataxia: Implications for genetic counseling 
Abstract
Background
Human development is a process of change, adaptation and growth. Throughout this process, transitional events mark important points in time when one's life course is significantly altered. This study captures transitional life events brought about or altered by Friedreich ataxia, a progressive chronic illness leading to disability, and the impact of these events on an affected individual's life course.
Methods
Forty-two adults with Friedreich ataxia (18-65y) were interviewed regarding their perceptions of transitional life events. Data from the interviews were coded and analyzed thematically using an iterative process.
Results
Identified transitions were either a direct outcome of Friedreich ataxia, or a developmental event altered by having the condition. Specifically, an awareness of symptoms, fear of falling and changes in mobility status were the most salient themes from the experience of living with Friedreich ataxia. Developmental events primarily influenced by the condition were one's relationships and life's work.
Conclusions
Friedreich ataxia increased the complexity and magnitude of transitional events for study participants. Transitional events commonly represented significant loss and presented challenges to self-esteem and identity. Findings from this study help alert professionals of potentially challenging times in patients' lives, which are influenced by chronic illness or disability. Implications for developmental counseling approaches are suggested for genetic counseling.
Background
Human development can be described in terms of key transitional events, or significant times of change. Transitional events initiate shifts in the meaning or direction of life and require the individual to develop skills or utilize coping strategies to adapt to a novel situation [1,2]. A successful transition has been defined as the development of a sense of mastery over the changed event [3].
Transitions can be influenced by a variety of factors including one's stage of development, such as graduation from high school, historical events, including war, and idiosyncratic factors, such as health status [4,5]. Of particular interest in the present study are transitional life events, brought about or altered by progressive chronic illness and disability, and the impact of these events on the lives of affected individuals.
It has been recognized that the clinical characteristics of a chronic illness or disability may alter the course and timing of many developmentally-related transitional events [6]. For example, conditions associated with a shortened lifespan may cause an individual to pursue a career with a shorter course of training [6]. Specific medical manifestations may also promote a lifestyle incongruent with developmental needs [6,7]. For example, an adolescent with a disability may have difficulty achieving autonomy because of his/her physical dependence on others.
In addition to the aforementioned effects of chronic illness and disability on developmentally-related transitional events, a growing body of literature has described disease-related transitional events: those changes that are a direct result of chronic illness and disability. Diagnosis has received attention as being a key disease-related transitional event [8,9]. Studies have also noted other disease transitions related to illness trajectory [10], as the clinical features of the disease may require the individual to make specific adaptations. Disease-related events have also been described in terms of accompanying psychological processes, such as one's awareness of differences brought about by illness [11].
While disease-related events are seemingly significant, the patient's perception of the events is varied. Some events may be perceived as positive experiences for the individual. For example, a diagnosis may end years of uncertainty. Some individuals may perceive these transitional events as insignificant, as they have accommodated to the continual change brought about by a chronic disease [12,13].
The aforementioned impact of disability and chronic illness on transitional events may create psychological stress. Developed by Lazarus and Folkman, the Transitional Model of Stress and Coping describes the process of adaptation to a health condition [14]. This model purports that individuals first appraise a stressor and then utilize a variety of coping strategies in order to meet the stressor's demands [14]. Thus, in the context of chronic illness, the ability of the individual to cope successfully with the stress of a health threat contributes to the process of overall adaptation to the condition.
The process of adaptation can be more complex when the chronic illness or disability is progressive. Each transition brought about or altered by the disability may also represent additional loss, including the loss of future plans, freedom in social life and the ability to participate in hobbies [15]. These losses may be accompanied by grief, uncertainty, and a continual need for adaptation [16,17].
Friedreich ataxia (FRDA) is one example of a progressive disorder, leading to adolescent and adult onset disability. To better understand patients' perceptions of key transitional events and the factors perceived to facilitate progression through these events, individuals with FRDA were interviewed.
FRDA is a rare, progressive, neurodegenerative disorder affecting approximately one in 30,000 people in the United States [18]. It equally affects both men and women. Individuals with FRDA experience progressive muscle weakness and loss of coordination in the arms and legs. For most patients, ataxia leads to motor incapacitation and full-time use of a wheelchair, commonly by the late teens or early twenties. Other complications such as vision and hearing impairment, dysarthria, scoliosis, diabetes mellitus and hypertrophic cardiomyopathy may occur [19,20]. Cardiomyopathy and respiratory difficulties often lead to premature death at an average age of 37 years [21]. Currently, there are no treatments or cures for FRDA. Little is known about the specific psychological or psychosocial effects of the condition.
FRDA is an autosomal recessive condition. The typical molecular basis of Friedreich ataxia is the expansion of a GAA trinucleotide repeat in both copies of the FXN gene [22]. Age of onset usually occurs in late childhood or early adolescence. However, the availability of genetic testing has identified affected individuals with an adult form of the condition. This late-onset form is thought to represent approximately 10-15% of the total FRDA population [23].
Health care providers of individuals with progressive, neurodegenerative disorders can help facilitate their patients' progression through transitional events. Data suggest that improvements should be made in the care of these individuals. Shaw et al. [24] found that individualized care that helps to prepare patients for transition is beneficial. Beisecker et al. [25] found that patients desire not only physical care from their providers, but also emotional and psychosocial support.
Genetic counselors have an important opportunity to help patients with neuromuscular disorders progress through transitional events, as several of these conditions have a genetic etiology. Genetic counselors in pediatric and adult settings often develop long-term relationships with patients, due to follow-up care. This extended relationship is becoming increasingly common as genetic counselors move into various medical sub-specialties, such as neurology, ophthalmology, oncology and cardiology.
The role of the genetic counselor in addressing the psychosocial needs of patients has been advocated, but rarely framed in the context of developmental events [26]. Data suggest that patients may not expect a genetic counselor to address psychosocial needs [27]. In a survey of genetic counseling patients, Wertz [28] found a majority of respondents understood genetic conditions to have a moderate to serious effect on family life and finances, while almost half perceived there to be an effect on the spouse, quality of life, and the relationship between home and work. However, these topics were reportedly not discussed within genetic counseling sessions [27,28]. Overall, there is limited information about the experiences of transitional life events in FRDA, as well as a lack of recommendations for genetic counselors and other health care providers to assist patients through these events.
Our study investigated perceptions of patients with Friedreich ataxia to 1) identify key transitional events and specific needs associated with events; 2) describe perception of factors to facilitate progression through the identified events; and 3) explore the actual or potential role of the health care provider in facilitating adaptation to the identified events. Data were used to make suggestions for developmental genetic counseling approaches in the context of ongoing care of clients with hereditary, progressive, neurodegenerative conditions.
doi:10.1186/1744-9081-6-65
PMCID: PMC2987979  PMID: 20979606
3.  Minimally invasive surgical procedures for the treatment of lumbar disc herniation 
Introduction
In up to 30% of patients undergoing lumbar disc surgery for herniated or protruded discs outcomes are judged unfavourable. Over the last decades this problem has stimulated the development of a number of minimally-invasive operative procedures. The aim is to relieve pressure from compromised nerve roots by mechanically removing, dissolving or evaporating disc material while leaving bony structures and surrounding tissues as intact as possible. In Germany, there is hardly any utilisation data for these new procedures – data files from the statutory health insurances demonstrate that about 5% of all lumbar disc surgeries are performed using minimally-invasive techniques. Their real proportion is thought to be much higher because many procedures are offered by private hospitals and surgeries and are paid by private health insurers or patients themselves. So far no comprehensive assessment comparing efficacy, safety, effectiveness and cost-effectiveness of minimally-invasive lumbar disc surgery to standard procedures (microdiscectomy, open discectomy) which could serve as a basis for coverage decisions, has been published in Germany.
Objective
Against this background the aim of the following assessment is:
Based on published scientific literature assess safety, efficacy and effectiveness of minimally-invasive lumbar disc surgery compared to standard procedures. To identify and critically appraise studies comparing costs and cost-effectiveness of minimally-invasive procedures to that of standard procedures. If necessary identify research and evaluation needs and point out regulative needs within the German health care system. The assessment focusses on procedures that are used in elective lumbar disc surgery as alternative treatment options to microdiscectomy or open discectomy. Chemonucleolysis, percutaneous manual discectomy, automated percutaneous lumbar discectomy, laserdiscectomy and endoscopic procedures accessing the disc by a posterolateral or posterior approach are included.
Methods
In order to assess safety, efficacy and effectiveness of minimally-invasive procedures as well as their economic implications systematic reviews of the literature are performed. A comprehensive search strategy is composed to search 23 electronic databases, among them MEDLINE, EMBASE and the Cochrane Library. Methodological quality of systematic reviews, HTA reports and primary research is assessed using checklists of the German Scientific Working Group for Health Technology Assessment. Quality and transparency of cost analyses are documented using the quality and transparency catalogues of the working group. Study results are summarised in a qualitative manner. Due to the limited number and the low methodological quality of the studies it is not possible to conduct metaanalyses. In addition to the results of controlled trials results of recent case series are introduced and discussed.
Results
The evidence-base to assess safety, efficacy and effectiveness of minimally-invasive lumbar disc surgery procedures is rather limited:
Percutaneous manual discectomy: Six case series (four after 1998)Automated percutaneous lumbar discectomy: Two RCT (one discontinued), twelve case series (one after 1998)Chemonucleolysis: Five RCT, five non-randomised controlled trials, eleven case seriesPercutaneous laserdiscectomy: One non-randomised controlled trial, 13 case series (eight after 1998)Endoscopic procedures: Three RCT, 21 case series (17 after 1998)
There are two economic analyses each retrieved for chemonucleolysis and automated percutaneous discectomy as well as one cost-minimisation analysis comparing costs of an endoscopic procedure to costs for open discectomy.
Among all minimally-invasive procedures chemonucleolysis is the only of which efficacy may be judged on the basis of results from high quality randomised controlled trials (RCT). Study results suggest that the procedure maybe (cost)effectively used as an intermediate therapeutical option between conservative and operative management of small lumbar disc herniations or protrusions causing sciatica. Two RCT comparing transforaminal endoscopic procedures with microdiscectomy in patients with sciatica and small non-sequestered disc herniations show comparable short and medium term overall success rates. Concerning speed of recovery and return to work a trend towards more favourable results for the endoscopic procedures is noted. It is doubtful though, whether these results from the eleven and five years old studies are still valid for the more advanced procedures used today. The only RCT comparing the results of automated percutaneous lumbar discectomy to those of microdiscectomy showed clearly superior results of microdiscectomy. Furthermore, success rates of automated percutaneous lumbar discectomy reported in the RCT (29%) differ extremely from success rates reported in case series (between 56% and 92%).
The literature search retrieves no controlled trials to assess efficacy and/or effectiveness of laser-discectomy, percutaneous manual discectomy or endoscopic procedures using a posterior approach in comparison to the standard procedures. Results from recent case series permit no assessment of efficacy, especially not in comparison to standard procedures. Due to highly selected patients, modi-fications of operative procedures, highly specialised surgical units and poorly standardised outcome assessment results of case series are highly variable, their generalisability is low.
The results of the five economical analyses are, due to conceptual and methodological problems, of no value for decision-making in the context of the German health care system.
Discussion
Aside from low methodological study quality three conceptual problems complicate the interpretation of results.
Continuous further development of technologies leads to a diversity of procedures in use which prohibits generalisation of study results. However, diversity is noted not only for minimally-invasive procedures but also for the standard techniques against which the new developments are to be compared. The second problem refers to the heterogeneity of study populations. For most studies one common inclusion criterion was "persisting sciatica after a course of conservative treatment of variable duration". Differences among study populations are noted concerning results of imaging studies. Even within every group of minimally-invasive procedure, studies define their own in- and exclusion criteria which differ concerning degree of dislocation and sequestration of disc material. There is the non-standardised assessment of outcomes which are performed postoperatively after variable periods of time. Most studies report results in a dichotomous way as success or failure while the classification of a result is performed using a variety of different assessment instruments or procedures. Very often the global subjective judgement of results by patients or surgeons is reported. There are no scientific discussions whether these judgements are generalisable or comparable, especially among studies that are conducted under differing socio-cultural conditions. Taking into account the weak evidence-base for efficacy and effectiveness of minimally-invasive procedures it is not surprising that so far there are no dependable economic analyses.
Conclusions
Conclusions that can be drawn from the results of the present assessment refer in detail to the specified minimally-invasive procedures of lumbar disc surgery but they may also be considered exemplary for other fields where optimisation of results is attempted by technological development and widening of indications (e.g. total hip replacement).
Compared to standard technologies (open discectomy, microdiscectomy) and with the exception of chemonucleolysis, the developmental status of all other minimally-invasive procedures assessed must be termed experimental. To date there is no dependable evidence-base to recommend their use in routine clinical practice. To create such a dependable evidence-base further research in two directions is needed: a) The studies need to include adequate patient populations, use realistic controls (e.g. standard operative procedures or continued conservative care) and use standardised measurements of meaningful outcomes after adequate periods of time. b) Studies that are able to report effectiveness of the procedures under everyday practice conditions and furthermore have the potential to detect rare adverse effects are needed. In Sweden this type of data is yielded by national quality registries. On the one hand their data are used for quality improvement measures and on the other hand they allow comprehensive scientific evaluations. Since the year of 2000 a continuous rise in utilisation of minimally-invasive lumbar disc surgery is observed among statutory health insurers. Examples from other areas of innovative surgical technologies (e.g. robot assisted total hip replacement) indicate that the rise will probably continue - especially because there are no legal barriers to hinder introduction of innovative treatments into routine hospital care. Upon request by payers or providers the "Gemeinsamer Bundesausschuss" may assess a treatments benefit, its necessity and cost-effectiveness as a prerequisite for coverage by the statutory health insurance. In the case of minimally-invasive disc surgery it would be advisable to examine the legal framework for covering procedures only if they are provided under evaluation conditions. While in Germany coverage under evaluation conditions is established practice in ambulatory health care only (“Modellvorhaben") examples from other European countries (Great Britain, Switzerland) demonstrate that it is also feasible for hospital based interventions. In order to assure patient protection and at the same time not hinder the further development of new and promising technologies provision under evaluation conditions could also be realised in the private health care market - although in this sector coverage is not by law linked to benefit, necessity and cost-effectiveness of an intervention.
PMCID: PMC3011322  PMID: 21289928
4.  Clinical Benefits, Costs, and Cost-Effectiveness of Neonatal Intensive Care in Mexico 
PLoS Medicine  2010;7(12):e1000379.
Joshua Salomon and colleagues performed a cost-effectiveness analysis using health and economic outcomes following preterm birth in Mexico and showed that neonatal intensive care provided high value for the money in this setting.
Background
Neonatal intensive care improves survival, but is associated with high costs and disability amongst survivors. Recent health reform in Mexico launched a new subsidized insurance program, necessitating informed choices on the different interventions that might be covered by the program, including neonatal intensive care. The purpose of this study was to estimate the clinical outcomes, costs, and cost-effectiveness of neonatal intensive care in Mexico.
Methods and Findings
A cost-effectiveness analysis was conducted using a decision analytic model of health and economic outcomes following preterm birth. Model parameters governing health outcomes were estimated from Mexican vital registration and hospital discharge databases, supplemented with meta-analyses and systematic reviews from the published literature. Costs were estimated on the basis of data provided by the Ministry of Health in Mexico and World Health Organization price lists, supplemented with published studies from other countries as needed. The model estimated changes in clinical outcomes, life expectancy, disability-free life expectancy, lifetime costs, disability-adjusted life years (DALYs), and incremental cost-effectiveness ratios (ICERs) for neonatal intensive care compared to no intensive care. Uncertainty around the results was characterized using one-way sensitivity analyses and a multivariate probabilistic sensitivity analysis. In the base-case analysis, neonatal intensive care for infants born at 24–26, 27–29, and 30–33 weeks gestational age prolonged life expectancy by 28, 43, and 34 years and averted 9, 15, and 12 DALYs, at incremental costs per infant of US$11,400, US$9,500, and US$3,000, respectively, compared to an alternative of no intensive care. The ICERs of neonatal intensive care at 24–26, 27–29, and 30–33 weeks were US$1,200, US$650, and US$240, per DALY averted, respectively. The findings were robust to variation in parameter values over wide ranges in sensitivity analyses.
Conclusions
Incremental cost-effectiveness ratios for neonatal intensive care imply very high value for money on the basis of conventional benchmarks for cost-effectiveness analysis.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Most pregnancies last about 40 weeks but increasing numbers of babies are being born preterm, before they reach 37 weeks of gestation (the period during which a baby develops in its mother). In developed countries and some middle-income countries such as Mexico, improvements in the care of newborn babies (neonatal intensive care) mean that more preterm babies survive now than in the past. Nevertheless, preterm birth is still a major cause of infant death worldwide that challenges attainment of Target 5 of Millennium Development Goal 4—the reduction of the global under-five mortality rate by two-thirds of the 1990 rate by 2015 (the Millennium Development Goals, which were agreed by world leaders in 2000, aim to reduce world poverty). Furthermore, many preterm babies who survive have long-term health problems and disabilities such as cerebral palsy, deafness, or learning difficulties. The severity of these disabilities and their long-term costs to families and to society depend on the baby's degree of prematurity.
Why Was This Study Done?
Mexico recently reformed its health system in an effort to improve access to care, particularly for the poorest sections of its population, and to improve the quality of its health care. The central component of this health care reform is the System of Social Protection of Health (SSPH). The SSPH contains a family health insurance program—Seguro Popular—that aims to provide the 50 million uninsured people living in Mexico with free access to an explicit set of health care interventions. As with any insurance program, decisions have to be made about which interventions Seguro Poplar should cover. Should neonatal intensive care be covered, for example? Do the benefits of this intervention (increased survival of babies) outweigh the costs of neonatal care and of long-term care for survivors with disabilities? In other words, is neonatal intensive care cost-effective? In this study, the researchers investigate this question by estimating the clinical benefits, costs, and cost-effectiveness of neonatal intensive care in Mexico.
What Did the Researchers Do and Find?
The researchers built a decision analytic model, a mathematical model that combines evidence on the outcomes and costs of alternative treatments to help inform decisions about health care policy. They gathered data about the health outcomes of preterm births in Mexico from registers of births and deaths and from hospital discharge databases, and estimated the costs of neonatal intensive care and long-term care for disabled survivors using data from the Mexican Ministry of Health and the World Health Organization. They then applied their model, which estimates changes in parameters such as life expectancy, lifetime costs, disability-adjusted life years (DALYs; one DALY represents the loss of a year of healthy life), and incremental cost-effectiveness ratios (ICERs; the additional cost expended for each DALY averted) for neonatal intensive care compared to no intensive care, to a group of 2 million infants. Neonatal intensive care for infants born at 24–26, 27–29, and 30–33 weeks gestation prolonged life expectancy by 28, 43, and 34 years and averted 9, 15, and 12 DALYs at incremental costs of US$11,000, US$10,000, and US$3000, respectively, compared to no intensive care. The ICERs of neonatal intensive care for babies born at these times were US$1200, US$700, and US$300 per DALY averted, respectively.
What Do These Findings Mean?
Interventions with ICERs of less than a country's per capita gross domestic product (GDP) are highly cost-effective; those with ICERs of 1–3 times the per capita GDP are potentially cost-effective. Mexico's per capita GDP in 2005 was approximately US$8,200. Thus, neonatal intensive care could provide exceptional value for money in Mexico (and maybe in other middle-income countries), even for very premature babies. The accuracy of these findings inevitably depends on the assumptions used to build the decision analytic model and on the accuracy of the data fed into it, but the findings were little changed by a wide range of alterations that the researchers made to the model. Importantly, however, this cost-effectiveness analysis focuses on health and economic consequences of different intervention choices, and does not capture all aspects of well-being. Decisions regarding neonatal intensive care will need to be based on a full consideration of all relevant factors, including ethical issues, and cost-effectiveness analyses should continue to be updated as new data emerge on health outcomes and costs associated with neonatal intensive care.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1000379.
The March of Dimes, a nonprofit organization for pregnancy and baby health, provides information on preterm birth (in English and Spanish)
The Nemours Foundation, another nonprofit organization for child health, also provides information on premature babies (in English and Spanish)
MedlinePlus provides links to other information on premature babies (in English and Spanish)
The United Nations Childrens Fund (UNICEF) works for children's rights, survival, development and protection around the world; it provides information on Millennium Development Goal 4 and its Childinfo website provides detailed statistics about child survival and health (some information in several languages)
A PLoS Medicine Policy Forum by Núria Homedes and Antonio Ugalde discusses health care reforms in Mexico
doi:10.1371/journal.pmed.1000379
PMCID: PMC3001895  PMID: 21179496
5.  Configuring Balanced Scorecards for Measuring Health System Performance: Evidence from 5 Years' Evaluation in Afghanistan 
PLoS Medicine  2011;8(7):e1001066.
Anbrasi Edward and colleagues report the results of a balanced scorecard performance system used to examine 29 key performance indicators over a 5-year period in Afghanistan, between 2004 and 2008.
Background
In 2004, Afghanistan pioneered a balanced scorecard (BSC) performance system to manage the delivery of primary health care services. This study examines the trends of 29 key performance indicators over a 5-year period between 2004 and 2008.
Methods and Findings
Independent evaluations of performance in six domains were conducted annually through 5,500 patient observations and exit interviews and 1,500 provider interviews in >600 facilities selected by stratified random sampling in each province. Generalized estimating equation (GEE) models were used to assess trends in BSC parameters. There was a progressive improvement in the national median scores scaled from 0–100 between 2004 and 2008 in all six domains: patient and community satisfaction of services (65.3–84.5, p<0.0001); provider satisfaction (65.4–79.2, p<0.01); capacity for service provision (47.4–76.4, p<0.0001); quality of services (40.5–67.4, p<0.0001); and overall vision for pro-poor and pro-female health services (52.0–52.6). The financial domain also showed improvement until 2007 (84.4–95.7, p<0.01), after which user fees were eliminated. By 2008, all provinces achieved the upper benchmark of national median set in 2004.
Conclusions
The BSC has been successfully employed to assess and improve health service capacity and service delivery using performance benchmarking during the 5-year period. However, scorecard reconfigurations are needed to integrate effectiveness and efficiency measures and accommodate changes in health systems policy and strategy architecture to ensure its continued relevance and effectiveness as a comprehensive health system performance measure. The process of BSC design and implementation can serve as a valuable prototype for health policy planners managing performance in similar health care contexts.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Traditionally, the performance of a health system (the complete network of health care agencies, facilities, and providers in a defined geographical region) has been measured in terms of health outcomes: how many people have been treated, how many got better, and how many died. But, nowadays, with increased demand for improved governance and accountability, policy makers are seeking comprehensive performance measures that show in detail how innovations designed to strengthen health systems are affecting service delivery and health outcomes. One such performance measure is the “balanced scorecard,” an integrated management and measurement tool that enables organizations to clarify their vision and strategy and translate them into action. The balanced scorecard—essentially a list of key performance indicators and performance benchmarks in several domains—was originally developed for industry but is now becoming a popular strategic management tool in the health sector. For example, balanced scorecards have been successfully integrated into the Dutch and Italian public health care systems.
Why Was This Study Done?
Little is known about the use of balanced scorecards in the national public health care systems of developing countries but the introduction of performance management into health system reform in fragile states in particular (developing countries where the state fails to perform the fundamental functions necessary to meet its citizens' basic needs and expectations) could help to promote governance and leadership, and facilitate essential policy changes. One fragile state that has introduced the balanced scorecard system for public health care management is Afghanistan, which emerged from decades of conflict in 2002 with some of the world's worst health indicators. To deal with an extremely high burden of disease, the Ministry of Public Health (MOPH) designed a Basic Package of Health Services (BPHS), which is delivered by nongovernmental organizations and MOPH agencies. In 2004, the MOPH introduced the National Health Service Performance Assessment (NHSPA), an annual country-wide assessment of service provision and patient satisfaction and pioneered a balanced scorecard, which uses data collected in the NHSPA, to manage the delivery of primary health care services. In this study, the researchers examine the trends between 2004 and 2008 of the 29 key performance indicators in six domains included in this balanced scorecard, and consider the potential and limitations of the scorecard as a management tool to measure and improve health service delivery in Afghanistan and other similar countries.
What Did the Researchers Do and Find?
Each year of the study, a random sample of 25 facilities (district hospitals and comprehensive and basic health centers) in 28 of Afghanistan's 34 provinces was chosen (one province did not have functional facilities in 2004 and the other five missing provinces were inaccessible because of ongoing conflicts). NHSPA surveyors collected approximately 5,000 patient observations, 5,000 exit interviews with patients or their caregivers, and 1,500 health provider interviews by observing consultations involving five children under 5 years old and five patients over 5 years old in each facility. The researchers then used this information to evaluate the key performance indicators in the balanced scorecard and a statistical method called generalized estimating equation modeling to assess trends in these indicators. They report that there was a progressive improvement in national average scores in all six domains (patients and community satisfaction with services, provider satisfaction, capacity for service provision, quality of services, overall vision for pro-poor and pro-female health services, and financial systems) between 2004 and 2008.
What Do These Findings Mean?
These findings suggest that the balanced scorecard was successfully used to improve health system capacity and service delivery through performance benchmarking over the 5-year study period. Importantly, the use of the balanced scorecard helped to show the effects of investments, facilitate policy change, and create a more evidence-based decision-making culture in Afghanistan's primary health care system. However, the researchers warn that the continuing success of the balanced scorecard in Afghanistan will depend on its ability to accommodate changes in health systems policy. Furthermore, reconfigurations of the scorecard are needed to include measures of the overall effectiveness and efficiency of the health system such as mortality rates. More generally, the researchers conclude that the balanced scorecard offers a promising measure of health system performance that could be used to examine the effectiveness of health care strategies and innovations in other fragile and developing countries.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001066.
A 2010 article entitled An Afghan Success Story: The Balanced Scorecard and Improved Health Services in The Globe, a newsletter produced by the Department of International Health at the John Hopkins Bloomberg School of Public Health, provides a detailed description of the balanced scorecard used in this study
Wikipedia has a page on health systems and on balanced scorecards (note that Wikipedia is a free online encyclopedia that anyone can edit; available in several languages)
The World Health Organization country profile of Afghanistan provides information on the country's health system and burden of disease (in several languages)
doi:10.1371/journal.pmed.1001066
PMCID: PMC3144209  PMID: 21814499
6.  Epilepsy Care in Ontario: An Economic Analysis of Increasing Access to Epilepsy Surgery 
Background
In August 2011 a proposed epilepsy care model was presented to the Ontario Health Technology Advisory Committee (OHTAC) by an Expert Panel on a Provincial Strategy for Epilepsy Care in Ontario. The Expert Panel recommended leveraging existing infrastructure in the province to provide enhanced capacity for epilepsy care. The point of entry for epilepsy care and the diagnostic evaluation for surgery candidacy and the epilepsy surgery would occur at regional and district epilepsy centres in London, Hamilton, Toronto, and Ottawa and at new centres recommended for northern and eastern Ontario.
This economic analysis report was requested by OHTAC to provide information about the estimated budgetary impact on the Ontario health care system of increasing access to epilepsy surgery and to examine the cost-effectiveness of epilepsy surgery in both children and adults.
Methods
A prevalence-based “top-down” health care system budgetary impact model from the perspective of the Ministry of Health and Long-Term Care was developed to estimate the potential costs associated with expanding health care services to increase access to epilepsy care in general and epilepsy surgery in particular. A 5-year period (i.e., 2012–2016) was used to project annual costs associated with incremental epilepsy care services. Ontario Health Survey estimates of epilepsy prevalence, published epilepsy incidence data, and Canadian Census results for Ontario were used to approximate the number of individuals with epilepsy in the province. Applying these population estimates to data obtained from a recent field evaluation study that examined patterns of care and costs associated with epilepsy surgery in children, a health care system budget impact was calculated and the total costs and incremental costs associated with increasing access to surgery was estimated.
In order to examine the cost-effectiveness of epilepsy surgery in children, a decision analysis compared epilepsy surgery to continued medical management in children with medically intractable epilepsy. Data from the field evaluation were combined with various published data to estimate the costs and outcomes for children with drug-refractory epilepsy over a 20-year period. Outcomes were defined as the number of quality-adjusted life years (QALYs) accumulated over 20 years following epilepsy surgery.
Results
There are about 20,981 individuals with medically intractable epilepsy in Ontario. Of these, 9,619 (1,441 children and 8,178 adults) could potentially be further assessed at regional epilepsy centres for suitability for epilepsy surgery, following initial evaluation at a district epilepsy care centre. The health care system impact analysis related to increasing access to epilepsy surgery in the Ontario through the addition of epilepsy monitoring unit (EMU) beds with video electroencephalography (vEEG) monitoring (total capacity of 15 pediatric EMU beds and 35 adult EMU beds distributed across the province) and the associated clinical resources is estimated to require an incremental $18.1 million (Cdn) annually over the next 5 years from 2012 to 2016. This would allow for about 675 children and 1050 adults to be evaluated each year for suitability for epilepsy surgery representing a 150% increase in pediatric epilepsy surgery evaluation and a 170% increase in adult epilepsy surgery evaluation.
Epilepsy surgery was found to be cost-effective compared to continued medical management in children with drug-refractory epilepsy with the incremental cost-effectiveness ratio of $25,020 (Cdn) to $69,451 (Cdn) per QALY for 2 of the scenarios examined. In the case of choosing epilepsy surgery versus continued medical management in children known to be suitable for surgery, the epilepsy surgery was found to be less costly and provided greater clinical benefit, that is, it was the dominant strategy.
Conclusion
Epilepsy surgery for medically intractable epilepsy in suitable candidates has consistently been found to provide favourable clinical outcomes and has been demonstrated to be cost-effective in both adult and child patient populations. The first step to increasing access to epilepsy surgery is to provide access to evidence-based care for all patients with epilepsy, both adults and children, through the provision of resources to expand EMU bed capacity and associated clinical personnel across the province of Ontario.
Plain Language Summary
Epilepsy, characterized by recurrent, unpredictable, and spontaneous seizures, affects approximately 70,000 people in Ontario. About 30% continue to suffer from seizures despite using 2 or more anti-seizure medications. For these individuals epilepsy surgery is a treatment option to stop the seizures or at least reduce their frequency. Awareness of this treatment option is not widespread and people are not commonly referred to those hospitals in Ontario where this surgery is available. A proposal to increase access to epilepsy care and surgery has been made by an expert committee that provided a report to the Ontario Health Technology Advisory Committee (OHTAC). In order to address the lack of access of patients with medically intractable epilepsy to the possibility of curative surgical treatment, it is necessary to design a system that provides equal availability of evidence-based treatment for all epilepsy patients in Ontario, both adults and children. To this end, the establishment of district epilepsy care centres and the further development of the existing regional epilepsy care centres in the province have been proposed. This report outlines the estimated additional funds that will be required to implement the proposal. It also examines the cost-effectiveness of referral to these centres and epilepsy surgery.
For the 21,000 people in the province with drug-refractory epilepsy, referral to an epilepsy monitoring unit (EMU) located at one of the epilepsy care centres is the first step to determining if epilepsy surgery is an option for them. The expert committee proposal suggests that the number of EMU beds be increased from the current 19 to 50 to allow for the assessment of those individuals with drug-refractory epilepsy. The health care system budget impact model presented in this report estimates that it would cost approximately $18 million (Cdn) each year over the next 5 years to increase the number of EMU beds and expand associated epilepsy care centres to permit the systematic evidence-based care of all Ontarians with epilepsy and evaluate more people for surgery candidacy. This amount would provide appropriate care for patients with epilepsy and ensure that about 675 children and 1050 adults could be assessed each year for suitability for epilepsy surgery. Surgery could then be made available to just over 300 people per year.
Epilepsy surgery over the long term is a less expensive treatment alternative for adults and children with medically refractory epilepsy compared with continued drug treatment. In addition, drug treatment does not always work for some patients; nor does it necessarily provide improved quality of life.
This report includes a cost-effectiveness analysis comparing referral for assessment for epilepsy surgery with continuing medical management in children with drug-refractory epilepsy. In all the cases examined epilepsy surgery provides good value for money over a 20-year period. Similar studies have found that the benefits from epilepsy surgery outweigh those of continuing medical management in adult patients with medically refractory epilepsy.
PMCID: PMC3428718  PMID: 23074428
7.  Refractoriness in Sustained Visuo-Manual Control: Is the Refractory Duration Intrinsic or Does It Depend on External System Properties? 
PLoS Computational Biology  2013;9(1):e1002843.
Researchers have previously adopted the double stimulus paradigm to study refractoriness in human neuromotor control. Currently, refractoriness, such as the Psychological Refractory Period (PRP) has only been quantified in discrete movement conditions. Whether refractoriness and the associated serial ballistic hypothesis generalises to sustained control tasks has remained open for more than sixty years. Recently, a method of analysis has been presented that quantifies refractoriness in sustained control tasks and discriminates intermittent (serial ballistic) from continuous control. Following our recent demonstration that continuous control of an unstable second order system (i.e. balancing a ‘virtual’ inverted pendulum through a joystick interface) is unnecessary, we ask whether refractoriness of substantial duration (∼200 ms) is evident in sustained visual-manual control of external systems. We ask whether the refractory duration (i) is physiologically intrinsic, (ii) depends upon system properties like the order (0, 1st, and 2nd) or stability, (iii) depends upon target jump direction (reversal, same direction). Thirteen participants used discrete movements (zero order system) as well as more sustained control activity (1st and 2nd order systems) to track unpredictable step-sequence targets. Results show a substantial refractory duration that depends upon system order (250, 350 and 550 ms for 0, 1st and 2nd order respectively, n = 13, p<0.05), but not stability. In sustained control refractoriness was only found when the target reverses direction. In the presence of time varying actuators, systems and constraints, we propose that central refractoriness is an appropriate control mechanism for accommodating online optimization delays within the neural circuitry including the more variable processing times of higher order (complex) input-output relations.
Author Summary
In biology, the control of physiological variables such as body position, blood pressure and body temperature is founded on negative feedback mechanisms governing homeostasic input-output relations. The conceptual models capturing the underlying control principles are often drawn from engineering control theory. The visuo-manual control of external systems (like balancing a stick on the palm of one's hand) has traditionally been interpreted using continuous paradigms such as the servo controller or the continuous optimal controller. These engineering controllers were designed for machine systems with precise sensors, consistent actuators, short time delays and fast computers. Quite the opposite is true for the human movement system that is characterized by long neuromuscular delays, variability, history dependence and fatigue. Serial ballistic control offers an alternative control paradigm in which smooth control proceeds as a sequence of sub-movements each planned using current sensory information but then intermittently executed “open loop”. In the current study we are the first to formally identify refractoriness, a behavioural characteristic that discriminates intermittent (serial ballistic) from continuous control, in the domain of sustained (non-discrete) control of first and second order systems providing definite evidence for the validity of intermittent open-loop control as a paradigm for sustained human control.
doi:10.1371/journal.pcbi.1002843
PMCID: PMC3536613  PMID: 23300430
8.  CGBayesNets: Conditional Gaussian Bayesian Network Learning and Inference with Mixed Discrete and Continuous Data 
PLoS Computational Biology  2014;10(6):e1003676.
Bayesian Networks (BN) have been a popular predictive modeling formalism in bioinformatics, but their application in modern genomics has been slowed by an inability to cleanly handle domains with mixed discrete and continuous variables. Existing free BN software packages either discretize continuous variables, which can lead to information loss, or do not include inference routines, which makes prediction with the BN impossible. We present CGBayesNets, a BN package focused around prediction of a clinical phenotype from mixed discrete and continuous variables, which fills these gaps. CGBayesNets implements Bayesian likelihood and inference algorithms for the conditional Gaussian Bayesian network (CGBNs) formalism, one appropriate for predicting an outcome of interest from, e.g., multimodal genomic data. We provide four different network learning algorithms, each making a different tradeoff between computational cost and network likelihood. CGBayesNets provides a full suite of functions for model exploration and verification, including cross validation, bootstrapping, and AUC manipulation. We highlight several results obtained previously with CGBayesNets, including predictive models of wood properties from tree genomics, leukemia subtype classification from mixed genomic data, and robust prediction of intensive care unit mortality outcomes from metabolomic profiles. We also provide detailed example analysis on public metabolomic and gene expression datasets. CGBayesNets is implemented in MATLAB and available as MATLAB source code, under an Open Source license and anonymous download at http://www.cgbayesnets.com.
doi:10.1371/journal.pcbi.1003676
PMCID: PMC4055564  PMID: 24922310
9.  Community-Based Care for the Specialized Management of Heart Failure 
Executive Summary
In August 2008, the Medical Advisory Secretariat (MAS) presented a vignette to the Ontario Health Technology Advisory Committee (OHTAC) on a proposed targeted health care delivery model for chronic care. The proposed model was defined as multidisciplinary, ambulatory, community-based care that bridged the gap between primary and tertiary care, and was intended for individuals with a chronic disease who were at risk of a hospital admission or emergency department visit. The goals of this care model were thought to include: the prevention of emergency department visits, a reduction in hospital admissions and re-admissions, facilitation of earlier hospital discharge, a reduction or delay in long-term care admissions, and an improvement in mortality and other disease-specific patient outcomes.
OHTAC approved the development of an evidence-based assessment to determine the effectiveness of specialized community based care for the management of heart failure, Type 2 diabetes and chronic wounds.
Please visit the Medical Advisory Secretariat Web site at: www.health.gov.on.ca/ohtas to review the following reports associated with the Specialized Multidisciplinary Community-Based care series.
Specialized multidisciplinary community-based care series: a summary of evidence-based analyses
Community-based care for the specialized management of heart failure: an evidence-based analysis
Community-based care for chronic wound management: an evidence-based analysis
Please note that the evidence-based analysis of specialized community-based care for the management of diabetes titled: “Community-based care for the management of type 2 diabetes: an evidence-based analysis” has been published as part of the Diabetes Strategy Evidence Platform at this URL: http://www.health.gov.on.ca/english/providers/program/mas/tech/ohtas/tech_diabetes_20091020.html
Please visit the Toronto Health Economics and Technology Assessment Collaborative Web site at: http://theta.utoronto.ca/papers/MAS_CHF_Clinics_Report.pdf to review the following economic project associated with this series:
Community-based Care for the specialized management of heart failure: a cost-effectiveness and budget impact analysis.
Objective
The objective of this evidence-based analysis was to determine the effectiveness of specialized multidisciplinary care in the management of heart failure (HF).
Clinical Need: Target Population and Condition
HF is a progressive, chronic condition in which the heart becomes unable to sufficiently pump blood throughout the body. There are several risk factors for developing the condition including hypertension, diabetes, obesity, previous myocardial infarction, and valvular heart disease.(1) Based on data from a 2005 study of the Canadian Community Health Survey (CCHS), the prevalence of congestive heart failure in Canada is approximately 1% of the population over the age of 12.(2) This figure rises sharply after the age of 45, with prevalence reports ranging from 2.2% to 12%.(3) Extrapolating this to the Ontario population, an estimated 98,000 residents in Ontario are believed to have HF.
Disease management programs are multidisciplinary approaches to care for chronic disease that coordinate comprehensive care strategies along the disease continuum and across healthcare delivery systems.(4) Evidence for the effectiveness of disease management programs for HF has been provided by seven systematic reviews completed between 2004 and 2007 (Table 1) with consistency of effect demonstrated across four main outcomes measures: all cause mortality and hospitalization, and heart-failure specific mortality and hospitalization. (4-10)
However, while disease management programs are multidisciplinary by definition, the published evidence lacks consistency and clarity as to the exact nature of each program and usual care comparators are generally ill defined. Consequently, the effectiveness of multidisciplinary care for the management of persons with HF is still uncertain. Therefore, MAS has completed a systematic review of specialized, multidisciplinary, community-based care disease management programs compared to a well-defined usual care group for persons with HF.
Evidence-Based Analysis Methods
Research Questions
What is the effectiveness of specialized, multidisciplinary, community-based care (SMCCC) compared with usual care for persons with HF?
Literature Search Strategy
A comprehensive literature search was completed of electronic databases including MEDLINE, MEDLINE In-Process and Other Non-Indexed Citations, EMBASE, Cochrane Library and Cumulative Index to Nursing & Allied Health Literature. Bibliographic references of selected studies were also searched. After a review of the title and abstracts, relevant studies were obtained and the full reports evaluated. All studies meeting explicit inclusion and exclusion criteria were retained. Where appropriate, a meta-analysis was undertaken to determine the pooled estimate of effect of specialized multidisciplinary community-based care for explicit outcomes. The quality of the body of evidence, defined as one or more relevant studies was determined using GRADE Working Group criteria. (11)
Inclusion Criteria
Randomized controlled trial
Systematic review with meta analysis
Population includes persons with New York Heart Association (NYHA) classification 1-IV HF
The intervention includes a team consisting of a nurse and physician one of which is a specialist in HF management.
The control group receives care by a single practitioner (e.g. primary care physician (PCP) or cardiologist)
The intervention begins after discharge from the hospital
The study reports 1-year outcomes
Exclusion Criteria
The intervention is delivered predominately through home-visits
Studies with mixed populations where discrete data for HF is not reported
Outcomes of Interest
All cause mortality
All cause hospitalization
HF specific mortality
HF specific hospitalization
All cause duration of hospital stay
HF specific duration of hospital stay
Emergency room visits
Quality of Life
Summary of Findings
One large and seven small randomized controlled trials were obtained from the literature search.
A meta-analysis was completed for four of the seven outcomes including:
All cause mortality
HF-specific mortality
All cause hospitalization
HF-specific hospitalization.
Where the pooled analysis was associated with significant heterogeneity, subgroup analyses were completed using two primary categories:
direct and indirect model of care; and
type of control group (PCP or cardiologist).
The direct model of care was a clinic-based multidisciplinary HF program and the indirect model of care was a physician supervised, nurse-led telephonic HF program.
All studies, except one, were completed in jurisdictions outside North America. (12-19) Similarly, all but one study had a sample size of less than 250. The mean age in the studies ranged from 65 to 77 years. Six of the studies(12;14-18) included populations with a NYHA classification of II-III. In two studies, the control treatment was a cardiologist (12;15) and two studies reported the inclusion of a dietitian, physiotherapist and psychologist as members of the multidisciplinary team (12;19).
All Cause Mortality
Eight studies reported all cause mortality (number of persons) at 1 year follow-up. (12-19) When the results of all eight studies were pooled, there was a statistically significant RRR of 29% with moderate heterogeneity (I2 of 38%). The results of the subgroup analyses indicated a significant RRR of 40% in all cause mortality when SMCCC is delivered through a direct team model (clinic) and a 35% RRR when SMCCC was compared with a primary care practitioner.
HF-Specific Mortality
Three studies reported HF-specific mortality (number of persons) at 1 year follow-up. (15;18;19) When the results of these were pooled, there was an insignificant RRR of 42% with high statistical heterogeneity (I2 of 60%). The GRADE quality of evidence is moderate for the pooled analysis of all studies.
All Cause Hospitalization
Seven studies reported all cause hospitalization at 1-year follow-up (13-15;17-19). When pooled, their results showed a statistically insignificant 12% increase in hospitalizations in the SMCCC group with high statistical heterogeneity (I2 of 81%). A significant RRR of 12% in all cause hospitalization in favour of the SMCCC care group was achieved when SMCCC was delivered using an indirect model (telephonic) with an associated (I2 of 0%). The Grade quality of evidence was found to be low for the pooled analysis of all studies and moderate for the subgroup analysis of the indirect team care model.
HF-Specific Hospitalization
Six studies reported HF-specific hospitalization at 1-year follow-up. (13-15;17;19) When pooled, the results of these studies showed an insignificant RRR of 14% with high statistical heterogeneity (I2 of 60%); however, the quality of evidence for the pooled analysis of was low.
Duration of Hospital Stay
Seven studies reported duration of hospital stay, four in terms of mean duration of stay in days (14;16;17;19) and three in terms of total hospital bed days (12;13;18). Most studies reported all cause duration of hospital stay while two also reported HF-specific duration of hospital stay. These data were not amenable to meta-analyses as standard deviations were not provided in the reports. However, in general (and in all but one study) it appears that persons receiving SMCCC had shorter hospital stays, whether measured as mean days in hospital or total hospital bed days.
Emergency Room Visits
Only one study reported emergency room visits. (14) This was presented as a composite of readmissions and ER visits, where the authors reported that 77% (59/76) of the SMCCC group and 84% (63/75) of the usual care group were either readmitted or had an ER visit within the 1 year of follow-up (P=0.029).
Quality of Life
Quality of life was reported in five studies using the Minnesota Living with HF Questionnaire (MLHFQ) (12-15;19) and in one study using the Nottingham Health Profile Questionnaire(16). The MLHFQ results are reported in our analysis. Two studies reported the mean score at 1 year follow-up, although did not provide the standard deviation of the mean in their report. One study reported the median and range scores at 1 year follow-up in each group. Two studies reported the change scores of the physical and emotional subscales of the MLHFQ of which only one study reported a statistically significant change from baseline to 1 year follow-up between treatment groups in favour of the SMCCC group in the physical sub-scale. A significant change in the emotional subscale scores from baseline to 1 year follow-up in the treatment groups was not reported in either study.
Conclusion
There is moderate quality evidence that SMCCC reduces all cause mortality by 29%. There is low quality evidence that SMCCC contributes to a shorter duration of hospital stay and improves quality of life compared to usual care. The evidence supports that SMCCC is effective when compared to usual care provided by either a primary care practitioner or a cardiologist. It does not, however, suggest an optimal model of care or discern what the effective program components are. A field evaluation could address this uncertainty.
PMCID: PMC3377506  PMID: 23074521
10.  An Analytic Strategy for Modeling Multiple-Item Responses 
Nursing research  2005;54(4):229-234.
Background
Item Response Theory (IRT) is increasingly applied in health research to combine information from multiple-item responses. IRT posits that a person's susceptibility to a symptom is driven by the interaction of the characteristics of the symptom and person. This article describes the statistical background of incorporating IRT into a multilevel framework and extends this approach to longitudinal health outcomes, where the self-report method is used to construct a multi-item scale.
Methods
A secondary analysis of data from 2 descriptive longitudinal studies is performed. The data include 21 symptoms reported across time by 350 women with breast cancer. A 3-level hierarchical linear model (HLM) was used for the analysis. Level 1 models the item responses, consisting of symptom presence or absence. Level 2 models the trajectory of each individual, representing change over time of the IRT-created latent variable symptom experience. Level 3 explains that trajectory using person-specific characteristics such as age and location of care. The purpose of the analysis is to examine if older and younger women with breast cancer differ in their symptom experience trajectory after controlling for location of care.
Results
Fatigue and pain were the most prevalent symptoms. The symptom experience of women with breast cancer was found to improve over time. Neither age nor location of care was significantly associated with the symptom experience trajectory.
Discussion
Embedding IRT into an HLM framework produces several benefits. The example provided demonstrates benefits through the creation of a latent symptom experience variable that can be used either as an outcome or as a covariate in another model, examining the latent symptom experience trajectory and its relationship with covariates at the individual level, and managing symptom nonresponse.
PMCID: PMC1839066  PMID: 16027565
cancer symptoms; hierarchical linear model; Item Response Theory; women with breast cancer
11.  Using a Bayesian latent growth curve model to identify trajectories of positive affect and negative events following myocardial infarction 
Biostatistics (Oxford, England)  2005;6(1):119-143.
Summary
Positive and negative affect data are often collected over time in psychiatric care settings, yet no generally accepted means are available to relate these data to useful diagnoses or treatments. Latent class analysis attempts data reduction by classifying subjects into one of K unobserved classes based on observed data. Latent class models have recently been extended to accommodate longitudinally observed data. We extend these approaches in a Bayesian framework to accommodate trajectories of both continuous and discrete data. We consider whether latent class models might be used to distinguish patients on the basis of trajectories of observed affect scores, reported events, and presence or absence of clinical depression.
doi:10.1093/biostatistics/kxh022
PMCID: PMC2827342  PMID: 15618532
Cardiovascular disease; Depression; DIC; General growth mixture modeling; Gibbs sampling; Label switching; Model choice
12.  Home Telemonitoring for Type 2 Diabetes 
Executive Summary
In June 2008, the Medical Advisory Secretariat began work on the Diabetes Strategy Evidence Project, an evidence-based review of the literature surrounding strategies for successful management and treatment of diabetes. This project came about when the Health System Strategy Division at the Ministry of Health and Long-Term Care subsequently asked the secretariat to provide an evidentiary platform for the Ministry’s newly released Diabetes Strategy.
After an initial review of the strategy and consultation with experts, the secretariat identified five key areas in which evidence was needed. Evidence-based analyses have been prepared for each of these five areas: insulin pumps, behavioural interventions, bariatric surgery, home telemonitoring, and community based care. For each area, an economic analysis was completed where appropriate and is described in a separate report.
To review these titles within the Diabetes Strategy Evidence series, please visit the Medical Advisory Secretariat Web site, http://www.health.gov.on.ca/english/providers/program/mas/mas_about.html,
Diabetes Strategy Evidence Platform: Summary of Evidence-Based Analyses
Continuous Subcutaneous Insulin Infusion Pumps for Type 1 and Type 2 Adult Diabetics: An Evidence-Based Analysis
Behavioural Interventions for Type 2 Diabetes: An Evidence-Based Analysis
Bariatric Surgery for People with Diabetes and Morbid Obesity: An Evidence-Based Summary
Community-Based Care for the Management of Type 2 Diabetes: An Evidence-Based Analysis
Home Telemonitoring for Type 2 Diabetes: An Evidence-Based Analysis
Application of the Ontario Diabetes Economic Model (ODEM) to Determine the Cost-effectiveness and Budget Impact of Selected Type 2 Diabetes Interventions in Ontario
Objective
The objective of this report is to determine whether home telemonitoring and management of blood glucose is effective for improving glycemic control in adults with type 2 diabetes.
Background
An aging population coupled with a shortage of nurses and physicians in Ontario is increasing the demand for home care services for chronic diseases, including diabetes. In recent years, there has also been a concurrent rise in the number of blood glucose home telemonitoring technologies available for diabetes management. The Canadian Diabetes Association (CDA) currently recommends self-monitoring of blood glucose for patients with type 2 diabetes, particularly for individuals using insulin. With the emergence of home telemonitoring, there is potential for improving the impact of self-monitoring by linking patients with health care professionals who can monitor blood glucose values and then provide guided recommendations remotely. The MAS has, therefore, conducted a review of the available evidence on blood glucose home telemonitoring and management technologies for type 2 diabetes.
Evidence-Based Analysis of Effectiveness
Research Question
Is home telemonitoring of blood glucose for adults with type 2 diabetes more efficacious in improving glycemic control (i.e. can it reduce HbA1c levels) in comparison to usual care?
Literature Search
Inclusion Criteria
Intervention: Must involve the frequent transmission of remotely-collected blood glucose measurements by patients to health care professionals for routine monitoring through the use of home telemonitoring technology.
Intervention: Monitoring must be combined with a coordinated management and feedback system based on transmitted data.
Control: Usual diabetes care as provided by the usual care provider (usual care largely varies by jurisdiction and study).
Population: Adults ≥18 years of age with type 2 diabetes.
Follow-up: ≥6 months.
Sample size: ≥30 patients total.
Publication type: Randomized controlled trials (RCTs), systematic reviews, and/or meta-analyses.
Publication date range: January 1, 1998 to January 31, 2009.
Exclusion Criteria
Studies with a control group other than usual care.
Studies published in a language other than English.
Studies in which there is indication that the monitoring of patients’ diabetic measurements by a health care professional(s) was not occurring more frequently in intervention patients than in control patients receiving usual care.
Outcomes of Interest
The primary outcome of interest was a reduction in glycosylated hemoglobin (HbA1c) levels.
Search Strategy
A comprehensive literature search was performed in OVID MEDLINE, MEDLINE In-Process and Other Non-Indexed Citations, EMBASE, CINAHL, The Cochrane Library, and INAHTA for studies published between January 1, 2007 and January 31, 2009. The search was designed as a continuation of a search undertaken for a systematic review by the Canadian Agency for Drugs and Technologies in Health, originally encompassing studies published from 1950 up until July of 2008 and which reviewed home telemonitoring in comparison to usual care for the management of type 1 and type 2 diabetes.
Summary of Findings
A total of eight studies identified by the literature search were eligible for inclusion (one was excluded post-hoc from analysis). Studies varied considerably on characteristics of design, population, and intervention/control. Of note, few trials limited populations to type 2 diabetics only, thus trials with mixed populations (type 1 and type 2) were included, though in such cases, the majority of patients (>60%) had type 2 diabetes. No studies restricted inclusion or analyses by diabetes treatment type (i.e. populations were mixed with respect to those on insulin therapy vs. not) and studies further varied on whether intervention was provided in addition to usual care or as a replacement. Lastly, trials often included blood glucose home telemonitoring as an adjunct to other telemedicine components and thus the incremental value of adding home telemonitoring remains unclear. The overall grading of the quality of evidence was low, indicating that there is uncertainty in the findings.
Meta-analysis of the seven trials identified a moderate but significant reduction in HbA1c levels (~0.5% reduction) in favour blood glucose home telemonitoring compared to usual care for adults with type 2 diabetes). Subgroup analyses suggested differences in effect size depending on the type of intervention, however, these findings should be held under caution as the analyses were exploratory in nature and intervention components overlapped between subgroups.
Meta-Analyses of Reduction in HbA1c Values for Analyzed Studies
Conclusions
Based on low quality evidence, blood glucose home telemonitoring technologies confer a statistically significant reduction in HbA1c of ~0.50% in comparison to usual care when used adjunctively to a broader telemedicine initiative for adults with type 2 diabetes.
Exploratory analysis suggests differences in effect sizes for the primary outcome when analyzing by subgroup; however, this should only be viewed as exploratory or hypothesis-generating only.
Significant limitations and/or sources of clinical heterogeneity are present in the available literature, generating great uncertainty in conclusions.
More robust trials in type 2 diabetics only, utilizing more modern technologies, preferably performed in an Ontario or a similar setting (given the infrastructure demands and that the standard comparator is usual care), while separating out the effects of other telemedicine intervention components, are needed to clarify the effect of emerging remote blood glucose monitoring technologies.
PMCID: PMC3377533  PMID: 23074529
13.  Evidence for the Continuous Latent Structure of Mania in the Epidemiologic Catchment Area from Multiple Latent Structure and Construct Validation Methodologies 
Psychological medicine  2010;41(3):575-588.
Background
Although psychiatric diagnostic systems have conceptualized mania as a discrete phenomenon, appropriate latent structure investigations testing this conceptualization are lacking. In contrast to these diagnostic systems, several influential theories of mania have suggested a continuous conceptualization. The present study examined whether mania has a continuous or discrete latent structure using a comprehensive approach including taxometric, information-theoretic latent distribution modeling (ITLDM), and predictive validity methodologies in the Epidemiologic Catchment Area (ECA) study.
Methods
Eight dichotomous manic symptom items were submitted to a variety of latent structural analyses; including factor analyses, taxometric procedures, and ITLDM; in 10,105 ECA community participants. Additionally, a variety of continuous and discrete models of mania were compared in terms of their relative abilities to predict outcomes (i.e., health service utilization, internalizing and externalizing disorders, and suicidal behavior).
Results
Taxometric and ITLDM analyses consistently supported a continuous conceptualization of mania. In ITLDM analyses, a continuous model of mania demonstrated 6:52:1 odds over the best fitting latent class model of mania. Factor analyses suggested that the continuous structure of mania was best represented by a single latent factor. Predictive validity analyses demonstrated a consistent superior ability of continuous models of mania relative to discrete models.
Conclusions
The present study provided three independent lines of support for a continuous conceptualization of mania. The implications of a continuous model of mania are discussed.
doi:10.1017/S0033291710001078
PMCID: PMC3142574  PMID: 20507671
14.  Intensive case management for severe mental illness 
Background
Intensive Case Management (ICM) is a community based package of care, aiming to provide long term care for severely mentally ill people who do not require immediate admission. ICM evolved from two original community models of care, Assertive Community Treatment (ACT) and Case Management (CM), where ICM emphasises the importance of small caseload (less than 20) and high intensity input.
Objectives
To assess the effects of Intensive Case Management (caseload <20) in comparison with non-Intensive Case Management (caseload > 20) and with standard community care in people with severe mental illness. To evaluate whether the effect of ICM on hospitalisation depends on its fidelity to the ACT model and on the setting.
Search methods
For the current update of this review we searched the Cochrane Schizophrenia Group Trials Register (February 2009), which is compiled by systematic searches of major databases, hand searches and conference proceedings.
Selection criteria
All relevant randomised clinical trials focusing on people with severe mental illness, aged 18 to 65 years and treated in the community-care setting, where Intensive Case Management, non-Intensive Case Management or standard care were compared. Outcomes such as service use, adverse effects, global state, social functioning, mental state, behaviour, quality of life, satisfaction and costs were sought.
Data collection and analysis
We extracted data independently. For binary outcomes we calculated relative risk (RR) and its 95% confidence interval (CI), on an intention-to-treat basis. For continuous data we estimated mean difference (MD) between groups and its 95% confidence interval (CI). We employed a random-effects model for analyses.
We performed a random-effects meta-regression analysis to examine the association of the intervention’s fidelity to the ACT model and the rate of hospital use in the setting where the trial was conducted with the treatment effect.
Main results
We included 38 trials (7328 participants) in this review. The trials provided data for two comparisons: 1. ICM versus standard care, 2. ICM versus non-ICM.
1. ICM versus standard care
Twenty-four trials provided data on length of hospitalisation, and results favoured Intensive Case Management (n=3595, 24 RCTs, MD −0.86 CI −1.37 to −0.34). There was a high level of heterogeneity, but this significance still remained when the outlier studies were excluded from the analysis (n=3143, 20 RCTs, MD −0.62 CI −1.00 to −0.23). Nine studies found participants in the ICM group were less likely to be lost to psychiatric services (n=1633, 9 RCTs, RR 0.43 CI 0.30 to 0.61, I2=49%, p=0.05).
One global state scale did show an Improvement in global state for those receiving ICM, the GAF scale (n=818, 5 RCTs, MD 3.41 CI 1.66 to 5.16). Results for mental state as measured through various rating scales, however, were equivocal, with no compelling evidence that ICM was really any better than standard care in improving mental state. No differences in mortality between ICM and standard care groups occurred, either due to ’all causes’ (n=1456, 9 RCTs, RR 0.84 CI 0.48 to 1.47) or to ’suicide’ (n=1456, 9 RCTs, RR 0.68 CI 0.31 to 1.51).
Social functioning results varied, no differences were found in terms of contact with the legal system and with employment status, whereas significant improvement in accommodation status was found, as was the incidence of not living independently, which was lower in the ICM group (n=1185, 4 RCTs, RR 0.65 CI 0.49 to 0.88).
Quality of life data found no significant difference between groups, but data were weak. CSQ scores showed a greater participant satisfaction in the ICM group (n=423, 2 RCTs, MD 3.23 CI 2.31 to 4.14).
2. ICM versus non-ICM
The included studies failed to show a significant advantage of ICM in reducing the average length of hospitalisation (n=2220, 21 RCTs, MD −0.08 CI −0.37 to 0.21). They did find ICM to be more advantageous than non-ICM in reducing rate of lost to follow-up (n= 2195, 9 RCTs, RR 0.72 CI 0.52 to 0.99), although data showed a substantial level of heterogeneity (I2=59%, p=0.01). Overall, no significant differences were found in the effects of ICM compared to non-ICM for broad outcomes such as service use, mortality, social functioning, mental state, behaviour, quality of life, satisfaction and costs.
3. Fidelity to ACT
Within the meta-regression we found that i. the more ICM is adherent to the ACT model, the better it is at decreasing time in hospital (’organisation fidelity’ variable coefficient −0.36 CI −0.66 to −0.07); and ii. the higher the baseline hospital use in the population, the better ICM is at decreasing time in hospital (’baseline hospital use’ variable coefficient −0.20 CI −0.32 to −0.10). Combining both these variables within the model, ’organisation fidelity’ is no longer significant, but ’baseline hospital use’ result is still significantly influencing time in hospital (regression coefficient −0.18 CI −0.29 to −0.07, p=0.0027).
Authors’ conclusions
ICM was found effective in ameliorating many outcomes relevant to people with severe mental illnesses. Compared to standard care ICM was shown to reduce hospitalisation and increase retention in care. It also globally improved social functioning, although ICM’s effect on mental state and quality of life remains unclear. ICM is of value at least to people with severe mental illnesses who are in the sub-group of those with a high level of hospitalisation (about 4 days/month in past 2 years) and the intervention should be performed close to the original model.
It is not clear, however, what gain ICM provides on top of a less formal non-ICM approach.
We do not think that more trials comparing current ICM with standard care or non-ICM are justified, but currently we know of no review comparing non-ICM with standard care and this should be undertaken.
doi:10.1002/14651858.CD007906.pub2
PMCID: PMC4233116  PMID: 20927766
*Case Management; Community Mental Health Services [*methods]; Hospitalization [statistics & numerical data]; Mental Disorders [*therapy]; Outcome and Process Assessment (Health Care) [*methods]; Randomized Controlled Trials as Topic; Humans
15.  Community-Based Multidisciplinary Care for Patients With Stable Chronic Obstructive Pulmonary Disease (COPD) 
Executive Summary
In July 2010, the Medical Advisory Secretariat (MAS) began work on a Chronic Obstructive Pulmonary Disease (COPD) evidentiary framework, an evidence-based review of the literature surrounding treatment strategies for patients with COPD. This project emerged from a request by the Health System Strategy Division of the Ministry of Health and Long-Term Care that MAS provide them with an evidentiary platform on the effectiveness and cost-effectiveness of COPD interventions.
After an initial review of health technology assessments and systematic reviews of COPD literature, and consultation with experts, MAS identified the following topics for analysis: vaccinations (influenza and pneumococcal), smoking cessation, multidisciplinary care, pulmonary rehabilitation, long-term oxygen therapy, noninvasive positive pressure ventilation for acute and chronic respiratory failure, hospital-at-home for acute exacerbations of COPD, and telehealth (including telemonitoring and telephone support). Evidence-based analyses were prepared for each of these topics. For each technology, an economic analysis was also completed where appropriate. In addition, a review of the qualitative literature on patient, caregiver, and provider perspectives on living and dying with COPD was conducted, as were reviews of the qualitative literature on each of the technologies included in these analyses.
The Chronic Obstructive Pulmonary Disease Mega-Analysis series is made up of the following reports, which can be publicly accessed at the MAS website at: http://www.hqontario.ca/en/mas/mas_ohtas_mn.html.
Chronic Obstructive Pulmonary Disease (COPD) Evidentiary Framework
Influenza and Pneumococcal Vaccinations for Patients With Chronic Obstructive Pulmonary Disease (COPD): An Evidence-Based Analysis
Smoking Cessation for Patients With Chronic Obstructive Pulmonary Disease (COPD): An Evidence-Based Analysis
Community-Based Multidisciplinary Care for Patients With Stable Chronic Obstructive Pulmonary Disease (COPD): An Evidence-Based Analysis
Pulmonary Rehabilitation for Patients With Chronic Obstructive Pulmonary Disease (COPD): An Evidence-Based Analysis
Long-term Oxygen Therapy for Patients With Chronic Obstructive Pulmonary Disease (COPD): An Evidence-Based Analysis
Noninvasive Positive Pressure Ventilation for Acute Respiratory Failure Patients With Chronic Obstructive Pulmonary Disease (COPD): An Evidence-Based Analysis
Noninvasive Positive Pressure Ventilation for Chronic Respiratory Failure Patients With Stable Chronic Obstructive Pulmonary Disease (COPD): An Evidence-Based Analysis
Hospital-at-Home Programs for Patients With Acute Exacerbations of Chronic Obstructive Pulmonary Disease (COPD): An Evidence-Based Analysis
Home Telehealth for Patients With Chronic Obstructive Pulmonary Disease (COPD): An Evidence-Based Analysis
Cost-Effectiveness of Interventions for Chronic Obstructive Pulmonary Disease Using an Ontario Policy Model
Experiences of Living and Dying With COPD: A Systematic Review and Synthesis of the Qualitative Empirical Literature
For more information on the qualitative review, please contact Mita Giacomini at: http://fhs.mcmaster.ca/ceb/faculty_member_giacomini.htm.
For more information on the economic analysis, please visit the PATH website: http://www.path-hta.ca/About-Us/Contact-Us.aspx.
The Toronto Health Economics and Technology Assessment (THETA) collaborative has produced an associated report on patient preference for mechanical ventilation. For more information, please visit the THETA website: http://theta.utoronto.ca/static/contact.
Objective
The objective of this evidence-based analysis was to determine the effectiveness and cost-effectiveness of multidisciplinary care (MDC) compared with usual care (UC, single health care provider) for the treatment of stable chronic obstructive pulmonary disease (COPD).
Clinical Need: Condition and Target Population
Chronic obstructive pulmonary disease is a progressive disorder with episodes of acute exacerbations associated with significant morbidity and mortality. Cigarette smoking is linked causally to COPD in more than 80% of cases. Chronic obstructive pulmonary disease is among the most common chronic diseases worldwide and has an enormous impact on individuals, families, and societies through reduced quality of life and increased health resource utilization and mortality.
The estimated prevalence of COPD in Ontario in 2007 was 708,743 persons.
Technology
Multidisciplinary care involves professionals from a range of disciplines, working together to deliver comprehensive care that addresses as many of the patient’s health care and psychosocial needs as possible.
Two variables are inherent in the concept of a multidisciplinary team: i) the multidisciplinary components such as an enriched knowledge base and a range of clinical skills and experiences, and ii) the team components, which include but are not limited to, communication and support measures. However, the most effective number of team members and which disciplines should comprise the team for optimal effect is not yet known.
Research Question
What is the effectiveness and cost-effectiveness of MDC compared with UC (single health care provider) for the treatment of stable COPD?
Research Methods
Literature Search
Search Strategy
A literature search was performed on July 19, 2010 using OVID MEDLINE, OVID MEDLINE In-Process and Other Non-Indexed Citations, OVID EMBASE, EBSCO Cumulative Index to Nursing & Allied Health Literature (CINAHL), the Wiley Cochrane Library, and the Centre for Reviews and Dissemination database, for studies published from January 1, 1995 until July 2010. Abstracts were reviewed by a single reviewer and, for those studies meeting the eligibility criteria, full-text articles were obtained. Reference lists were also examined for any additional relevant studies not identified through the search.
Inclusion Criteria
health technology assessments, systematic reviews, or randomized controlled trials
studies published between January 1995 and July 2010;
COPD study population
studies comparing MDC (2 or more health care disciplines participating in care) compared with UC (single health care provider)
Exclusion Criteria
grey literature
duplicate publications
non-English language publications
study population less than 18 years of age
Outcomes of Interest
hospital admissions
emergency department (ED) visits
mortality
health-related quality of life
lung function
Quality of Evidence
The quality of each included study was assessed, taking into consideration allocation concealment, randomization, blinding, power/sample size, withdrawals/dropouts, and intention-to-treat analyses.
The quality of the body of evidence was assessed as high, moderate, low, or very low according to the GRADE Working Group criteria. The following definitions of quality were used in grading the quality of the evidence:
Summary of Findings
Six randomized controlled trials were obtained from the literature search. Four of the 6 studies were completed in the United States. The sample size of the 6 studies ranged from 40 to 743 participants, with a mean study sample between 66 and 71 years of age. Only 2 studies characterized the study sample in terms of the Global Initiative for Chronic Obstructive Lung Disease (GOLD) COPD stage criteria, and in general the description of the study population in the other 4 studies was limited. The mean percent predicted forced expiratory volume in 1 second (% predicted FEV1) among study populations was between 32% and 59%. Using this criterion, 3 studies included persons with severe COPD and 2 with moderate COPD. Information was not available to classify the population in the sixth study.
Four studies had MDC treatment groups which included a physician. All studies except 1 reported a respiratory specialist (i.e., respiratory therapist, specialist nurse, or physician) as part of the multidisciplinary team. The UC group was comprised of a single health care practitioner who may or may not have been a respiratory specialist.
A meta-analysis was completed for 5 of the 7 outcome measures of interest including:
health-related quality of life,
lung function,
all-cause hospitalization,
COPD-specific hospitalization, and
mortality.
There was only 1 study contributing to the outcome of all-cause and COPD-specific ED visits which precluded pooling data for these outcomes. Subgroup analyses were not completed either because heterogeneity was not significant or there were a small number of studies that were meta-analysed for the outcome.
Quality of Life
Three studies reported results of quality of life assessment based on the St. George’s Respiratory Questionnaire (SGRQ). A mean decrease in the SGRQ indicates an improvement in quality of life while a mean increase indicates deterioration in quality of life. In all studies the mean change score from baseline to the end time point in the MDC treatment group showed either an improvement compared with the control group or less deterioration compared with the control group. The mean difference in change scores between MDC and UC groups was statistically significant in all 3 studies. The pooled weighted mean difference in total SGRQ score was −4.05 (95% confidence interval [CI], −6.47 to 1.63; P = 0.001). The GRADE quality of evidence was assessed as low for this outcome.
Lung Function
Two studies reported results of the FEV1 % predicted as a measure of lung function. A negative change from baseline infers deterioration in lung function and a positive change from baseline infers an improvement in lung function. The MDC group showed a statistically significant improvement in lung function up to 12 months compared with the UC group (P = 0.01). However this effect is not maintained at 2-year follow-up (P = 0.24). The pooled weighted mean difference in FEV1 percent predicted was 2.78 (95% CI, −1.82 to −7.37). The GRADE quality of evidence was assessed as very low for this outcome indicating that an estimate of effect is uncertain.
Hospital Admissions
All-Cause
Four studies reported results of all-cause hospital admissions in terms of number of persons with at least 1 admission during the follow-up period. Estimates from these 4 studies were pooled to determine a summary estimate. There is a statistically significant 25% relative risk (RR) reduction in all-cause hospitalizations in the MDC group compared with the UC group (P < 0.001). The index of heterogeneity (I2) value is 0%, indicating no statistical heterogeneity between studies. The GRADE quality of evidence was assessed as moderate for this outcome, indicating that further research may change the estimate of effect.
COPD-Specific Hospitalization
Three studies reported results of COPD-specific hospital admissions in terms of number of persons with at least 1 admission during the follow-up period. Estimates from these 3 studies were pooled to determine a summary estimate. There is a statistically significant 33% RR reduction in all-cause hospitalizations in the MDC group compared with the UC group (P = 0.002). The I2 value is 0%, indicating no statistical heterogeneity between studies. The GRADE quality of evidence was assessed as moderate for this outcome, indicating that further research may change the estimate of effect.
Emergency Department Visits
All-Cause
Two studies reported results of all-cause ED visits in terms of number of persons with at least 1 visit during the follow-up period. There is a statistically nonsignificant reduction in all-cause ED visits when data from these 2 studies are pooled (RR, 0.64; 95% CI, 0.31 to −1.33; P = 0.24). The GRADE quality of evidence was assessed as very low for this outcome indicating that an estimate of effect is uncertain.
COPD-Specific
One study reported results of COPD-specific ED visits in terms of number of persons with at least 1 visit during the follow-up period. There is a statistically significant 41% reduction in COPD-specific ED visits when the data from these 2 studies are pooled (RR, 0.59; 95% CI, 0.43−0.81; P < 0.001). The GRADE quality of evidence was assessed as moderate for this outcome.
Mortality
Three studies reported the mortality during the study follow-up period. Estimates from these 3 studies were pooled to determine a summary estimate. There is a statistically nonsignificant reduction in mortality between treatment groups (RR, 0.81; 95% CI, 0.52−1.27; P = 0.36). The I2 value is 19%, indicating low statistical heterogeneity between studies. All studies had a 12-month follow-up period. The GRADE quality of evidence was assessed as low for this outcome.
Conclusions
Significant effect estimates with moderate quality of evidence were found for all-cause hospitalization, COPD-specific hospitalization, and COPD-specific ED visits (Table ES1). A significant estimate with low quality evidence was found for the outcome of quality of life (Table ES2). All other outcome measures were nonsignificant and supported by low or very low quality of evidence.
Summary of Dichotomous Data
Abbreviations: CI, confidence intervals; COPD, chronic obstructive pulmonary disease; n, number.
Summary of Continuous Data
Abbreviations: CI, confidence intervals; FEV1, forced expiratory volume in 1 second; n, number; SGRQ, St. George’s Respiratory Questionnaire.
PMCID: PMC3384374  PMID: 23074433
16.  Developing an efficient scheduling template of a chemotherapy treatment unit 
The Australasian Medical Journal  2011;4(10):575-588.
This study was undertaken to improve the performance of a Chemotherapy Treatment Unit by increasing the throughput and reducing the average patient’s waiting time. In order to achieve this objective, a scheduling template has been built. The scheduling template is a simple tool that can be used to schedule patients' arrival to the clinic. A simulation model of this system was built and several scenarios, that target match the arrival pattern of the patients and resources availability, were designed and evaluated. After performing detailed analysis, one scenario provide the best system’s performance. A scheduling template has been developed based on this scenario. After implementing the new scheduling template, 22.5% more patients can be served.
Introduction
CancerCare Manitoba is a provincially mandated cancer care agency. It is dedicated to provide quality care to those who have been diagnosed and are living with cancer. MacCharles Chemotherapy unit is specially built to provide chemotherapy treatment to the cancer patients of Winnipeg. In order to maintain an excellent service, it tries to ensure that patients get their treatment in a timely manner. It is challenging to maintain that goal because of the lack of a proper roster, the workload distribution and inefficient resource allotment. In order to maintain the satisfaction of the patients and the healthcare providers, by serving the maximum number of patients in a timely manner, it is necessary to develop an efficient scheduling template that matches the required demand with the availability of resources. This goal can be reached using simulation modelling. Simulation has proven to be an excellent modelling tool. It can be defined as building computer models that represent real world or hypothetical systems, and hence experimenting with these models to study system behaviour under different scenarios.1, 2
A study was undertaken at the Children's Hospital of Eastern Ontario to identify the issues behind the long waiting time of a emergency room.3 A 20-­‐day field observation revealed that the availability of the staff physician and interaction affects the patient wait time. Jyväskylä et al.4 used simulation to test different process scenarios, allocate resources and perform activity-­‐based cost analysis in the Emergency Department (ED) at the Central Hospital. The simulation also supported the study of a new operational method, named "triage-team" method without interrupting the main system. The proposed triage team method categorises the entire patient according to the urgency to see the doctor and allows the patient to complete the necessary test before being seen by the doctor for the first time. The simulation study showed that it will decrease the throughput time of the patient and reduce the utilisation of the specialist and enable the ordering all the tests the patient needs right after arrival, thus quickening the referral to treatment.
Santibáñez et al.5 developed a discrete event simulation model of British Columbia Cancer Agency"s ambulatory care unit which was used to study the impact of scenarios considering different operational factors (delay in starting clinic), appointment schedule (appointment order, appointment adjustment, add-­‐ons to the schedule) and resource allocation. It was found that the best outcomes were obtained when not one but multiple changes were implemented simultaneously. Sepúlveda et al.6 studied the M. D. Anderson Cancer Centre Orlando, which is a cancer treatment facility and built a simulation model to analyse and improve flow process and increase capacity in the main facility. Different scenarios were considered like, transferring laboratory and pharmacy areas, adding an extra blood draw room and applying different scheduling techniques of patients. The study shows that by increasing the number of short-­‐term (four hours or less) patients in the morning could increase chair utilisation.
Discrete event simulation also helps improve a service where staff are ignorant about the behaviour of the system as a whole; which can also be described as a real professional system. Niranjon et al.7 used simulation successfully where they had to face such constraints and lack of accessible data. Carlos et al. 8 used Total quality management and simulation – animation to improve the quality of the emergency room. Simulation was used to cover the key point of the emergency room and animation was used to indicate the areas of opportunity required. This study revealed that a long waiting time, overload personnel and increasing withdrawal rate of patients are caused by the lack of capacity in the emergency room.
Baesler et al.9 developed a methodology for a cancer treatment facility to find stochastically a global optimum point for the control variables. A simulation model generated the output using a goal programming framework for all the objectives involved in the analysis. Later a genetic algorithm was responsible for performing the search for an improved solution. The control variables that were considered in this research are number of treatment chairs, number of drawing blood nurses, laboratory personnel, and pharmacy personnel. Guo et al. 10 presented a simulation framework considering demand for appointment, patient flow logic, distribution of resources, scheduling rules followed by the scheduler. The objective of the study was to develop a scheduling rule which will ensure that 95% of all the appointment requests should be seen within one week after the request is made to increase the level of patient satisfaction and balance the schedule of each doctor to maintain a fine harmony between "busy clinic" and "quiet clinic".
Huschka et al.11 studied a healthcare system which was about to change their facility layout. In this case a simulation model study helped them to design a new healthcare practice by evaluating the change in layout before implementation. Historical data like the arrival rate of the patients, number of patients visited each day, patient flow logic, was used to build the current system model. Later, different scenarios were designed which measured the changes in the current layout and performance.
Wijewickrama et al.12 developed a simulation model to evaluate appointment schedule (AS) for second time consultations and patient appointment sequence (PSEQ) in a multi-­‐facility system. Five different appointment rule (ARULE) were considered: i) Baily; ii) 3Baily; iii) Individual (Ind); iv) two patients at a time (2AtaTime); v) Variable Interval and (V-­‐I) rule. PSEQ is based on type of patients: Appointment patients (APs) and new patients (NPs). The different PSEQ that were studied in this study were: i) first-­‐ come first-­‐serve; ii) appointment patient at the beginning of the clinic (APBEG); iii) new patient at the beginning of the clinic (NPBEG); iv) assigning appointed and new patients in an alternating manner (ALTER); v) assigning a new patient after every five-­‐appointment patients. Also patient no show (0% and 5%) and patient punctuality (PUNCT) (on-­‐time and 10 minutes early) were also considered. The study found that ALTER-­‐Ind. and ALTER5-­‐Ind. performed best on 0% NOSHOW, on-­‐time PUNCT and 5% NOSHOW, on-­‐time PUNCT situation to reduce WT and IT per patient. As NOSHOW created slack time for waiting patients, their WT tends to reduce while IT increases due to unexpected cancellation. Earliness increases congestion whichin turn increases waiting time.
Ramis et al.13 conducted a study of a Medical Imaging Center (MIC) to build a simulation model which was used to improve the patient journey through an imaging centre by reducing the wait time and making better use of the resources. The simulation model also used a Graphic User Interface (GUI) to provide the parameters of the centre, such as arrival rates, distances, processing times, resources and schedule. The simulation was used to measure the waiting time of the patients in different case scenarios. The study found that assigning a common function to the resource personnel could improve the waiting time of the patients.
The objective of this study is to develop an efficient scheduling template that maximises the number of served patients and minimises the average patient's waiting time at the given resources availability. To accomplish this objective, we will build a simulation model which mimics the working conditions of the clinic. Then we will suggest different scenarios of matching the arrival pattern of the patients with the availability of the resources. Full experiments will be performed to evaluate these scenarios. Hence, a simple and practical scheduling template will be built based on the indentified best scenario. The developed simulation model is described in section 2, which consists of a description of the treatment room, and a description of the types of patients and treatment durations. In section 3, different improvement scenarios are described and their analysis is presented in section 4. Section 5 illustrates a scheduling template based on one of the improvement scenarios. Finally, the conclusion and future direction of our work is exhibited in section 6.
Simulation Model
A simulation model represents the actual system and assists in visualising and evaluating the performance of the system under different scenarios without interrupting the actual system. Building a proper simulation model of a system consists of the following steps.
Observing the system to understand the flow of the entities, key players, availability of resources and overall generic framework.
Collecting the data on the number and type of entities, time consumed by the entities at each step of their journey, and availability of resources.
After building the simulation model it is necessary to confirm that the model is valid. This can be done by confirming that each entity flows as it is supposed to and the statistical data generated by the simulation model is similar to the collected data.
Figure 1 shows the patient flow process in the treatment room. On the patient's first appointment, the oncologist comes up with the treatment plan. The treatment time varies according to the patient’s condition, which may be 1 hour to 10 hours. Based on the type of the treatment, the physician or the clinical clerk books an available treatment chair for that time period.
On the day of the appointment, the patient will wait until the booked chair is free. When the chair is free a nurse from that station comes to the patient, verifies the name and date of birth and takes the patient to a treatment chair. Afterwards, the nurse flushes the chemotherapy drug line to the patient's body which takes about five minutes and sets up the treatment. Then the nurse leaves to serve another patient. Chemotherapy treatment lengths vary from less than an hour to 10 hour infusions. At the end of the treatment, the nurse returns, removes the line and notifies the patient about the next appointment date and time which also takes about five minutes. Most of the patients visit the clinic to take care of their PICC line (a peripherally inserted central catheter). A PICC is a line that is used to inject the patient with the chemical. This PICC line should be regularly cleaned, flushed to maintain patency and the insertion site checked for signs of infection. It takes approximately 10–15 minutes to take care of a PICC line by a nurse.
Cancer Care Manitoba provided access to the electronic scheduling system, also known as "ARIA" which is comprehensive information and image management system that aggregates patient data into a fully-­‐electronic medical chart, provided by VARIAN Medical System. This system was used to find out how many patients are booked in every clinic day. It also reveals which chair is used for how many hours. It was necessary to search a patient's history to find out how long the patient spends on which chair. Collecting the snapshot of each patient gives the complete picture of a one day clinic schedule.
The treatment room consists of the following two main limited resources:
Treatment Chairs: Chairs that are used to seat the patients during the treatment.
Nurses: Nurses are required to inject the treatment line into the patient and remove it at the end of the treatment. They also take care of the patients when they feel uncomfortable.
Mc Charles Chemotherapy unit consists of 11 nurses, and 5 stations with the following description:
Station 1: Station 1 has six chairs (numbered 1 to 6) and two nurses. The two nurses work from 8:00 to 16:00.
Station 2: Station 2 has six chairs (7 to 12) and three nurses. Two nurses work from 8:00 to 16:00 and one nurse works from 12:00 to 20:00.
Station 3: Station 4 has six chairs (13 to 18) and two nurses. The two nurses work from 8:00 to 16:00.
Station 4: Station 4 has six chairs (19 to 24) and three nurses. One nurse works from 8:00 to 16:00. Another nurse works from 10:00 to 18:00.
Solarium Station: Solarium Station has six chairs (Solarium Stretcher 1, Solarium Stretcher 2, Isolation, Isolation emergency, Fire Place 1, Fire Place 2). There is only one nurse assigned to this station that works from 12:00 to 20:00. The nurses from other stations can help when need arises.
There is one more nurse known as the "float nurse" who works from 11:00 to 19:00. This nurse can work at any station. Table 1 summarises the working hours of chairs and nurses. All treatment stations start at 8:00 and continue until the assigned nurse for that station completes her shift.
Currently, the clinic uses a scheduling template to assign the patients' appointments. But due to high demand of patient appointment it is not followed any more. We believe that this template can be improved based on the availability of nurses and chairs. Clinic workload was collected from 21 days of field observation. The current scheduling template has 10 types of appointment time slot: 15-­‐minute, 1-­‐hour, 1.5-­‐hour, 2-­‐hour, 3-­‐hour, 4-­‐hour, 5-­‐hour, 6-­‐hour, 8-­‐hour and 10-­‐hour and it is designed to serve 95 patients. But when the scheduling template was compared with the 21 days observations, it was found that the clinic is serving more patients than it is designed for. Therefore, the providers do not usually follow the scheduling template. Indeed they very often break the time slots to accommodate slots that do not exist in the template. Hence, we find that some of the stations are very busy (mostly station 2) and others are underused. If the scheduling template can be improved, it will be possible to bring more patients to the clinic and reduce their waiting time without adding more resources.
In order to build or develop a simulation model of the existing system, it is necessary to collect the following data:
Types of treatment durations.
Numbers of patients in each treatment type.
Arrival pattern of the patients.
Steps that the patients have to go through in their treatment journey and required time of each step.
Using the observations of 2,155 patients over 21 days of historical data, the types of treatment durations and the number of patients in each type were estimated. This data also assisted in determining the arrival rate and the frequency distribution of the patients. The patients were categorised into six types. The percentage of these types and their associated service times distributions are determined too.
ARENA Rockwell Simulation Software (v13) was used to build the simulation model. Entities of the model were tracked to verify that the patients move as intended. The model was run for 30 replications and statistical data was collected to validate the model. The total number of patients that go though the model was compared with the actual number of served patients during the 21 days of observations.
Improvement Scenarios
After verifying and validating the simulation model, different scenarios were designed and analysed to identify the best scenario that can handle more patients and reduces the average patient's waiting time. Based on the clinic observation and discussion with the healthcare providers, the following constraints have been stated:
The stations are filled up with treatment chairs. Therefore, it is literally impossible to fit any more chairs in the clinic. Moreover, the stakeholders are not interested in adding extra chairs.
The stakeholders and the caregivers are not interested in changing the layout of the treatment room.
Given these constraints the options that can be considered to design alternative scenarios are:
Changing the arrival pattern of the patients: that will fit over the nurses' availability.
Changing the nurses' schedule.
Adding one full time nurse at different starting times of the day.
Figure 2 compares the available number of nurses and the number of patients' arrival during different hours of a day. It can be noticed that there is a rapid growth in the arrival of patients (from 13 to 17) between 8:00 to 10:00 even though the clinic has the equal number of nurses during this time period. At 12:00 there is a sudden drop of patient arrival even though there are more available nurses. It is clear that there is an imbalance in the number of available nurses and the number of patient arrivals over different hours of the day. Consequently, balancing the demand (arrival rate of patients) and resources (available number of nurses) will reduce the patients' waiting time and increases the number of served patients. The alternative scenarios that satisfy the above three constraints are listed in Table 2. These scenarios respect the following rules:
Long treatments (between 4hr to 11hr) have to be scheduled early in the morning to avoid working overtime.
Patients of type 1 (15 minutes to 1hr treatment) are the most common. They can be fitted in at any time of the day because they take short treatment time. Hence, it is recommended to bring these patients in at the middle of the day when there are more nurses.
Nurses get tired at the end of the clinic day. Therefore, fewer patients should be scheduled at the late hours of the day.
In Scenario 1, the arrival pattern of the patient was changed so that it can fit with the nurse schedule. This arrival pattern is shown Table 3. Figure 3 shows the new patients' arrival pattern compared with the current arrival pattern. Similar patterns can be developed for the remaining scenarios too.
Analysis of Results
ARENA Rockwell Simulation software (v13) was used to develop the simulation model. There is no warm-­‐up period because the model simulates day-­‐to-­‐day scenarios. The patients of any day are supposed to be served in the same day. The model was run for 30 days (replications) and statistical data was collected to evaluate each scenario. Tables 4 and 5 show the detailed comparison of the system performance between the current scenario and Scenario 1. The results are quite interesting. The average throughput rate of the system has increased from 103 to 125 patients per day. The maximum throughput rate can reach 135 patients. Although the average waiting time has increased, the utilisation of the treatment station has increased by 15.6%. Similar analysis has been performed for the rest of the other scenarios. Due to the space limitation the detailed results are not given. However, Table 6 exhibits a summary of the results and comparison between the different scenarios. Scenario 1 was able to significantly increase the throughput of the system (by 21%) while it still results in an acceptable low average waiting time (13.4 minutes). In addition, it is worth noting that adding a nurse (Scenarios 3, 4, and 5) does not significantly reduce the average wait time or increase the system's throughput. The reason behind this is that when all the chairs are busy, the nurses have to wait until some patients finish the treatment. As a consequence, the other patients have to wait for the commencement of their treatment too. Therefore, hiring a nurse, without adding more chairs, will not reduce the waiting time or increase the throughput of the system. In this case, the only way to increase the throughput of the system is by adjusting the arrival pattern of patients over the nurses' schedule.
Developing a Scheduling Template based on Scenario 1
Scenario 1 provides the best performance. However a scheduling template is necessary for the care provider to book the patients. Therefore, a brief description is provided below on how scheduling the template is developed based on this scenario.
Table 3 gives the number of patients that arrive hourly, following Scenario 1. The distribution of each type of patient is shown in Table 7. This distribution is based on the percentage of each type of patient from the collected data. For example, in between 8:00-­‐9:00, 12 patients will come where 54.85% are of Type 1, 34.55% are of Type 2, 15.163% are of Type 3, 4.32% are of Type 4, 2.58% are of Type 5 and the rest are of Type 6. It is worth noting that, we assume that the patients of each type arrive as a group at the beginning of the hourly time slot. For example, all of the six patients of Type 1 from 8:00 to 9:00 time slot arrive at 8:00.
The numbers of patients from each type is distributed in such a way that it respects all the constraints described in Section 1.3. Most of the patients of the clinic are from type 1, 2 and 3 and they take less amount of treatment time compared with the patients of other types. Therefore, they are distributed all over the day. Patients of type 4, 5 and 6 take a longer treatment time. Hence, they are scheduled at the beginning of the day to avoid overtime. Because patients of type 4, 5 and 6 come at the beginning of the day, most of type 1 and 2 patients come at mid-­‐day (12:00 to 16:00). Another reason to make the treatment room more crowded in between 12:00 to 16:00 is because the clinic has the maximum number of nurses during this time period. Nurses become tired at the end of the clinic which is a reason not to schedule any patient after 19:00.
Based on the patient arrival schedule and nurse availability a scheduling template is built and shown in Figure 4. In order to build the template, if a nurse is available and there are patients waiting for service, a priority list of these patients will be developed. They are prioritised in a descending order based on their estimated slack time and secondarily based on the shortest service time. The secondary rule is used to break the tie if two patients have the same slack. The slack time is calculated using the following equation:
Slack time = Due time - (Arrival time + Treatment time)
Due time is the clinic closing time. To explain how the process works, assume at hour 8:00 (in between 8:00 to 8:15) two patients in station 1 (one 8-­‐hour and one 15-­‐ minute patient), two patients in station 2 (two 12-­‐hour patients), two patients in station 3 (one 2-­‐hour and one 15-­‐ minute patient) and one patient in station 4 (one 3-­‐hour patient) in total seven patients are scheduled. According to Figure 2, there are seven nurses who are available at 8:00 and it takes 15 minutes to set-­‐up a patient. Therefore, it is not possible to schedule more than seven patients in between 8:00 to 8:15 and the current scheduling is also serving seven patients by this time. The rest of the template can be justified similarly.
doi:10.4066/AMJ.2011.837
PMCID: PMC3562880  PMID: 23386870
17.  Primary care satellite clinics and improved access to general and mental health services. 
Health Services Research  2000;35(4):777-790.
OBJECTIVES: To evaluate the relationship between the implementation of community-based primary care clinics and improved access to general health care and/or mental health care, in both the general population and among people with disabling mental illness. STUDY SETTING: The 69 new community-based primary care clinics in underserved areas, established by the Department of Veterans Affairs (VA) between the last quarter of FY 1995 and the second quarter of FY 1998, including the 21 new clinics with a specialty mental health care component. DATA SOURCES: VA inpatient and outpatient workload files, 1990 U.S. Census data, and VA Compensation and Pension files were used to determine the proportion of all veterans, and the proportion of disabled veterans, living in each U.S. county who used VA general health care services and VA mental health services before and after these clinics began operation. DESIGN: Analysis of covariance was used to compare changes, from late FY 1995 through early FY 1998, in access to VA services in counties in which new primary care clinics were located, in counties in which clinics that included specialized mental health components were located, and for comparison, in other U.S. counties, adjusting for potentially confounding factors. KEY FINDINGS: Counties in which new clinics were located showed a significant increase from the FY 1995-FY 1998 study dates in the proportion of veterans who used general VA health care services. This increase was almost twice as large as that observed in comparison counties (4.2% vs. 2.5%: F = 12.6, df = 1,3118, p = .0004). However, the introduction of these clinics was not associated with a greater use of specialty VA mental health services in the general veteran population, or of either general health care services or mental health services among veterans who received VA compensation for psychiatric disorders. In contrast, in counties with new clinics that included a mental health component the proportion of veterans who used VA mental health services increased to almost three times the proportion in comparison counties (0.87% vs. 0.31%: F = 8.3, df = 1,3091, p = .004). CONCLUSIONS: Community-based primary care clinics can improve access to general health care services, but a specialty mental health care component appears to be needed to improve access to mental health services.
PMCID: PMC1089152  PMID: 11055448
18.  Continuity in a VA Patient-Centered Medical Home Reduces Emergency Department Visits 
PLoS ONE  2014;9(5):e96356.
Background
One major goal of the Patient-Centered Medical Home (PCMH) is to improve continuity of care between patients and providers and reduce the utilization of non-primary care services like the emergency department (ED).
Objective
To characterize continuity under the Veterans Health Administration’s PCMH model – the Patient Aligned Care Team (PACT), at one large Veterans Affair’s (VA’s) primary care clinic, determine the characteristics associated with high levels of continuity, and assess the association between continuity and ED visits.
Design
Retrospective, observational cohort study of patients at the West Haven VA (WHVA) Primary Care Clinic from March 2011 to February 2012.
Patients
The 13,495 patients with established care at the Clinic, having at least one visit, one year before March 2011.
Main Measures
Our exposure variable was continuity of care –a patient seeing their assigned primary care provider (PCP) at each clinic visit. The outcome of interest was having an ED visit.
Results
The patients encompassed 42,969 total clinic visits, and 3185 (24%) of them had 15,458 ED visits. In a multivariable logistic regression analysis, patients with continuity of care – at least one visit with their assigned PCP – had lower ED utilization compared to individuals without continuity (adjusted odds ratio [AOR] 0.54; 95% CI: 0.41, 0.71), controlling for frequency of primary care visits, comorbidities, insurance, distance from the ED, and having a trainee PCP assigned. Likewise, the adjusted rate of ED visits was 544/1000 person-year (PY) for patients with continuity vs. 784/1000 PY for patients without continuity (p = 0.001). Compared to patients with low continuity (<33% of visits), individuals with medium (33–50%) and high (>50%) continuity were less likely to utilize the ED.
Conclusions
Strong continuity of care is associated with decreased ED utilization in a PCMH model and improving continuity may help reduce the utilization of non-primary care services.
doi:10.1371/journal.pone.0096356
PMCID: PMC4035271  PMID: 24867300
19.  Longitudinal Approaches to Evaluate Health Care Quality and Outcomes: The Veterans Health Administration Diabetes Epidemiology Cohorts 
Objective
The Institute of Medicine proposed recently that, while current pay for performance measures should target multiple dimensions of care, including measures of technical quality, they should transition toward longitudinal and health-outcome measures across systems of care. This article describes the development of the Diabetes Epidemiology Cohorts (DEpiC), which facilitates evaluation of intermediate “quality of care” outcomes and surveillance of adverse outcomes for veterans with diabetes served by the Veterans Health Administration (VHA) over multiple years.
Methods
The Diabetes Epidemiology Cohorts is a longitudinal research database containing records for all diabetes patients in the VHA since 1998. It is constructed using data from a variety of national computerized data files in the VHA (including medical encounters, prescriptions, laboratory tests, and mortality files), Medicare claims data for VHA patients, and large patient surveys conducted by the VHA. Rigorous methodology is applied in linking and processing data into longitudinal patient records to assure data quality.
Results
Validity is demonstrated in the construction of the DEpiC. Adjusted comparisons of disease prevalence with general population estimates are made. Further analyses of intermediate outcomes of care demonstrate the utility of the database. In the first example, using growth curve models, we demonstrated that hemoglobin A1c trends exhibit marked seasonality and that serial cross-sectional outcomes overestimate the improvement in population A1c levels compared to longitudinal cohort evaluation. In the second example, the use of individual level data enabled the mapping of regional performance in amputation prevention into four quadrants using calculated observed to expected major and minor amputation rates. Simultaneous evaluation of outliers in all categories of amputation may improve the oversight of foot care surveillance programs.
Conclusions
The use of linked, patient level longitudinal data resolves confounding case mix issues inherent in the use of serial cross-sectional data. Policy makers should be aware of the limitations of cross-sectional data and should make use of longitudinal patient databases to evaluate clinical outcomes.
PMCID: PMC2769712  PMID: 19885174
A1c; amputations; databases; diabetes; registry
20.  Assessing the quality of healthcare provided to children. 
Health Services Research  1998;33(4 Pt 2):1059-1090.
OBJECTIVE: To present a conceptual framework for evaluating quality of care for children and adolescents, summarize the key issues related to developing measures to assess pediatric quality of care, examine some existing measures, and present evidence about their current level of performance. PRINCIPAL FINDINGS: Assessing the quality of care for children poses many challenges not encountered when making these measurements in the adult population. Children and adolescents (from this point forward referred to collectively as children unless differentiation is necessary) differ from adults in two clinically important ways (Jameson and Wehr 1993): (1) their normal developmental trajectory is characterized by change, and (2) they have differential morbidity. These factors contribute to the limitations encountered when developing measures to assess the quality of care for children. The movement of a child through the various stages of development makes it difficult to establish what constitutes a "normal" outcome and by extension what constitutes a poor outcome. Additionally, salient developmental outcomes that result from poor quality of care may not be observed for several years. This implies that poor outcomes may be observed when the child is receiving care from a delivery system other than the one that provided the low-quality care. Attributing the suboptimal outcome to the new delivery system would be inappropriate. Differential morbidity refers to the fact that the type, prevalence, and severity of illness experienced by children is measurably different from that observed in adults. Most children experience numerous self-limited illness of mild severity. A minority of children suffer from markedly more severe diseases. Thus, condition-specific measures in children are problematic to implement for routine assessments because of the extremely low incidence and prevalence of most severe pediatric diseases (Halfon 1996). However, children with these conditions are potentially the segment of the pediatric population that can be most affected by variations in the quality of care. Improving the care provided to these children is likely to have the largest impact on quality of life and longevity. The low prevalence of most severe pediatric diseases also makes it difficult to evaluate the effectiveness of new treatment modalities; multi-center trials or long enrollment periods are usually required to obtain a large enough patient sample to conduct the necessary randomized controlled trials or cohort studies. Another challenge encountered when measuring quality of care for children is that, in most cases, they depend on adults to both obtain care and to report on the outcomes of that care. Parents and their children may have different perceptions of what defines health or have different levels of satisfaction with the care they receive. Children, particularly those with special needs, also depend on a broad range of services including the medical system, community intervention programs, social programs, and school-based services. Dependency on these various services adds to the difficulty of measuring and appropriately attributing health outcomes observed in children to a particular service delivery entity. Adolescents also depend on adults for access to some of their care; however, they have special needs related to confidentiality and parent-child information sharing. Adolescents commonly seek care at facilities, such as school-based clinics, that allow them to obtain confidential care. These facilities usually provide out-of-health plan care for these children, which raises special issues related to information availability for quality assessments and for assessing utilization patterns in this population. If the source of poor health outcomes is not known, quality improvement is not possible. The many challenges faced when constructing pediatric (this term will be used to refer to both children and adolescents) quality of care measures have resulted in few of these instruments being developed specifically for children. Most of the measures developed to date have either a very limited pediatric component or still require the process or outcome validation step. Although several practice guidelines and indicators of quality have been constructed, a conceptual framework to guide the development of such tools for quality assessment in the pediatric population is lacking. CONCLUSIONS. Pediatric health services researchers and the organizations that fund this work need to focus on developing a set of quality assessment tools that will address several challenging issues. Working within the context of the conceptual framework presented, we draw several conclusions related to issues that should be considered in developing quality of care measures for children.
PMCID: PMC1070304  PMID: 9776949
21.  A Systematic Review and Meta-Analysis of Utility-Based Quality of Life in Chronic Kidney Disease Treatments 
PLoS Medicine  2012;9(9):e1001307.
Melanie Wyld and colleagues examined previously published studies to assess pooled utility-based quality of life of the various treatments for chronic kidney disease. They conclude that the highest utility was for kidney transplants, with home-based automated peritoneal dialysis being second.
Background
Chronic kidney disease (CKD) is a common and costly condition to treat. Economic evaluations of health care often incorporate patient preferences for health outcomes using utilities. The objective of this study was to determine pooled utility-based quality of life (the numerical value attached to the strength of an individual's preference for a specific health outcome) by CKD treatment modality.
Methods and Findings
We conducted a systematic review, meta-analysis, and meta-regression of peer-reviewed published articles and of PhD dissertations published through 1 December 2010 that reported utility-based quality of life (utility) for adults with late-stage CKD. Studies reporting utilities by proxy (e.g., reported by a patient's doctor or family member) were excluded.
In total, 190 studies reporting 326 utilities from over 56,000 patients were analysed. There were 25 utilities from pre-treatment CKD patients, 226 from dialysis patients (haemodialysis, n = 163; peritoneal dialysis, n = 44), 66 from kidney transplant patients, and three from patients treated with non-dialytic conservative care. Using time tradeoff as a referent instrument, kidney transplant recipients had a mean utility of 0.82 (95% CI: 0.74, 0.90). The mean utility was comparable in pre-treatment CKD patients (difference = −0.02; 95% CI: −0.09, 0.04), 0.11 lower in dialysis patients (95% CI: −0.15, −0.08), and 0.2 lower in conservative care patients (95% CI: −0.38, −0.01). Patients treated with automated peritoneal dialysis had a significantly higher mean utility (0.80) than those on continuous ambulatory peritoneal dialysis (0.72; p = 0.02). The mean utility of transplant patients increased over time, from 0.66 in the 1980s to 0.85 in the 2000s, an increase of 0.19 (95% CI: 0.11, 0.26). Utility varied by elicitation instrument, with standard gamble producing the highest estimates, and the SF-6D by Brazier et al., University of Sheffield, producing the lowest estimates. The main limitations of this study were that treatment assignments were not random, that only transplant had longitudinal data available, and that we calculated EuroQol Group EQ-5D scores from SF-36 and SF-12 health survey data, and therefore the algorithms may not reflect EQ-5D scores measured directly.
Conclusions
For patients with late-stage CKD, treatment with dialysis is associated with a significant decrement in quality of life compared to treatment with kidney transplantation. These findings provide evidence-based utility estimates to inform economic evaluations of kidney therapies, useful for policy makers and in individual treatment discussions with CKD patients.
Editors' Summary
Background
Ill health can adversely affect an individual's quality of life, particularly if caused by long-term (chronic) conditions, such as chronic kidney disease—in the United States alone, 23 million people have chronic kidney disease, of whom 570,000 are treated with dialysis or kidney transplantation. In order to measure the cost-effectiveness of interventions to manage medical conditions, health economists use an objective measurement known as quality-adjusted life years. However, although useful, quality-adjusted life years are often criticized for not taking into account the views and preferences of the individuals with the medical conditions. A measurement called a utility solves this problem. Utilities are a numerical value (measured on a 0 to 1 scale, where 0 represents death and 1 represents full health) of the strength of an individual's preference for specified health-related outcomes, as measured by “instruments” (questionnaires) that rate direct comparisons or assess quality of life.
Why Was This Study Done?
Previous studies have suggested that, in people with chronic kidney disease, quality of life (as measured by utility) is higher in those with a functioning kidney transplant than in those on dialysis. However, currently, it is unclear whether the type of dialysis affects quality of life: hemodialysis is a highly technical process that directly filters the blood, usually must be done 2–4 times a week, and can only be performed in a health facility; peritoneal dialysis, in which fluids are infused into the abdominal cavity, can be done nightly at home (automated peritoneal dialysis) or throughout the day (continuous ambulatory peritoneal dialysis). In this study, the researchers reviewed and assimilated all of the available evidence to investigate whether quality of life in people with chronic kidney disease (as measured by utility) differed according to treatment type.
What Did the Researchers Do and Find?
The researchers did a comprehensive search of 11 databases to identify all relevant studies that included people with severe (stage 3, 4, or 5) chronic kidney disease, their form of treatment, and information on utilities—either reported directly, or included in quality of life instruments (SF-36), so the researchers could calculate utilities by using a validated algorithm. The researchers also recorded the prevalence rates of diabetes in study participants. Then, using statistical models that adjusted for various factors, including treatment type and the method of measuring utilities, the researchers were able to calculate the pooled utilities of each form of treatment for chronic kidney disease.
The researchers included 190 studies, representing over 56,000 patients and generating 326 utility estimates, in their analysis. The majority of utilities (77%) were derived through the SF-36 questionnaire via calculation. Of the 326 utility estimates, 25 were from patients pre-dialysis, 226 were from dialysis patients (the majority of whom were receiving hemodialysis), 66 were from kidney transplant patients, and three were from conservative care patients. The researchers found that the highest average utility was for those who had renal transplantation, 0.82, followed by the pre-dialysis group (0.80), dialysis patients (0.71), and, finally, patients receiving conservative care (0.62). When comparing the type of dialysis, the researchers found that there was little difference in utility between hemodialysis and peritoneal dialysis, but patients using automated peritoneal dialysis had, on average, a higher utility (0.80) than those treated with continuous ambulatory peritoneal dialysis (0.72). Finally, the researchers found that patient groups with diabetes had significantly lower utilities than those without diabetes.
What Do These Findings Mean?
These findings suggest that in people with chronic kidney disease, renal transplantation is the best treatment option to improve quality of life. For those on dialysis, home-based automated peritoneal dialysis may improve quality of life more than the other forms of dialysis: this finding is important, as this type of dialysis is not as widely used as other forms and is also cheaper than hemodialysis. Furthermore, these findings suggest that patients who choose conservative care have significantly lower quality of life than patients treated with dialysis, a finding that warrants further investigation. Overall, in addition to helping to inform economic evaluations of treatment options, the information from this analysis can help guide clinicians caring for patients with chronic kidney disease in their discussions about possible treatment options.
Additional Information
Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001307.
Information about chronic kidney disease is available from the National Kidney Foundation and MedlinePlus
Wikipedia gives information on general utilities (note that Wikipedia is a free online encyclopedia that anyone can edit; available in several languages)
doi:10.1371/journal.pmed.1001307
PMCID: PMC3439392  PMID: 22984353
22.  Differences in rehabilitation services and outcomes among stroke patients cared for in veterans hospitals. 
Health Services Research  2001;35(6):1293-1318.
OBJECTIVE: To examine the relationship of services for post-acute care (PAC) to stroke patient outcomes. DATA SOURCES/STUDY SETTING: Veterans Health Administration (VHA) hospitals from two facility-level surveys and extant data files. STUDY DESIGN: Cross-sectional study of veterans hospitalized with acute stroke during the period June 1995 through May 1996 in one of 182 geographically distinct locations within the VHA. Study variables included (1) a typological classification of hospitals according to the level of PAC; (2) a taxonomy of rehabilitation characteristics, including personnel, physical facilities, coordination of care, and hospital characteristics; and (3) patient outcomes (discharge destination, length of stay). DATA COLLECTION/EXTRACTION METHODS: Data were collected from two mailed surveys and extant data files. Rehabilitation variables were identified for the study in conjunction with a panel of expert rehabilitation researchers and clinicians, using an a priori model for measuring rehabilitation characteristics. Two sets of variables were derived to categorize these rehabilitation characteristics: (1) a rehabilitation typology, classifying the VA hospitals according to the continuum of PAC settings in the facility, and (2) a rehabilitation taxonomy that used an empirical approach to derive a list of key rehabilitation characteristics. PRINCIPAL FINDINGS: Twenty-seven percent of veterans with acute stroke were cared for in VA hospitals with neither a geriatric nor a rehabilitation unit, and 50 percent were cared for in hospitals without a rehabilitation unit. Hospitals with rehabilitation units had the greatest sophistication, and those with geriatric units had intermediate sophistication in rehabilitation organization and resources. Statistically significant differences were found in outcomes for stroke patients cared for in hospitals classified according to the continuum of post-acute care on site. Exploratory multivariable analyses revealed independent associations between stroke patient outcomes and (1) staffing ratios for nurses and physicians, (2) the diversity of physician and rehabilitation staff, (3) presence of a simulated home environment, and (4) the total number of care settings on site. CONCLUSIONS: The PAC continuum defines an important hierarchy of stroke rehabilitation services.
PMCID: PMC1089191  PMID: 11221820
23.  Associations between Stroke Mortality and Weekend Working by Stroke Specialist Physicians and Registered Nurses: Prospective Multicentre Cohort Study 
PLoS Medicine  2014;11(8):e1001705.
In a multicenter observational study, Benjamin Bray and colleagues evaluate whether weekend rounds by stroke specialist physicians, or the ratio of registered nurses to beds on weekends, is associated with patient mortality after stroke.
Please see later in the article for the Editors' Summary
Background
Observational studies have reported higher mortality for patients admitted on weekends. It is not known whether this “weekend effect” is modified by clinical staffing levels on weekends. We aimed to test the hypotheses that rounds by stroke specialist physicians 7 d per week and the ratio of registered nurses to beds on weekends are associated with mortality after stroke.
Methods and Findings
We conducted a prospective cohort study of 103 stroke units (SUs) in England. Data of 56,666 patients with stroke admitted between 1 June 2011 and 1 December 2012 were extracted from a national register of stroke care in England. SU characteristics and staffing levels were derived from cross-sectional survey. Cox proportional hazards models were used to estimate hazard ratios (HRs) of 30-d post-admission mortality, adjusting for case mix, organisational, staffing, and care quality variables. After adjusting for confounders, there was no significant difference in mortality risk for patients admitted to a stroke service with stroke specialist physician rounds fewer than 7 d per week (adjusted HR [aHR] 1.04, 95% CI 0.91–1.18) compared to patients admitted to a service with rounds 7 d per week. There was a dose–response relationship between weekend nurse/bed ratios and mortality risk, with the highest risk of death observed in stroke services with the lowest nurse/bed ratios. In multivariable analysis, patients admitted on a weekend to a SU with 1.5 nurses/ten beds had an estimated adjusted 30-d mortality risk of 15.2% (aHR 1.18, 95% CI 1.07–1.29) compared to 11.2% for patients admitted to a unit with 3.0 nurses/ten beds (aHR 0.85, 95% CI 0.77–0.93), equivalent to one excess death per 25 admissions. The main limitation is the risk of confounding from unmeasured characteristics of stroke services.
Conclusions
Mortality outcomes after stroke are associated with the intensity of weekend staffing by registered nurses but not 7-d/wk ward rounds by stroke specialist physicians. The findings have implications for quality improvement and resource allocation in stroke care.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
In a perfect world, a patient admitted to hospital on a weekend or during the night should have as good an outcome as a patient admitted during regular working hours. But several observational studies (investigations that record patient outcomes without intervening in any way; clinical trials, by contrast, test potential healthcare interventions by comparing the outcomes of patients who are deliberately given different treatments) have reported that admission on weekends is associated with a higher mortality (death) rate than admission on weekdays. This “weekend effect” has led to calls for increased medical and nursing staff to be available in hospitals during the weekend and overnight to ensure that the healthcare provided at these times is of equal quality to that provided during regular working hours. In the UK, for example, “seven-day working” has been identified as a policy and service improvement priority for the National Health Service.
Why Was This Study Done?
Few studies have actually tested the relationship between patient outcomes and weekend physician or nurse staffing levels. It could be that patients who are admitted to hospital on the weekend have poor outcomes because they are generally more ill than those admitted on weekdays. Before any health system introduces potentially expensive increases in weekend staffing levels, better evidence that this intervention will improve patient outcomes is needed. In this prospective cohort study (a study that compares the outcomes of groups of people with different baseline characteristics), the researchers ask whether mortality after stroke is associated with weekend working by stroke specialist physicians and registered nurses. Stroke occurs when the brain's blood supply is interrupted by a blood vessel in the brain bursting (hemorrhagic stroke) or being blocked by a blood clot (ischemic stroke). Swift treatment can limit the damage to the brain caused by stroke, but of the 15 million people who have a stroke every year, about 6 million die within a few hours and another 5 million are left disabled.
What Did the Researchers Do and Find?
The researchers extracted clinical data on 56,666 patients who were admitted to stroke units in England over an 18-month period from a national stroke register. They obtained information on the characteristics and staffing levels of the stroke units from a biennial survey of hospitals admitting patients with stroke, and information on deaths among patients with stroke from the national register of deaths. A quarter of the patients were admitted on a weekend, almost half the stroke units provided stroke specialist physician rounds seven days per week, and the remainder provided rounds five days per week. After adjustment for factors that might have affected outcomes (“confounders”) such as stroke severity and the level of acute stroke care available in each stroke unit, there was no significant difference in mortality risk between patients admitted to a stroke unit with rounds seven days/week and patients admitted to a unit with rounds fewer than seven days/week. However, patients admitted on a weekend to a stroke unit with 1.5 nurses/ten beds had a 30-day mortality risk of 15.2%, whereas patients admitted to a unit with 3.0 nurses/ten beds had a mortality risk of 11.2%, a mortality risk difference equivalent to one excess death per 25 admissions.
What Do These Findings Mean?
These findings show that the provision of stroke specialist physician rounds seven days/week in stroke units in England did not influence the (weak) association between weekend admission for stroke and death recorded in this study, but mortality outcomes after stroke were associated with the intensity of weekend staffing by registered nurses. The accuracy of these findings may be affected by the measure used to judge the level of acute care available in each stroke unit and by residual confounding. For example, patients admitted to units with lower nursing levels may have shared other unknown characteristics that increased their risk of dying after stroke. Moreover, this study considered the impact of staffing levels on mortality only and did not consider other relevant outcomes such as long-term disability. Despite these limitations, these findings support the provision of higher weekend ratios of registered nurses to beds in stroke units, but given the high costs of increasing weekend staffing levels, it is important that controlled trials of different models of physician and nursing staffing are undertaken as soon as possible.
Additional Information
Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001705.
This study is further discussed in a PLOS Medicine Perspective by Meeta Kerlin
Information about plans to introduce seven-day working into the National Health Service in England is available; the 2013 publication “NHS Services—Open Seven Days a Week: Every Day Counts” provides examples of how hospitals across England are working together to provide routine healthcare services seven days a week; a “Behind the Headlines” article on the UK National Health Service Choices website describes a recent observational study that investigated the association between admission to hospital on the weekend and death, and newspaper coverage of the study's results; the Choices website also provides information about stroke for patients and their families, including personal stories
A US nurses' site includes information on the association of nurse staffing with patient safety
The US National Institute of Neurological Disorders and Stroke provides information about all aspects of stroke (in English and Spanish); its Know Stroke site provides educational materials about stroke prevention, treatment, and rehabilitation, including personal stories (in English and Spanish); the US National Institute of Health SeniorHealth website has additional information about stroke
The Internet Stroke Center provides detailed information about stroke for patients, families, and health professionals (in English and Spanish)
doi:10.1371/journal.pmed.1001705
PMCID: PMC4138029  PMID: 25137386
24.  Time-Dependent Prediction and Evaluation of Variable Importance Using SuperLearning in High Dimensional Clinical Data 
Background
Prediction of outcome after injury is fraught with uncertainty and statistically beset by misspecified models. Single-time point regression only gives prediction and inference at one time, of dubious value for continuous prediction of ongoing bleeding. New statistical, machine learning techniques such as SuperLearner exist to make superior prediction at iterative time-points while also evaluating the changing relative importance of each measured variable on an outcome. This then can provide continuously changing prediction of outcome and evaluation of which clinical variables likely drive a particular outcome.
Methods
PROMMTT data was evaluated utilizing both naïve (standard stepwise logistic regression) and SuperLearner techniques to develop a time-dependent prediction of future mortality, within discrete time intervals. We avoided both under- and over-fitting using cross-validation to select an optimal combination of predictors among candidate predictors/machine learning algorithms. SuperLearner was also used to produce interval-specific robust measures of variable importance measures (VIM resulting in an ordered list of variables, by time-point) that have the strongest impact on future mortality.
Results
980 patients had complete clinical and outcome data and were included in the analysis. The prediction of ongoing transfusion with SuperLearner was superior to the naïve approach for all time intervals (correlations of cross-validated predictions with the outcome were 0.819, 0.789, 0.792 for time intervals 30–90, 90–180, 180–360, >360 minutes. The estimated VIM of mortality also changed significantly at each time point
Conclusions
The SuperLeaner technique for prediction of outcome from a complex dynamic multivariate dataset is superior at each time interval to standard models. Additionally, the SuperLearner VIM at each time point provides insight into the time-specific drivers of future outcome, patient trajectory and targets for clinical intervention. Thus, this automated approach mimics clinical practice, changing form and content through time to optimize the accuracy of the prognosis based on the evolving trajectory of the patient.
Level of Evidence
Prospective, Level II
doi:10.1097/TA.0b013e3182914553
PMCID: PMC3744063  PMID: 23778512
PROMMTT; Trauma; Injury; Statistical Prediction; Causal Inference
25.  Modeling Relations Among Discrete Developmental Processes: A General Approach to Associative Latent Transition Analysis 
To understand one developmental process, it is often helpful to investigate its relations with other developmental processes. Statistical methods that model development in multiple processes simultaneously over time include latent growth curve models with time-varying covariates, multivariate latent growth curve models, and dual trajectory models. These models are designed for growth represented by continuous, unidimensional trajectories. The purpose of this article is to present a flexible approach to modeling relations in development among two or more discrete, multidimensional latent variables based on the general framework of loglinear modeling with latent variables called associative latent transition analysis (ALTA). Focus is given to the substantive interpretation of different associative latent transition models, and exactly what hypotheses are expressed in each model. An empirical demonstration of ALTA is presented to examine the association between the development of alcohol use and sexual risk behavior during adolescence.
doi:10.1080/10705511.2010.510043
PMCID: PMC3094019  PMID: 21572599
latent class analysis; latent transition analysis; associative latent transition analysis; loglinear modeling; sexual behavior; alcohol use; adolescents

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