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1.  Public Payments to Physicians in Ontario Adjusted for Overhead Costs 
Healthcare Policy  2012;8(2):30-36.
We used data collected in the 2010 National Physician Survey and public payment data published in the Institute for Clinical and Evaluative Sciences report Payments to Ontario Physicians from Ministry of Health and Long-Term Care Sources 1992/93 to 2009/10 to estimate 2009/2010 net physician income from public payments for Ontario physicians by specialty. Incorporating overhead substantially affects estimates of physician income and changes relative position. For example, ophthalmologists were ranked second when only public payments were considered but eighth when overhead was included. Conversely, hospital-based specialties such as anaesthesia, radiation oncology and emergency medicine rank significantly higher after overhead is included.
PMCID: PMC3517870  PMID: 23968613
2.  Impact of provider volume on operative mortality after radical cystectomy in a publicly funded healthcare system 
Introduction:
We assess the effect of cystectomy provider volume on postoperative mortality in a publicly funded healthcare system. Hospital and surgeon (provider) volume have been shown to be associated with clinically important outcomes for many types of surgery. Volume-outcome studies in patients undergoing radical cystectomy for bladder cancer have primarily originated from privately funded healthcare systems.
Methods:
We identified patients undergoing cystectomy in Ontario, Canada, between 1992 and 2004 using administrative databases. The effect of provider volume on postoperative mortality was assessed with multilevel (hierarchical or random effects) logistic regression models, adjusted for patient characteristics. Separate models were fit to examine the effect of surgeon volume and the effect of hospital volume.
Results:
Of the 3296 cystectomy patients identified, 126 (3.8%) experienced a postoperative death. Neither hospital volume (odds ratio [per 1 unit increase in volume] 0.98, 95% confidence interval [CI] 0.95–1.00; p = 0.074) nor surgeon volume (odds ratio 0.96, 95% CI 0.90–1.02; p = 0.143) were statistically significantly associated with postoperative cystectomy mortality.
Conclusions:
In Ontario’s publicly funded healthcare system, provider volume was not significantly associated with postoperative mortality.
doi:10.5489/cuaj.361
PMCID: PMC3876442  PMID: 24381661
3.  What do letters to the editor publish about randomized controlled trials? A cross-sectional study 
BMC Research Notes  2013;6:414.
Background
To identify published letters to the editor (LTE) written in response to randomized controlled trials (RCTs), determine the topics addressed in the letters, and to examine if these topics were affected by the characteristics and results of the RCTs.
Methods
Comparative cross-sectional study of a representative sample of RCTs from a set of high-impact medical journals (BMJ, Lancet, NEJM, JAMA, and Annals of Internal Medicine). RCTs and their published LTE were searched from these 5 journals in 2007. Data were collected on RCTs and their characteristics (author affiliation, funding source, intervention, and effect on the primary outcome) and the topics addressed in published LTE related to these RCTs. Analysis included chi-square and regression analysis (RCT characteristics) and thematic analysis (LTE topics).
Results
Of 334 identified RCTs, 175 trials had at least one LTE. Of these, 381 published LTE were identified. Most RCTs, tested drug interventions (68%), were funded by government (54%) or industry (33%), and described an intervention that had a positive impact on the primary outcome (62%). RCT authors were primarily affiliated with an academic centre (78%). Ninety percent of the 623 LTE topics concerned methodological issues regarding the analysis, intervention, and population in the RCT. There was a significant association between funding source and impact on outcomes (p = 0.002) or type of intervention tested (p = 0.001) in these trials. Clinical and “Other” LTE topics were more likely to be published in response to a government funded RCT (p = 0.005 and p = 0.033, respectively); no other comparisons were significant.
Conclusions
This study showed that most LTE are about methodological topics, but found little evidence to support that these topics are affected by the characteristics or results of the RCTs. The lack of association may be explained by editorial censorship as a small proportion of LTE that are submitted are actually published.
doi:10.1186/1756-0500-6-414
PMCID: PMC3852599  PMID: 24124753
Letters to the editor; Randomized controlled trials; Journalogy
4.  The Average Lifespan of Patients Discharged from Hospital with Heart Failure 
Journal of General Internal Medicine  2012;27(9):1171-1179.
ABSTRACT
BACKGROUND
There are no life-tables quantifying the average life-spans of post-hospitalized heart failure populations across various strata of risk.
OBJECTIVE
To quantify the life-expectancies (i.e., average life-spans) of heart failure patients at the time of hospital discharge according to age, gender, predictive 30-day mortality heart failure risk index, and comorbidity burden.
DESIGN
Population-based retrospective cohort study.
SETTING
Ontario, Canada.
PATIENTS
7,865 heart failure patients discharged from Ontario hospitals between 1999 and 2000.
MEASUREMENTS
Data were obtained from the Enhanced Feedback for Effective Cardiac Treatment EFFECT provincial quality improvement initiative. All patients were linked to administrative data, and tracked longitudinally until March 31, 2010. Detailed clinical variables were obtained from medical chart abstraction, and death data were obtained from vital statistics. Average life-spans were calculated using Cox Proportion Hazards models in conjunction with the Declining Exponential Approximation of Life Expectancy (D.E.A.L.E) method to extrapolate life-expectancy, adjusting for age, gender, predicted 30-day mortality, left ventricular function and comorbidity, and was reported according to key prognostic risk-strata.
RESULTS
The average life-span of the cohort was 5.5 years (STD +/− 10.0) ranging from 19.5 years for low-risk women of less than 50 years old to 2.9 years for high-risk octogenarian males. Average life-spans were lower by 0.13 years among patients with impaired as compared with preserved left ventricular function, and by approximately one year among patients with three or more as compared with no concomitant comorbidities. In total, 17.4 % and 27 % of patients had died within 6 months and 1 year respectively, despite having predicted life-spans exceeding one-year.
LIMITATIONS
Data regarding changes in patient clinical status over time were unavailable.
CONCLUSIONS
The development of risk-adjusted life-tables for heart failure populations is feasible and mirrored those with advanced malignant diseases. Average life span varied widely across clinical risk strata, and may be less accurate among those at or near their end of life.
doi:10.1007/s11606-012-2072-y
PMCID: PMC3515002  PMID: 22549300
life-expectancy; heart failure; risk; survival; comorbidity
5.  The Timing of Drug Funding Announcements Relative to Elections: A Case Study Involving Dementia Medications 
PLoS ONE  2013;8(2):e56921.
Background
Following initial regulatory approval of prescription drugs, many factors may influence insurers and health systems when they decide whether to add these drugs to their formularies. The role of political pressures on drug funding announcements has received relatively little attention, and elections represent an especially powerful form of political pressure. We examined the temporal relationship between decisions to add one class of drugs to publicly funded formularies in Canada's ten provinces and elections in these jurisdictions.
Methods
Dates of provincial formulary listings for cholinesterase inhibitors, which are drugs used to treat Alzheimer's disease and related dementias, were compared to the dates of provincial elections. Medical journal articles, media reports, and proceedings from provincial legislatures were reviewed to assemble information on the chronology of events. We tested whether there was a statistically significant increase in the probability of drug funding announcements within the 60-day intervals preceding provincial elections.
Results
Decisions to fund the cholinesterase inhibitors were made over a nine-year span from 1999 to 2007 in the ten provinces. In four of ten provinces, the drugs were added to formularies in a time period closely preceding a provincial election (P = 0.032); funding announcements in these provinces were made between 2 and 47 days prior to elections. Statements made in provincial legislatures highlight the key role of political pressures in these funding announcements.
Conclusions
Impending elections appeared to affect the timing of drug funding announcements in this case study. Despite an established structure for evidence-based decision-making, drug funding remains a complex process open to influence from many sources. Awareness of such influences is critical to maintain effective drug policy and public health decision-making.
doi:10.1371/journal.pone.0056921
PMCID: PMC3584056  PMID: 23460820
6.  Designing and evaluating a web-based self-management site for patients with type 2 diabetes - systematic website development and study protocol 
Background
Given that patients provide the majority of their own diabetes care, patient self-management training has increasingly become recognized as an important strategy with which to improve quality of care. However, participation in self management programs is low. In addition, the efficacy of current behavioural interventions wanes over time, reducing the impact of self-management interventions on patient health. Web-based interventions have the potential to bridge the gaps in diabetes care and self-management.
Methods
Our objective is to improve self-efficacy, quality of life, self-care, blood pressure, cholesterol and glycemic control and promote exercise in people with type 2 diabetes through the rigorous development and use of a web-based patient self-management intervention. This study consists of five phases: (1) intervention development; (2) feasibility testing; (3) usability testing; (4) intervention refinement; and (5) intervention evaluation using mixed methods. We will employ evidence-based strategies and tools, using a theoretical framework of self-efficacy, then elicit user feedback through focus groups and individual user testing sessions. Using iterative redesign the intervention will be refined. Once finalized, the impact of the website on patient self-efficacy, quality of life, self-care, HbA1c, LDL-cholesterol, blood pressure and weight will be assessed through a non-randomized observational cohort study using repeated measures modeling and individual interviews.
Discussion
Increasing use of the World Wide Web by consumers for health information and ongoing revolutions in social media are strong indicators that users are primed to welcome a new era of technology in health care. However, their full potential is hindered by limited knowledge regarding their effectiveness, poor usability, and high attrition rates. Our development and research agenda aims to address these limitations by improving usability, identifying characteristics associated with website use and attrition, and developing strategies to sustain patient use in order to maximize clinical outcomes.
doi:10.1186/1472-6947-12-57
PMCID: PMC3473319  PMID: 22726578
Diabetes mellitus; Self care; Patient education; Self-efficacy; Medical informatics; Intervention development; Study protocol; User-Computer Interface; Repeated measures modeling; Qualitative methods
7.  Enrolment in primary care networks: impact on outcomes and processes of care for patients with diabetes 
Background:
Primary care networks are a newer model of primary care that focuses on improved access to care and the use of multidisciplinary teams for patients with chronic disease. We sought to determine the association between enrolment in primary care networks and the care and outcomes of patients with diabetes.
Methods:
We used administrative health care data to study the care and outcomes of patients with incident and prevalent diabetes separately. For patients with prevalent diabetes, we compared those whose care was managed by physicians who were or were not in a primary care network using propensity score matching. For patients with incident diabetes, we studied a cohort before and after primary care networks were established. Each cohort was further divided based on whether or not patients were cared for by physicians enrolled in a network. Our primary outcome was admissions to hospital or visits to emergency departments for ambulatory care sensitive conditions specific to diabetes.
Results:
Compared with patients whose prevalent diabetes is managed outside of primary care networks, patients in primary care networks had a lower rate of diabetes-specific ambulatory care sensitive conditions (adjusted incidence rate ratio 0.81, 95% confidence interval [CI] 0.75 to 0.87), were more likely to see an ophthalmologist or optometrist (risk ratio 1.19, 95% CI 1.17 to 1.21) and had better glycemic control (adjusted mean difference −0.067, 95% CI −0.081 to −0.052).
Interpretation:
Patients whose diabetes was managed in primary care networks received better care and had better clinical outcomes than patients whose condition was not managed in a network, although the differences were very small.
doi:10.1503/cmaj.110755
PMCID: PMC3273535  PMID: 22143232
8.  A Tutorial on Methods to Estimating Clinically and Policy-Meaningful Measures of Treatment Effects in Prospective Observational Studies: A Review 
In randomized controlled trials (RCTs), treatment assignment is unconfounded with baseline covariates, allowing outcomes to be directly compared between treatment arms. When outcomes are binary, the effect of treatment can be summarized using relative risks, absolute risk reductions and the number needed to treat (NNT). When outcomes are time-to-event in nature, the effect of treatment on the absolute reduction of the risk of an event occurring within a specified duration of follow-up and the associated NNT can be estimated. In observational studies of the effect of treatments on health outcomes, treatment is frequently confounded with baseline covariates. Regression adjustment is commonly used to estimate the adjusted effect of treatment on outcomes. We highlight several limitations of measures of treatment effect that are directly obtained from regression models. We illustrate how both regression-based approaches and propensity-score based approaches allow one to estimate the same measures of treatment effect as those that are commonly reported in RCTs. The CONSORT statement recommends that both relative and absolute measures of treatment effects be reported for RCTs with dichotomous outcomes. The methods described in this paper will allow for similar reporting in observational studies.
doi:10.2202/1557-4679.1285
PMCID: PMC3404554  PMID: 22848188
randomized controlled trials; observational studies; causal effects; treatment effects; absolute risk reduction; relative risk reduction; number needed to treat; odds ratio; survival time; propensity score; propensity-score matching; regression; non-randomized studies; confounding
9.  Systematic review and evaluation of web-accessible tools for management of diabetes and related cardiovascular risk factors by patients and healthcare providers 
Objective
To identify and evaluate the effectiveness, clinical usefulness, sustainability, and usability of web-compatible diabetes-related tools.
Data sources
Medline, EMBASE, CINAHL, Cochrane Central Register of Controlled Trials, world wide web.
Study selection
Studies were included if they described an electronic audiovisual tool used as a means to educate patients, care givers, or clinicians about diabetes management and assessed a psychological, behavioral, or clinical outcome.
Data extraction
Study abstraction and evaluation for clinical usefulness, sustainability, and usability were performed by two independent reviewers.
Results
Of 12616 citations and 1541 full-text articles reviewed, 57 studies met inclusion criteria. Forty studies used experimental designs (25 randomized controlled trials, one controlled clinical trial, 14 before–after studies), and 17 used observational designs. Methodological quality and ratings for clinical usefulness and sustainability were variable, and there was a high prevalence of usability errors. Tools showed moderate but inconsistent effects on a variety of psychological and clinical outcomes including HbA1c and weight. Meta-regression of adequately reported studies (12 studies, 2731 participants) demonstrated that, although the interventions studied resulted in positive outcomes, this was not moderated by clinical usefulness nor usability.
Limitation
This review is limited by the number of accessible tools, exclusion of tools for mobile devices, study quality, and the use of non-validated scales.
Conclusion
Few tools were identified that met our criteria for effectiveness, usefulness, sustainability, and usability. Priority areas include identifying strategies to minimize website attrition and enabling patients and clinicians to make informed decisions about website choice by encouraging reporting of website quality indicators.
doi:10.1136/amiajnl-2011-000307
PMCID: PMC3384097  PMID: 22215057
Diabetes mellitus; medical informatics; medical education; patient education; endocrinology; knowledge translation; quality improvement; process redesign; CPOE; information; EMR
10.  Association between chronic cerebrospinal venous insufficiency and multiple sclerosis: a meta-analysis 
Background:
It has been proposed by Zamboni and colleagues that multiple sclerosis is caused by chronic cerebrospinal venous insufficiency, a term used to describe ultrasound-detectable abnormalities in the anatomy and flow of intra- and extracerebral veins. We conducted a meta-analysis of studies that reported the frequency of chronic cerebrospinal venous insufficiency among patients with and those without multiple sclerosis.
Methods:
We searched MEDLINE and EMBASE as well as bibliographies of relevant articles for eligible studies. We included studies if they used ultrasound to diagnose chronic cerebrospinal venous insufficiency and compared the frequency of the venous abnormalities among patients with and those without multiple sclerosis.
Results:
We identified eight eligible studies: all included healthy controls, and four of them also included a control group of patients with neurologic diseases other than multiple sclerosis. Chronic cerebrospinal venous insufficiency was more frequent among patients with multiple sclerosis than among the healthy controls (odds ratio [OR] 13.5, 95% confidence interval [CI] 2.6–71.4), but there was extensive unexplained heterogeneity among the studies. The association remained significant in the most conservative sensitivity analysis (OR 3.7, 95% CI 1.2–11.0), in which we removed the initial study by Zamboni and colleagues and added a study that did not find chronic cerebrospinal venous insufficiency in any patient. Although chronic cerebrospinal venous insufficiency was also more frequent among patients with multiple sclerosis than among controls with other neurologic diseases (OR 32.5, 95% CI 0.6–1775.7), the association was not statistically significant, the 95% CI was wide, and the OR was less extreme after removal of the study by Zamboni and colleagues (OR 3.5, 95% 0.8–15.8).
Interpretation:
Our findings showed a positive association between chronic cerebrospinal venous insufficiency and multiple sclerosis. However, poor reporting of the success of blinding and marked heterogeneity among the studies included in our review precluded definitive conclusions.
doi:10.1503/cmaj.111074
PMCID: PMC3216446  PMID: 21969411
11.  Association of echocardiography before major elective non-cardiac surgery with postoperative survival and length of hospital stay: population based cohort study 
Objective To determine the association of resting echocardiography before elective intermediate to high risk non-cardiac surgery with survival and length of hospital stay.
Design Population based retrospective cohort study.
Setting Acute care hospitals in Ontario, Canada, between 1 April 1999 and 31 March 2008.
Participants Patients aged over 40 years who had elective intermediate to high risk non-cardiac surgery.
Intervention Resting echocardiography within 6 months before surgery.
Main outcome measures Postoperative survival (30 days and 1 year) and length of hospital stay; postoperative surgical site infection as an outcome for which no association with echocardiography would be expected.
Results Of the 264 823 patients in the entire cohort, 15.1% (n=40 084) had echocardiography. After use of propensity score methods to assemble a matched cohort (n=70 996) that reduced differences between patients who had or had not had echocardiography, echocardiography was associated with increases in 30 day mortality (relative risk 1.14, 95% confidence interval 1.02 to 1.27), 1 year mortality (1.07, 1.01 to 1.12), and length of hospital stay but no difference in surgical site infections (1.03, 0.98 to 1.06). The association with mortality was influenced (P=0.02) by whether patients had had stress testing or had risk factors for cardiac complications. No association existed between echocardiography and mortality among patients who had stress testing (relative risk 1.01, 0.92 to 1.11) or among patients at high risk who had not had stress testing (1.00, 0.87 to 1.13). However, echocardiography was associated with mortality in patients at low risk (relative risk 1.44, 1.14 to 1.82) and intermediate risk (1.10, 1.02 to 1.18) who had not had stress testing.
Conclusions Preoperative echocardiography was not associated with improved survival or shorter hospital stay after major non-cardiac surgery. These findings highlight the need for further research to guide better use of this common preoperative test.
doi:10.1136/bmj.d3695
PMCID: PMC3127454  PMID: 21724560
12.  Accepting new patients 
Canadian Family Physician  2011;57(2):e68-e73.
Abstract
Objective
To gauge the public’s opinion of the College of Physicians and Surgeons of Ontario’s (CPSO’s) policy on how primary care physicians should accept new patients.
Design
Deliberative citizens’ council.
Setting
Toronto, Ont.
Participants
Twenty-five public members of the Toronto Health Policy Citizens’ Council.
Methods
A 2-day council session was held, during which the new policy was presented and council members heard from experts with various perspectives on the issues involved. Council members then deliberated and developed recommendations concerning the policy.
Main findings
Council members agreed that a first-come, first-served policy was an appropriate method for family physicians to use when accepting new patients. They thought the policy’s exception, which allows physicians not to accept patients based on a lack of clinical competency in an area, should be clarified in order to avoid it being used as an excuse to inappropriately screen patients. Counsel members also encouraged the CPSO to publicize its policy as widely as possible, so that potential patients undergoing screening in the future will recognize that this goes against the CPSO’s policy and can take appropriate action if they wish.
Conclusion
How family physicians accept new patients into their practices is a sensitive issue. The CPSO policy provides guidance on how new patients should be admitted, which, if it is appropriately enacted, seems reasonable to informed members of the public.
PMCID: PMC3038835  PMID: 21642708
13.  Endovascular treatment for multiple sclerosis: The intersection of science, policy and the public 
Open Medicine  2010;4(4):e197-e199.
The Canadian Institutes of Health Research and the Multiple Sclerosis (MS) Society of Canada recently convened an Invitational Panel to consider the scientific evidence linking chronic cerebrospinal venous insufficiency (CCSVI) and MS. The panel supported studies to determine whether CCSVI causes MS, but felt that there is currently so much uncertainty about the relationship between CCSVI and MS that a clinical trial is not indicated at this time. This commentary argues that the decision about whether a clinical trial is warranted must be informed by science, but should be addressed from a broader societal perspective. We suggest that members of the public should be more actively involved in scientifically based, but patient-relevant and emotionally charged issues considered by organizations that fund health research.
PMCID: PMC3090110  PMID: 21687341
14.  Public views on a wait time management initiative: a matter of communication 
Background
Many countries have tried to reduce waiting times for health care through formal wait time reduction strategies. Our paper describes views of members of the public about a wait time management initiative - the Ontario Wait Time Strategy (OWTS) (Canada). Scholars and governmental reports have advocated for increased public involvement in wait time management. We provide empirically derived recommendations for public engagement in a wait time management initiative.
Methods
Two qualitative studies: 1) an analysis of all emails sent by the public to the (OWTS) email address; and 2) in-depth interviews with members of the Ontario public.
Results
Email correspondents and interview participants supported the intent of the OWTS. However they wanted more information about the Strategy and its actions. Interview participants did not feel they were sufficiently made aware of the Strategy and email correspondents requested additional information beyond what was offered on the Strategy's website. Moreover, the email correspondents believed that some of the information that was provided on the Strategy's website and through the media was inaccurate, misleading, and even dishonest. Interview participants strongly supported public involvement in the OWTS priority setting.
Conclusions
Findings suggest the public wanted increased communication from and with the OWTS. Effective communication can facilitate successful public engagement, and in turn fair and legitimate priority setting. Based on the study's findings we developed concrete recommendations for improving public involvement in wait time management.
doi:10.1186/1472-6963-10-228
PMCID: PMC2922208  PMID: 20687952
15.  Attitudes of Family Physicians, Specialists and Radiologists about the Use of Computed Tomography and Magnetic Resonance Imaging in Ontario 
Healthcare Policy  2009;5(1):54-65.
Background:
Despite efforts to reduce wait times for computed tomography (CT) and magnetic resonance imaging (MRI) in Ontario, little is known about physicians' attitudes regarding contemporary patterns of CT and MRI scan use in this province.
Methods:
We interviewed 19 Ontario family physicians, specialists and radiologists from diverse settings between November 2006 and April 2007. Our detailed written notes were independently reviewed to identify major recurring themes.
Results:
Major themes were grouped under two categories: (a) non-clinical reasons for ordering CT and MRI (“defensive ordering,” indeterminate imaging reports, patient demand, supply-induced demand, marked variation in ordering practices) and (b) communication among groups of physicians (increasing isolation between clinicians and radiologists; specialists and family physicians working in silos).
Conclusion:
These interviews revealed infrequent communication among physician groups and marked variations in ordering practices that are often driven by a number of non-clinical factors, such as fear of litigation and patient demand. Recent increases in CT and MRI capacity may not be leading to better care for patients. Our findings, however, are very preliminary and require validation in other studies.
PMCID: PMC2732655  PMID: 20676251
16.  Provider volumes and early outcomes of primary total joint replacement in Ontario 
Canadian Journal of Surgery  2010;53(3):175-183.
Background
A relation between provider volume and outcome of total joint replacement (TJR) has not been demonstrated in Canada. Given the recent increase in TJR, changing patient characteristics and small sizes of previous Ontario studies, we reassessed whether adverse outcomes of TJR are related to hospital and surgeon procedure volumes.
Methods
We included all Ontarians aged 20 years and older who underwent a unilateral elective primary total hip replacement (THR) or total knee replacement (TKR) between April 2000 and March 2004. The main data sources were hospital discharge abstracts and physician billings. We defined provider volume as the average annual number of primary and revision procedures performed by hospitals and surgeons during the study period. We assessed the association between procedure volumes and acute length of hospital stay (ALOS) and between volume and rate of surgical complications during the index admission; death within 90 days of operation; readmission for amputation, fusion or excision within 1 year; and revision arthroplasty within 1 year. We adjusted for age, sex, comorbidity, arthritis type, teaching hospital status and discharge disposition. The analyses of hospital volume were adjusted for surgeon volume and vice versa.
Results
We included 20 290 patients who received THR and 27 217 who received TKR. Patient age, sex and comorbidity were significant predictors of complications and mortality. There were no associations between provider volume and mortality. Findings for other outcomes were mixed. Surgeon procedure volume was related to rates of revision THR but not to rates of revision TKR. Shorter ALOS was associated with male sex, younger age, fewer comorbidities, discharge to a rehabilitation unit or facility and greater surgeon volume.
Conclusion
Patient characteristics were significant predictors of complications, ALOS and mortality after primary TJR. Evidence for a relation between provider volume and outcome was limited and inconsistent.
PMCID: PMC2878994  PMID: 20507790
17.  Forecasting the Need for Dialysis Services in Ontario, Canada to 2011 
Healthcare Policy  2009;4(4):e151-e161.
Careful projections of the demand for dialysis services are important to assist healthcare planners in forecasting the need for equipment, facilities and personnel. We used time series techniques to model the historical incidence and prevalence counts and to forecast the predicted number of patients requiring dialysis in the province of Ontario to 2011. We showed that the incidence and prevalence of dialysis patients continues to grow rapidly. More importantly, traditional definitions of “chronic dialysis” capture only 52% of all incident patients and ignore the acute dialysis population. Projections about the need for dialysis services based on these definitions may result in underestimation of the resources required to care for the end-stage renal disease (ESRD) population.
PMCID: PMC2700710  PMID: 20436799
18.  Proliferation of prenatal ultrasonography 
Background
The extent to which temporal increases in the use of prenatal ultrasonography reflect changes in maternal risk is unknown. In this population-based study, we examined the use of prenatal ultrasonography from 1996 to 2006 in Ontario.
Methods
With fiscal year 1996/97 as the baseline, we evaluated the relative risk (RR) and 95% confidence interval (CI) for the change in rates of ultrasonography for each subsequent year. The RR was adjusted for maternal age, income, rural residence, maternal comorbidities, receipt of genetics consultation or amniocentesis — all in the index pregnancy — and history of complications in a prior pregnancy.
Results
The study sample consisted of 1 399 389 singleton deliveries. The rate of prenatal ultrasonography increased from 2055 per 1000 pregnancies in 1996 to 3264 per 1000 in 2006 (adjusted RR 1.55, 95% CI 1.54–1.55). The rate increased among both women with low-risk pregnancies (adjusted RR 1.54, 95% CI 1.53–1.55) and those with high-risk pregnancies (adjusted RR 1.55, 95% CI 1.54–1.57). The proportion of pregnancies with at least four ultrasound examinations in the second or third trimesters rose from 6.4% in 1996 to 18.7% in 2006 (adjusted RR 2.68, 95% CI 2.61–2.74). Paradoxically, this increase was more pronounced among low-risk pregnancies (adjusted RR 2.92, 95% CI 2.83–3.01) than among high-risk pregnancies (adjusted RR 2.25, 95% CI 2.16–2.35).
Interpretation
Substantial increases in the use of prenatal ultrasonography over the past decade do not appear to reflect changes in maternal risk. Nearly one in five women now undergo four or more ultrasound examinations during the second and third trimesters. Efforts to promote more appropriate use of prenatal ultrasonography for singleton pregnancies appear warranted.
doi:10.1503/cmaj.090979
PMCID: PMC2817321  PMID: 20048009
19.  Non-invasive cardiac stress testing before elective major non-cardiac surgery: population based cohort study 
Objective To determine the association of non-invasive cardiac stress testing before elective intermediate to high risk non-cardiac surgery with survival and hospital stay.
Design Population based retrospective cohort study.
Setting Acute care hospitals in Ontario, Canada, between 1 April 1994 and 31 March 2004.
Participants Patients aged 40 years or older who underwent specific elective intermediate to high risk non-cardiac surgical procedures.
Interventions Non-invasive cardiac stress testing performed within six months before surgery.
Main outcome measures Postoperative one year survival and length of stay in hospital.
Results Of the 271 082 patients in the entire cohort, 23 991 (8.9%) underwent stress testing. After propensity score methods were used to reduce important differences between patients who did or did not undergo preoperative stress testing and assemble a matched cohort (n=46 120), testing was associated with improved one year survival (hazard ratio (HR) 0.92, 95% CI 0.86 to 0.99; P=0.03) and reduced mean hospital stay (difference −0.24 days, 95% CI −0.07 to −0.43; P<0.001). In an analysis of subgroups defined by Revised Cardiac Risk Index (RCRI) class, testing was associated with harm in low risk patients (RCRI 0 points: HR 1.35, 95% CI 1.05 to 1.74), but with benefit in patients who were at intermediate risk (RCRI 1-2 points: 0.92, 95% CI 0.85 to 0.99) or high risk (RCRI 3-6 points: 0.80, 95% CI 0.67 to 0.97).
Conclusions Preoperative non-invasive cardiac stress testing is associated with improved one year survival and length of hospital stay in patients undergoing elective intermediate to high risk non-cardiac surgery. These benefits principally apply to patients with risk factors for perioperative cardiac complications.
doi:10.1136/bmj.b5526
PMCID: PMC2813428  PMID: 20110306
20.  Cholinesterase Inhibitors and Hospitalization for Bradycardia: A Population-Based Study 
PLoS Medicine  2009;6(9):e1000157.
Laura Park-Wyllie and colleagues examined the health records of more than 1.4 million older adults and show that initiation of cholinesterase inhibitor therapy is associated with a more than doubling of the risk of hospitalization for bradycardia.
Background
Cholinesterase inhibitors are commonly used to treat dementia. These drugs enhance the effects of acetylcholine, and reports suggest they may precipitate bradycardia in some patients. We aimed to examine the association between use of cholinesterase inhibitors and hospitalization for bradycardia.
Methods and Findings
We examined the health care records of more than 1.4 million older adults using a case-time-control design, allowing each individual to serve as his or her own control. Case patients were residents of Ontario, Canada, aged 67 y or older hospitalized for bradycardia between January 1, 2003 and March 31, 2008. Control patients (3∶1) were not hospitalized for bradycardia, and were matched to the corresponding case on age, sex, and a disease risk index. All patients had received cholinesterase inhibitor therapy in the 9 mo preceding the index hospitalization. We identified 1,009 community-dwelling older persons hospitalized for bradycardia within 9 mo of using a cholinesterase inhibitor. Of these, 161 cases informed the matched analysis of discordant pairs. Of these, 17 (11%) required a pacemaker during hospitalization, and six (4%) died prior to discharge. After adjusting for temporal changes in drug utilization, hospitalization for bradycardia was associated with recent initiation of a cholinesterase inhibitor (adjusted odds ratio [OR] 2.13, 95% confidence interval [CI] 1.29–3.51). The risk was similar among individuals with pre-existing cardiac disease (adjusted OR 2.25, 95% CI 1.18–4.28) and those receiving negative chronotropic drugs (adjusted OR 2.34, 95% CI 1.16–4.71). We found no such association when we replicated the analysis using proton pump inhibitors as a neutral exposure. Despite hospitalization for bradycardia, more than half of the patients (78 of 138 cases [57%]) who survived to discharge subsequently resumed cholinesterase inhibitor therapy.
Conclusions
Among older patients, initiation of cholinesterase inhibitor therapy was associated with a more than doubling of the risk of hospitalization for bradycardia. Resumption of therapy following discharge was common, suggesting that the cardiovascular toxicity of cholinesterase inhibitors is underappreciated by clinicians.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Alzheimer disease and other forms of dementia principally affect people aged over 65. These conditions result in confusion, long term memory loss, irritability, and mood swings. As the population of developed countries ages, the prevalence of dementia is expected to increase significantly. It is forecast that the proportion of people with dementia in the US will quadruple by 2045.
A common treatment for Alzheimer disease is a class of drug called an acetylcholinesterase inhibitor or cholinesterase inhibitor. These include donepezil (brand name Aricept), rivastigmine (marketed as Exelon and Exelon Patch), and galantamine (branded Razadyne).
The benefit of taking cholinesterase inhibitors is generally small and they cannot reverse the effects of dementia. In about 50% of patients they delay the worsening of symptoms for between six months and a year, although a small number of patients may benefit more. They can have unpleasant side effects, which may include diarrhoea and muscle cramps.
Why Was This Study Done?
Existing evidence is inconclusive on whether cholinesterase inhibitors increase the risk of bradycardia, an abnormally slow resting heart rate of below 60 beats a minute, which can cause fatigue, dizziness, fainting, palpitations, shortness of breath, or death. In this paper, the authors use routinely collected health care data to investigate whether an older person taking a cholinesterase inhibitor is at increased risk of bradycardia.
What Did the Researchers Do and Find?
They began by supposing that cholinesterase inhibitors might induce bradycardia soon after a patient first began to take them. To investigate this, they obtained health care data on 1.4 million patients aged 67 or over in Ontario, Canada. They identified 161 patients who had visited a hospital for bradycardia and who had previously taken a cholinesterase inhibitor only within specific periods of time. They found that 139 had taken a cholinesterase inhibitor within the previous three months compared with 22 who had stopped taking it at least six months before.
They compared these cases with up to three “control” patients who matched each of the initial “case” group of 161 patients by age, sex, and risk of bradycardia on the basis of their general health. None of the 466 controls had visited a hospital for bradycardia by the “index date,” that is, the date of hospitalization of the case patient they matched. The researchers found 349 of the control patients had begun to take a cholinesterase inhibitor in the three months prior to the index date, compared with 117 who had stopped taking it at least six months before. A statistical analysis of these data showed that recent initiation of cholinesterase inhibitors was associated with approximately a doubling of the risk of hospitalization for bradycardia.
The authors repeated their procedure to see whether another class of drug, proton pump inhibitors, had a similar effect. As they had expected, it did not. They repeated the analysis for patients taking into account other drugs that slow the heart rate and found that their increased risk of bradycardia when taking a cholinesterase inhibitor persisted. The increase in risk was also similar in patients with pre-existing heart problems.
The researchers' data also showed that, excluding patients who while in the hospital had a pacemaker fitted to control their heart rate, over half of the patients released from hospital started taking a cholinesterase inhibitor again. Of these, a few returned to hospital with bradycardia within 100 days.
What Do These Findings Mean?
Recent guidelines suggest that doctors should not prescribe cholinesterase inhibitors for dementia patients as a matter of course, but weigh the potential risks and benefits. This paper provides evidence of an additional risk, of which at least some doctors are unaware. It was not possible to compare risk for different cholinesterase inhibitors because most patients took donepezil.
A population-based study like this cannot prove that cholinesterase inhibitors cause bradycardia. The authors used routinely collected data and so did not have information on all relevant risk factors, and thus there remains a possibility of bias due to unmeasured factors. In addition the authors had to make assumptions, for instance that patients took the drugs prescribed for them. They also considered only diagnoses of bradycardia made by a hospital doctor and not those made elsewhere, which means the incidence of bradycardia may have been underestimated. A strength of the study is the use of a case-time-control design, which has the advantage of reducing bias due to the different health conditions and lifestyle of individual patients, and also bias due to factors changing over time.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1000157.
Wikipedia contains information on Alzheimer disease (note that Wikipedia is a free online encyclopedia that anyone can edit; available in several languages)
Information on bradycardia and its causes can be found in Wikipedia (note that Wikipedia is a free online encyclopedia that anyone can edit; available in several languages)
The UKs National Health Service provides information on dementia, including symptoms, causes, diagnosis, treatment, and prevention
MedlinePlus provides US-based health information (in English and Spanish)
The US National Institute on Aging provides information on health, relevant to older people, including Alzheimer Disease and dementia (in English and Spanish)
The US Alzheimers Association contains useful information on the disease, including on medication
The Public Health Agency of Canada website provides information on senior health (in English and French)
The UK-based Alzheimers Society provides advice on caring for people with dementia
doi:10.1371/journal.pmed.1000157
PMCID: PMC2742897  PMID: 19787032
21.  Administrative Data Algorithms Can Describe Ambulatory Physician Utilization 
Health Services Research  2007;42(4):1783-1796.
Objective
To validate algorithms using administrative data that characterize ambulatory physician care for patients with a chronic disease.
Data Sources
Seven-hundred and eighty-one people with diabetes were recruited mostly from community pharmacies to complete a written questionnaire about their physician utilization in 2002. These data were linked with administrative databases detailing health service utilization.
Study Design
An administrative data algorithm was defined that identified whether or not patients received specialist care, and it was tested for agreement with self-report. Other algorithms, which assigned each patient to a primary care and specialist physician, were tested for concordance with self-reported regular providers of care.
Principal Findings
The algorithm to identify whether participants received specialist care had 80.4 percent agreement with questionnaire responses (κ = 0.59). Compared with self-report, administrative data had a sensitivity of 68.9 percent and specificity 88.3 percent for identifying specialist care. The best administrative data algorithm to assign each participant's regular primary care and specialist providers was concordant with self-report in 82.6 and 78.2 percent of cases, respectively.
Conclusions
Administrative data algorithms can accurately match self-reported ambulatory physician utilization.
doi:10.1111/j.1475-6773.2006.00681.x
PMCID: PMC1955277  PMID: 17610448
Validation studies; specialist care; chronic disease care; administrative data; primary care; diabetes mellitus
23.  The safety of aprotinin and lysine-derived antifibrinolytic drugs in cardiac surgery: a meta-analysis 
Background
Because of recent concerns about the safety of aprotinin, we updated our 2007 Cochrane review that compared the relative benefits and risks of aprotinin and the lysine analogues tranexamic acid and epsilon aminocaproic acid.
Methods
We searched electronic databases, including CENTRAL, MEDLINE, EMBASE, Google and Google Scholar for trials of antifibrinolytic drugs used in adults scheduled for cardiac surgery. Searches were updated to January 2008. By comparing aprotinin and the 2 lysine analogues to control, we derived indirect head-to-head comparisons of aprotinin to the other drugs. We derived direct estimates of risks and benefits by pooling estimates from head-to-head trials of aprotinin and tranexamic acid or epsilon aminocaproic acid.
Results
For indirect estimates, we identified 49 trials involving 182 deaths among 7439 participants. The summary relative risk (RR) for death with aprotinin versus placebo was 0.93 (95% confidence interval [CI] 0.69–1.25). In the 19 trials that included tranexamic acid, there were 24 deaths among 1802 participants. The summary RR was 0.55 (95% CI 0.24–1.25). From the risk estimates derived for individual drugs, we calculated an indirect summary RR of death with use of aprotinin versus tranexamic acid of 1.69 (95% CI 0.70–4.10). To calculate direct estimates of death for aprotinin versus tranexamic acid, we identified 13 trials with 107 deaths among 3537 participants. The summary RR was 1.43 (95% CI 0.98–2.08). Among the 1840 participants, the calculated estimates of death for aprotinin compared directly to epsilon aminocaproic acid was 1.49 (95% CI 0.98–2.28). We found no evidence of an increased risk of myocardial infarction with use of aprotinin compared with the lysine analogues in either direct or indirect analyses. Compared with placebo or no treatment, all 3 drugs were effective in reducing the need for red blood cell transfusion. The RR of transfusion with use of aprotinin was 0.66 (95% CI 0.61–0.72). The RR of transfusion was 0.70 (95% CI 0.61–0.80) for tranexamic acid, and it was 0.75 (95% CI 0.58–0.96) for use of epsilon aminocaproic acid. Aprotinin was also effective in reducing the need for re-operation because of bleeding (RR 0.48, 95% CI 0.34–0.67).
Interpretation
The risk of death tended to be consistently higher with use of aprotinin than with use of lysine analogues. Aprotinin had no clear advantages to offset these harms. Either tranexamic acid or epsilon aminocaproic acid should be recommended to prevent bleeding after cardiac surgery.
doi:10.1503/cmaj.081109
PMCID: PMC2621296  PMID: 19050037
25.  Moving from opacity to transparency in pharmaceutical policy 
doi:10.1503/cmaj.070799
PMCID: PMC2228347  PMID: 18268270

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