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1.  What Drives Variation in Episode-of-care Payments for Primary TKA? An Analysis of Medicare Administrative Data 
Episode-of-care payments are defined as a single lump-sum payment for all services associated with a single medical event or surgery and are designed to incentivize efficiency and integration among providers and healthcare systems. A TKA is considered an exemplar for an episode-of-care payment model by many policymakers, but data describing variation payments between hospitals for TKA are extremely limited.
We asked: (1) How much variation is there between hospitals in episode-of-care payments for primary TKA? (2) Is variation in payment explained by differences in hospital structural characteristics such as teaching status or geographic location, patient factors (age, sex, ethnicity, comorbidities), and discharge disposition during the postoperative period (home versus skilled nursing facility)? (3) After accounting for those factors, what proportion of the observed variation remains unexplained?
We used Medicare administrative data to identify fee-for-service beneficiaries who underwent a primary elective TKA in 2009. After excluding low-volume hospitals, we created longitudinal records for all patients undergoing TKAs in eligible hospitals encompassing virtually all payments by Medicare for a 120-day window around the TKA (30 days before to 90 days after). We examined payments for the preoperative, perioperative, and postdischarge periods based on the hospital where the TKA was performed. Confounding variables were controlled for using multivariate analyses to determine whether differences in hospital payments could be explained by differences in patient demographics, comorbidity, or hospital structural factors.
There was considerable variation in payments across hospitals. Median (interquartile range) hospital preoperative, perioperative, postdischarge, and 120-day payments for patients who did not experience a complication were USD 623 (USD 516-768), USD 13,119 (USD 12,165-14,668), USD 8020 (USD 6403-9933), and USD 21,870 (USD 19,736-25,041), respectively. Variation cannot be explained by differences in hospital structure. Median (interquartile range) episode payments were greater for hospitals in the Northeast (USD 26,291 [22,377-30,323]) compared with the Midwest, South, and West (USD 20,614, [USD 18,592-22.968]; USD 21,584, [USD 19,663-23,941]; USD 22,421, [USD 20,317-25,860]; p < 0.001) and for teaching compared with nonteaching hospitals (USD 23,152 [USD 20,426-27,127] versus USD 21,336 [USD 19,352-23,846]; p < 0.001). Patient characteristics explained approximately 15% of the variance in hospital payments, hospital characteristics (teaching status, geographic region) explained 30% of variance, and approximately 55% of variance was not explained by either factor.
There is much unexplained variation in episode-of-care payments at the hospital-level, suggesting opportunities for enhanced efficiency. Further research is needed to ensure an appropriate balance between such efficiencies and access to care.
Level of Evidence
Level II, economic analysis.
Electronic supplementary material
The online version of this article (doi:10.1007/s11999-015-4445-0) contains supplementary material, which is available to authorized users.
PMCID: PMC4586190  PMID: 26239239
2.  Symptom Assessment in Knee Osteoarthritis Needs to Account for Physical Activity Level 
Pain is not always correlated with radiographic osteoarthritis (OA) severity possibly because people modify activities to manage symptoms. Measures of symptoms that consider pain in the context of activity level may therefore provide greater discrimination than pain alone. Our objective was to compare discrimination of a measure of pain alone with combined measures of pain relative to physical activity across radiographic OA levels.
This is a cross-sectional study of the Osteoarthritis Initiative accelerometer substudy, including those with and without knee OA. Two composite pain and activity knee symptom (PAKS) scores were calculated as Western Ontario and McMaster (WOMAC) Universities Osteoarthritis Pain Scale plus one divided by physical activity measures (step and activity counts). Symptom score discrimination across Kellgren and Lawrence (KL) grades were evaluated using histograms and quantile regression.
1806 participants, mean age 65.1 (9.1) years, mean BMI 28.4 (4.8) kg/m2, and 55.6% female, were included. WOMAC, but not PAKS scores, exhibited a floor effect. Adjusted median WOMAC by KL grades 0 – 4 were 0, 0, 1, 1, and 3 respectively. Median PAKS1 and PAKS2 were 24.9, 26.0, 32.4, 46.1, 97.9, and 7.2, 7.2, 9.2, 12.9, 23.8, respectively. PAKS scores had more statistically significant comparisons between KL grades compared with WOMAC.
Symptom assessments incorporating pain and physical activity did not exhibit a floor effect and were better able to discriminate radiographic severity than pain alone, particularly in milder disease. Pain in the context of physical activity level should be used to assess knee OA symptoms.
PMCID: PMC4626322  PMID: 26407008
3.  Commonalities and differences in the implementation of models of care for arthritis: key informant interviews from Canada 
Timely access to effective treatments for arthritis is a priority at national, provincial and regional levels in Canada due to population aging coupled with limited health human resources. Models of care for arthritis are being implemented across the country but mainly in local contexts, not from an evidence-informed policy or framework. The purpose of this study is to examine existing models of care for arthritis in Canada at the local level in order to identify commonalities and differences in their implementation that could point to important considerations for health policy and service delivery.
Semi-structured key informant interviews were conducted with 70 program managers and/or care providers in three Canadian provinces identified through purposive and snowball sampling followed by more detailed examination of 6 models of care (two per province). Interviews were transcribed verbatim and analyzed thematically using a qualitative descriptive approach.
Two broad models of care were identified for Total Joint Replacement and Inflammatory Arthritis. Commonalities included lack of complete and appropriate referrals from primary care physicians and lack of health human resources to meet local demands. Strategies included standardized referrals and centralized intake and triage using non-specialist health care professionals. Differences included the nature of the care and follow-up, the role of the specialist, and location of service delivery.
Current models of care are mainly focused on Total Joint Replacement and Inflammatory Arthritis. Given the increasing prevalence of arthritis and that published data report only a small proportion of current service delivery is specialist care; provision of timely, appropriate care requires development, implementation and evaluation of models of care across the continuum of care.
Electronic supplementary material
The online version of this article (doi:10.1186/s12913-016-1634-9) contains supplementary material, which is available to authorized users.
PMCID: PMC4992288  PMID: 27543108
Models of care; Arthritis; Total joint replacement
4.  The boot camp program for lumbar spinal stenosis: a protocol for a randomized controlled trial 
Lumbar spinal stenosis (LSS) causing neurogenic claudication is a leading cause of pain, disability and loss of independence in older adults. The prevalence of lumbar spinal stenosis is growing rapidly due to an aging population. The dominant limitation in LSS is walking ability. Postural, physical and psychosocial factors can impact symptoms and functional ability. LSS is the most common reason for spine surgery in older adults yet the vast majority of people with LSS receive non-surgical treatment. What constitutes effective non-surgical treatment is unknown. The purpose of this study is to evaluate the effectiveness of a multi-modal and self-management training program, known as the Boot Camp Program for LSS aimed at improving walking ability and other relevant patient-centred outcomes.
We will use a pragmatic two-arm randomized controlled single blinded (assessor) study design. Eligible and consenting participants will be randomized to receive from licensed chiropractors either a 6-week (twice weekly) self-management training program (manual therapy, education, home exercises) with an instructional workbook and video and a pedometer or a single instructional session with an instructional workbook and video and pedometer. The main outcome measure will be the self-paced walking test measured at 6 months. We will also assess outcomes at 8 weeks and 3 and 12 months.
Symptoms and functional limitations in LSS are variable and influenced by changes in spinal alignment. Physical and psychological factors result in chronic disability for patients with LSS. The Boot Camp Program is a 6-week self-management training program aimed at the multi-faceted aspects of LSS and trains individuals to use self-management strategies. The goal is to provide life-long self-management strategies that maximize walking and overall functional abilities and quality of life.
Trial registration ID: NCT02592642.
PMCID: PMC4948101  PMID: 27433335
Lumbar spinal stenosis; Neurogenic claudication; Self-management; Walking; Randomized controlled trial; Boot camp program; Multi-modal treatment; Non-surgical
5.  Improving System Integration: The Art and Science of Engaging Small Community Practices in Health System Innovation 
This paper focuses on successful engagement strategies in recruiting and retaining primary care physicians (PCPs) in a quality improvement project, as perceived by family physicians in small practices. Sustained physician engagement is critical for quality improvement (QI) aiming to enhance health system integration. Although there is ample literature on engaging physicians in hospital or team-based practice, few reports describe factors influencing engagement of community-based providers practicing with limited administrative support. The PCPs we describe participated in SCOPE: Seamless Care Optimizing the Patient Experience, a QI project designed to support their care of complex patients and reduce both emergency department (ED) visits and inpatient admissions. SCOPE outcome measures will inform subsequent papers. All the 30 participating PCPs completed surveys assessing perceptions regarding the importance of specific engagement strategies. Project team acknowledgement that primary care is challenging and new access to patient resources were the most important factors in generating initial interest in SCOPE. The opportunity to improve patient care via integration with other providers was most important in their commitment to participate, and a positive experience with project personnel was most important in their continued engagement. Our experience suggests that such providers respond well to personalized, repeated, and targeted engagement strategies.
PMCID: PMC4745601  PMID: 26904284
6.  Understanding Referral Patterns for Bone Mineral Density Testing among Family Physicians: A Qualitative Descriptive Study 
Journal of Osteoporosis  2016;2016:2937426.
Introduction. Evidence of inappropriate bone mineral density (BMD) testing has been identified in terms of overtesting in low risk women and undertesting among patients at high risk. In light of these phenomena, the objective of this study was to understand the referral patterns for BMD testing among Ontario's family physicians (FPs). Methods. A qualitative descriptive approach was adopted. Twenty-two FPs took part in a semi-structured interview lasting approximately 30 minutes. An inductive thematic analysis was performed on the transcribed data in order to understand the referral patterns for BMD testing. Results. We identified a lack of clarity about screening for osteoporosis with a tendency for baseline BMD testing in healthy, postmenopausal women and a lack of clarity on the appropriate age for screening for men in particular. A lack of clarity on appropriate intervals for follow-up testing was also described. Conclusions. These findings lend support to what has been documented at the population level suggesting a tendency among FPs to refer menopausal women (at low risk). Emphasis on referral of high-risk groups as well as men and further clarification and education on the appropriate intervals for follow-up testing is warranted.
PMCID: PMC4745655  PMID: 26904357
7.  Capturing the experiences of patients across multiple complex interventions: a meta-qualitative approach 
BMJ Open  2015;5(9):e007664.
The perspectives, needs and preferences of individuals with complex health and social needs can be overlooked in the design of healthcare interventions. This study was designed to provide new insights on patient perspectives drawing from the qualitative evaluation of 5 complex healthcare interventions.
Patients and their caregivers were recruited from 5 interventions based in primary, hospital and community care in Ontario, Canada.
We included 62 interviews from 44 patients and 18 non-clinical caregivers.
Our team analysed the transcripts from 5 distinct projects. This approach to qualitative meta-evaluation identifies common issues described by a diverse group of patients, therefore providing potential insights into systems issues.
Outcome measures
This study is a secondary analysis of qualitative data; therefore, no outcome measures were identified.
We identified 5 broad themes that capture the patients’ experience and highlight issues that might not be adequately addressed in complex interventions. In our study, we found that: (1) the emergency department is the unavoidable point of care; (2) patients and caregivers are part of complex and variable family systems; (3) non-medical issues mediate patients’ experiences of health and healthcare delivery; (4) the unanticipated consequences of complex healthcare interventions are often the most valuable; and (5) patient experiences are shaped by the healthcare discourses on medically complex patients.
Our findings suggest that key assumptions about patients that inform intervention design need to be made explicit in order to build capacity to better understand and support patients with multiple chronic diseases. Across many health systems internationally, multiple models are being implemented simultaneously that may have shared features and target similar patients, and a qualitative meta-evaluation approach, thus offers an opportunity for cumulative learning at a system level in addition to informing intervention design and modification.
PMCID: PMC4563230  PMID: 26351182
8.  Arthritis has an impact on the daily lives of Canadians young and old: results from a population-based survey 
There is a perception that the impacts of arthritis are greatest among older adults. However, the effect of age on health-related outcomes in individuals with arthritis has not been explicitly studied. This study examined whether the physical and mental health impacts of arthritis are greater in older (75+ years) versus younger (20–44, 45–64 and 65–74 years) Canadian adults.
Data were from the arthritis component of the 2009 Survey on Living with Chronic Diseases in Canada. The responses were weighted to be representative of Canadians (≥20 years) with arthritis. Associations between age and the prevalence of severe/frequent joint pain, severe/frequent fatigue, sleep limitations, instrumental activities of daily living (IADLs) limitations, high levels of stress, suboptimal general and suboptimal mental health, were examined descriptively prior to conducting multivariate log-binomial regression analyses.
A total of 4565 respondents completed the survey (78 % response rate). Individuals with arthritis were mostly female (63 %), of working age (57 %) and overweight or obese (67 %). Upon adjusting for covariates, younger (20–44 years) and/or middle aged (45–64 years) adults were more likely than those older (75+ years) to report severe/frequent joint pain, sleep limitations, high levels of stress and suboptimal mental health. After adjusting for covariates, age was not associated with IADL limitations, severe/frequent fatigue or suboptimal general health.
Contrary to the belief that older adults with arthritis experience more severe physical and mental health outcomes, we found that older adults were less likely to report worse outcomes than younger adults. In light of these findings, public health messaging should stress that arthritis does not just affect the elderly and emphasize the importance of timely diagnosis and management at all ages in order to prevent or, minimize arthritis-related impairment.
PMCID: PMC4553213  PMID: 26319735
9.  Understanding Preferences for Disease Modifying Drugs in Osteoarthritis 
Arthritis care & research  2014;66(8):1186-1192.
Numerous disease modifying drugs for osteoarthritis (DMOADs) are under investigation. However, patients’ preferences for drugs to prevent progression of OA are not known. The objective of this study was to quantify patient preferences for potential DMOADs.
We administered a conjoint analysis survey to 304 patients attending outpatient general medicine and specialty clinics. All patients seated in the waiting rooms were asked if they would participate in a survey to elicit opinions about arthritis treatments. We performed simulations to estimate preferences for four options to prevent worsening of knee OA: Best Case (pill, highest benefit, lowest risk, lowest cost), Worst Case (infusion, lowest benefit, highest risk, highest cost), Moderate Subcutaneous Injection (injection, lowest benefit, mid-level risk, mid-level cost), and Moderate Infusion (same as previous except administered by infusion).
Subjects’ median age was 57 years; 55% were female and 69% were Caucasian. Segmentation analyses revealed 4 patterns of preferences. A small minority (5%) who do not want to perform subcutaneous injections and will only consider DMOADs under the Best-Case scenario. Approximately 20% are risk sensitive and are willing to take DMOADs under the Best-Case scenario, but start rejecting these medications as risk increases. A significant number reject DMOADs under all conditions (16.4%); however, the largest segment (59.2%) has a strong preference for DMOADs across all scenarios.
Our results suggest that a significant percent of a non-selected outpatient population might be willing to accept at least a moderate degree of risk in order to prevent worsening knee OA.
PMCID: PMC4112164  PMID: 24470354
10.  Variability in Recommendations for Total Knee Arthroplasty among Rheumatologists and Orthopedic Surgeons 
The Journal of rheumatology  2013;41(1):10.3899/jrheum.130762.
The most rapidly growing population of patients undergoing total knee arthroplasty (TKA) is under the age of 65. The objective of this study was to gain insight into the factors influencing physicians’ recommendations for persons in this age group with moderate osteoarthritis (OA).
Rheumatologists and orthopedic surgeons attending national meetings were asked to complete a survey including a standardized scenario of a 62 year old person with knee OA who has moderate knee pain limiting strenuous activity despite medical management. We used an experimental 2×2×2 design to examine the effects of gender, employment status and severity of radiographic OA on physicians’ recommendations. Each physician was asked to rate a single scenario.
The percent of physicians recommending TKA varied from 30% to 55% for scenarios describing a patient with mild radiographic OA, and from 39% to 71% for scenarios describing a patient with moderate radiographic OA. Surgeons were less likely to recommend TKA for women compared to men of the same age, employment status, symptom severity and functional status, and x-rays. Rheumatologists practicing in academic settings were more likely to recommend TKA compared to those practicing in non-academic settings, and American surgeons were more likely to recommend TKA compared to their European counterparts.
Orthopedic surgeons and rheumatologists vary significantly in their recommendations for patients with moderate knee pain and functional limitations. Both patient and physician characteristics influence physicians’ recommendations and rheumatologists and orthopedic surgeons display different patterns of decision-making.
PMCID: PMC3880398  PMID: 24293580
Total Joint Arthroplasty; Practice Patterns; Physician Bias; Unwarranted Variability
11.  Expanding Paramedicine in the Community (EPIC): study protocol for a randomized controlled trial 
Trials  2014;15:473.
The incidence of chronic diseases, including diabetes mellitus (DM), heart failure (HF) and chronic obstructive pulmonary disease (COPD) is on the rise. The existing health care system must evolve to meet the growing needs of patients with these chronic diseases and reduce the strain on both acute care and hospital-based health care resources. Paramedics are an allied health care resource consisting of highly-trained practitioners who are comfortable working independently and in collaboration with other resources in the out-of-hospital setting. Expanding the paramedic’s scope of practice to include community-based care may decrease the utilization of acute care and hospital-based health care resources by patients with chronic disease.
This will be a pragmatic, randomized controlled trial comparing a community paramedic intervention to standard of care for patients with one of three chronic diseases. The objective of the trial is to determine whether community paramedics conducting regular home visits, including health assessments and evidence-based treatments, in partnership with primary care physicians and other community based resources, will decrease the rate of hospitalization and emergency department use for patients with DM, HF and COPD. The primary outcome measure will be the rate of hospitalization at one year. Secondary outcomes will include measures of health system utilization, overall health status, and cost-effectiveness of the intervention over the same time period. Outcome measures will be assessed using both Poisson regression and negative binomial regression analyses to assess the primary outcome.
The results of this study will be used to inform decisions around the implementation of community paramedic programs. If successful in preventing hospitalizations, it has the ability to be scaled up to other regions, both nationally and internationally. The methods described in this paper will serve as a basis for future work related to this study.
Trial registration NCT02034045. Date: 9 January 2014.
Electronic supplementary material
The online version of this article (doi:10.1186/1745-6215-15-473) contains supplementary material, which is available to authorized users.
PMCID: PMC4289358  PMID: 25467772
Randomized controlled trial; Community health services; Primary health care; Allied health personnel
12.  You’ll know when you’re ready: a qualitative study exploring how patients decide when the time is right for joint replacement surgery 
While some studies have identified patient readiness as a key component in their decision whether to have total joint replacement surgery (TJR), none have examined how patients determine their readiness for surgery. The study purpose was to explore the concept of patient readiness and describe the factors patients consider when assessing their readiness for TJR.
Nine focus groups (4 pre-surgery, 5 post-surgery) were held in four Canadian cities. Participants had been either referred to or seen by an orthopaedic surgeon for TJR or had undergone TJR. The method of analysis was qualitative thematic analysis.
There were 65 participants, 66% female and 34% male, 80% urban, with an average age of 65 years (SD 10). Readiness reflected both the surgeon’s advice that the patient was clinically ready for surgery and the patient’s feeling that they were both mentally and physically ready for surgery. Mental readiness was described as an internal state or feeling of being ready or prepared while physical readiness was described as being physically fit and in good shape for surgery. Factors associated with readiness included: 1) pain: its severity, the ability to cope with it, and how it affected their quality of life; 2) mental preparation; 3) physical preparation; 4) the optimal timing of surgery, including age, anticipated rate of deterioration, prosthesis lifespan and the length of the waiting list.
Patient readiness should be assessed prior to TJR. By assessing patient readiness, health professionals can elucidate and deal with concerns and fears, understand and calibrate expectations, assess coping strategies, and use this information to help determine optimal timing, both before and after the surgical consultation.
PMCID: PMC4283088  PMID: 25278186
Decision making; Readiness; Total joint replacement; Qualitative research; Osteoarthritis
13.  Obstructive sleep apnea and the prevalence and incidence of cancer 
A link between obstructive sleep apnea and cancer development or progression has been suggested, possibly through chronic hypoxemia, but supporting evidence is limited. We examined the association between the severity of obstructive sleep apnea and prevalent and incident cancer, controlling for known risk factors for cancer development.
We included all adults referred with possible obstructive sleep apnea who underwent a first diagnostic sleep study at a single large academic hospital between 1994 and 2010. We linked patient data with data from Ontario health administrative databases from 1991 to 2013. Cancer diagnosis was derived from the Ontario Cancer Registry. We assessed the cross-sectional association between obstructive sleep apnea and prevalent cancer at the time of the sleep study (baseline) using logistic regression analysis. Cox regression models were used to investigate the association between obstructive sleep apnea and incident cancer among patients free of cancer at baseline.
Of 10 149 patients who underwent a sleep study, 520 (5.1%) had a cancer diagnosis at baseline. Over a median follow-up of 7.8 years, 627 (6.5%) of the 9629 patients who were free of cancer at baseline had incident cancer. In multivariable regression models, the severity of sleep apnea was not significantly associated with either prevalent or incident cancer after adjustment for age, sex, body mass index and smoking status at baseline (apnea–hypopnea index > 30 v. < 5: adjusted odds ratio [OR] 0.96, 95% confidence interval [CI] 0.71–1.30, for prevalent cancer, and adjusted hazard ratio [HR] 1.02, 95% CI 0.80–1.31, for incident cancer; sleep time spent with oxygen saturation < 90%, per 10-minute increase: adjusted OR 1.01, 95% CI 1.00–1.03, for prevalent cancer, and adjusted HR 1.00, 95% CI 0.99–1.02, for incident cancer).
In a large cohort, the severity of obstructive sleep apnea was not independently associated with either prevalent or incident cancer. Additional studies are needed to elucidate whether there is an independent association with specific types of cancer.
PMCID: PMC4162778  PMID: 25096668
14.  The role of pain and functional impairment in the decision to recommend total joint replacement in hip and knee osteoarthritis: an international cross-sectional study of 1909 patients. Report of the OARSI-OMERACT Task Force on total joint replacement 
To assess the pain and functional disability levels corresponding to an indication for total joint replacement (TJR) in hip and knee osteoarthritis (OA).
Design: international cross-sectional study in 10 countries. Patients: consecutive outpatients with definite hip or knee OA attending an orthopaedic outpatient clinic. Gold standard measure for recommendation for TJR: surgeon's decision that TJR is justified. Outcome measures: pain (ICOAP: intermittent and constant osteoarthritis pain, 0-100) and functional impairment (HOOS-PS/KOOS-PS: Hip/Knee injury and Osteoarthritis Outcome Score Physical function Short-form, 0-100). Analyses: Comparison of patients with versus without surgeons' indication for TJR. ROC curve analyses and logistic regression were applied to determine cut-points of pain and disability defining recommendation for TJR.
In all, 1909 patients were included (1130 knee/779 hip OA). Mean age was 66.4 (SD 10.9) years, 58.1% were women; 628/1130 (55.6%) knee OA and 574/779 (73.7%) hip OA patients were recommended for TJR. Although patients recommended for TJR (yes versus no) had worse symptom levels (pain, 55.5 [95% confidence interval 54.2, 56.8] vs. 44.9 [43.2, 46.6], and functional impairment, 59.8 [58.7, 60.9] vs. 50.9 [49.3, 52.4], respectively, both p<0.0001), there was substantial overlap in symptom levels between groups, even when adjusting for radiographic joint status. Thus, it was not possible to determine cut points for pain and function defining ‘requirement for TJR’.
Although symptom levels were higher in patients recommended for TJR, pain and functional disability alone did not discriminate between those who were and were not considered to need TJR by the orthopaedic surgeon.
PMCID: PMC4151518  PMID: 21044689
Knee; hip; osteoarthritis; joint replacement; surgery; symptom
15.  Relation between surgeon volume and risk of complications after total hip arthroplasty: propensity score matched cohort study 
The BMJ  2014;348:g3284.
Objectives To identify a cut point in annual surgeon volume associated with increased risk of complications after primary elective total hip arthroplasty and to quantify any risk identified.
Design Propensity score matched cohort study.
Setting Ontario, Canada
Participants 37 881 people who received their first primary total hip arthroplasty during 2002-09 and were followed for at least two years after their surgery.
Main outcome measure The rates of various surgical complications within 90 days (venous thromboembolism, death) and within two years (infection, dislocation, periprosthetic fracture, revision) of surgery.
Results Multivariate splines were developed to visualize the relation between surgeon volume and the risk for various complications. A threshold of 35 cases a year was identified, under which there was an increased risk of dislocation and revision. 6716 patients whose total hip arthroplasty was carried out by surgeons who had done ≤35 such procedure in the previous year were successfully matched to patients whose surgeon had carried out more than 35 procedures. Patients in the former group had higher rates of dislocation (1.9% v 1.3%, P=0.006; NNH 172) and revision (1.5% v 1.0%, P=0.03; NNH 204).
Conclusions In a cohort of first time recipients of total hip arthroplasty, patients whose operation was carried by surgeons who had performed 35 or fewer such procedures in the year before the index procedure were at increased risk for dislocation and early revision. Surgeons should consider performing 35 cases or more a year to minimize the risk for complications. Furthermore, the methods used to visualize the relationship between surgeon volume and the occurrence of complications can be easily applied in any jurisdiction, to help inform and optimize local healthcare delivery.
PMCID: PMC4032026  PMID: 24859902
16.  Impact of a chronic disease self-management program on health care utilization in rural communities: a retrospective cohort study using linked administrative data 
Internationally, chronic disease self-management programs (CDSMPs) have been widely promoted with the assumption that confident, knowledgeable patients practicing self-management behavior will experience improved health and utilize fewer healthcare resources. However, there is a paucity of published data supporting this claim and the majority of the evidence is based on self-report.
We used a retrospective cohort study using linked administrative health data. Data from 104 tele-CDSMP participants from 13 rural and remote communities in the province of Ontario, Canada were linked to administrative databases containing emergency department (ED) and physician visits and hospitalizations. Patterns of health care utilization prior to and after participation in the tele-CDSMP were compared. Poisson Generalized Estimating Equations regression was used to examine the impact of the tele-CDSMP on health care utilization after adjusting for covariates.
There were no differences in patterns of health care utilization before and after participating in the tele-CDSMP. Among participants ≤ 66 years, however, there was a 34% increase in physician visits in the 12 months following the program (OR = 1.34, 95% CI 1.11-1.61) and a trend for decreased ED visits in those >66 years (OR = 0.59, 95% CI 0.33-1.06).
This is the first study to examine health care use following participation in the CDSMP in a Canadian population and to use administrative data to measure health care utilization. Similar to other studies that used self-report measures to evaluate health care use we found no differences in health care utilization before and after participation in the CDSMP. Future research needs to confirm our findings and examine the impact of the CDSMP on health care utilization in different age groups to help to determine whether these interventions are more effective with select population groups.
PMCID: PMC4036726  PMID: 24885135
17.  Impact of a change in physician reimbursement on bone mineral density testing in Ontario, Canada: a population-based study 
CMAJ Open  2014;2(2):E45-E50.
On Apr. 1, 2008, a revision was made to the fee schedule for bone mineral density testing with dual-energy x-ray absorptiometry (DXA) in the province of Ontario, Canada, reducing the frequency of repeat screening in individuals at low risk of osteoporosis. We evaluated whether the change in physician reimbursement successfully promoted appropriate bone mineral density testing, with reduced use among women at low risk and increased use among women and men at higher risk of osteoporosis-related fracture.
We analyzed data from administrative databases on physician billings, hospital discharges and emergency department visits. We included all physician claims for DXA in the province to assess patterns in bone mineral density testing from Apr. 1, 2002, to Mar. 31, 2011. People at risk of an osteoporosis-related fracture were defined as women and men aged 65 years or more and those who had a recent (< 6 mo) fracture after age 40 years. Joinpoint regression analysis was used to examine trends in DXA testing.
Before the policy change, the overall number of DXA tests increased from 433 419 in 2002/03 to 507 658 in 2007/08; after revision of the fee schedule, the number decreased to 422 915 by 2010/11. Most of this reduction was due to a decrease in the age-standardized rate of DXA testing among women deemed to be at low risk, from 5.7 per 100 population in 2008/09 to 1.8 per 100 in 2010/11. In the high-risk group of people aged 65 or more, the age-standardized rate of testing increased after the policy change among men but decreased among women. Among those at high risk because of a recent clinical fracture, the age-standardized rate of DXA testing increased for both sexes and then decreased after the policy change.
A change in reimbursement designed to restrict access to bone mineral density testing among low-risk women was associated with an overall reduction in testing. Efforts to communicate guidelines for bone mineral density testing with greater clarity, particularly as they relate to high-risk individuals, need to be explored.
PMCID: PMC4084743  PMID: 25077129
18.  All-Cause Mortality and Serious Cardiovascular Events in People with Hip and Knee Osteoarthritis: A Population Based Cohort Study 
PLoS ONE  2014;9(3):e91286.
Because individuals with osteoarthritis (OA) avoid physical activities that exacerbate symptoms, potentially increasing risk for cardiovascular disease (CVD) and death, we assessed the relationship between OA disability and these outcomes.
In a population cohort aged 55+ years with at least moderately severe symptomatic hip and/or knee OA, OA disability (Western Ontario McMaster Universities (WOMAC) OA scores; Health Assessment Questionnaire (HAQ) walking score; use of walking aids) and other covariates were assessed by questionnaire. Survey data were linked to health administrative data to determine the relationship between baseline OA symptom severity to all-cause mortality and occurrence of a composite CVD outcome (acute myocardial infarction, coronary revascularization, heart failure, stroke or transient ischemic attack) over a median follow-up of 13.2 and 9.2 years, respectively.
Of 2156 participants, 1,236 (57.3%) died and 822 (38.1%) experienced a CVD outcome during follow-up. Higher (worse) baseline WOMAC function scores and walking disability were independently associated with a higher all-cause mortality (adjusted hazard ratio, aHR, per 10-point increase in WOMAC function score 1.04, 95% confidence interval, CI 1.01–1.07, p = 0.004; aHR per unit increase in HAQ walking score 1.30, 95% CI 1.22–1.39, p<0.001; and aHR for those using versus not using a walking aid 1.51, 95% CI 1.34–1.70, p<0.001). In survival analysis, censoring on death, risk of our composite CVD outcome was also significantly and independently associated with greater baseline walking disability ((aHR for use of a walking aid  = 1.27, 95% CI 1.10–1.47, p = 0.001; aHR per unit increase in HAQ walking score  = 1.17, 95% CI 1.08–1.27, p<0.001).
Among individuals with hip and/or knee OA, severity of OA disability was associated with a significant increase in all-cause mortality and serious CVD events after controlling for multiple confounders. Research is needed to elucidate modifiable mechanisms.
PMCID: PMC3946823  PMID: 24608134
19.  Decision aid for patients considering total knee arthroplasty with preference report for surgeons: a pilot randomized controlled trial 
To evaluate feasibility and potential effectiveness of a patient decision aid (PtDA) for patients and a preference report for surgeons to reduce wait times and improve decision quality in patients with osteoarthritis considering total knee replacement.
A prospective two-arm pilot randomized controlled trial. Patients with osteoarthritis were eligible if they understood English and were referred for surgical consultation about an initial total knee arthroplasty at a Canadian orthopaedic joint assessment clinic. Patients were randomized to the PtDA intervention or usual education. The intervention was an osteoarthritis PtDA for patients and a one-page preference report summarizing patients’ clinical and decisional data for their surgeon. The main feasibility outcomes were rates of recruitment and questionnaire completion; the preliminary effectiveness outcomes were wait times and decision quality.
Of 180 patients eligible for surgical consultation, 142 (79%) were recruited and randomized to the PtDA intervention (n = 71) or usual education (n = 71). Data collection yielded a 93% questionnaire completion rate with less than 1% missing items. After one year, 13% of patients remained on the surgical wait list. The median time from referral to being off the wait list (censored using survival analysis techniques) was 33.4 weeks for the PtDA group (n = 69, 95% CI: 26.0, 41.4) and 33.0 weeks for usual education (n = 71, 95% CI: 26.1, 39.9). Patients exposed to the PtDA had higher decision quality based on knowledge (71% versus 47%; p < 0.0001) and quality decision being an informed choice that is consistent with their values for option outcomes (56.4% versus 25.0%; p < 0.001).
Recruitment of patients with osteoarthritis considering surgery and data collection were feasible. As some patients remained on the surgical waiting list after one year, follow-up should be extended to two years. Patients exposed to the PtDA achieved higher decision quality compared to those receiving usual education but there was no difference in wait for surgery.
Trials registration
ClinicalTrials.Gov NCT00743951
PMCID: PMC3937455  PMID: 24564877
Patient decision aids; Patient preferences; Osteoarthritis; Joint arthroplasty; Wait times; Decision quality
20.  Obstructive Sleep Apnea and Risk of Cardiovascular Events and All-Cause Mortality: A Decade-Long Historical Cohort Study 
PLoS Medicine  2014;11(2):e1001599.
Tetyana Kendzerska and colleagues explore the association between physiological measures of obstructive sleep apnea other than the apnea-hypopnea index and the risk of cardiovascular events.
Please see later in the article for the Editors' Summary
Obstructive sleep apnea (OSA) has been reported to be a risk factor for cardiovascular (CV) disease. Although the apnea-hypopnea index (AHI) is the most commonly used measure of OSA, other less well studied OSA-related variables may be more pathophysiologically relevant and offer better prediction. The objective of this study was to evaluate the relationship between OSA-related variables and risk of CV events.
Methods and Findings
A historical cohort study was conducted using clinical database and health administrative data. Adults referred for suspected OSA who underwent diagnostic polysomnography at the sleep laboratory at St Michael's Hospital (Toronto, Canada) between 1994 and 2010 were followed through provincial health administrative data (Ontario, Canada) until May 2011 to examine the occurrence of a composite outcome (myocardial infarction, stroke, congestive heart failure, revascularization procedures, or death from any cause). Cox regression models were used to investigate the association between baseline OSA-related variables and composite outcome controlling for traditional risk factors. The results were expressed as hazard ratios (HRs) and 95% CIs; for continuous variables, HRs compare the 75th and 25th percentiles. Over a median follow-up of 68 months, 1,172 (11.5%) of 10,149 participants experienced our composite outcome. In a fully adjusted model, other than AHI OSA-related variables were significant independent predictors: time spent with oxygen saturation <90% (9 minutes versus 0; HR = 1.50, 95% CI 1.25–1.79), sleep time (4.9 versus 6.4 hours; HR = 1.20, 95% CI 1.12–1.27), awakenings (35 versus 18; HR = 1.06, 95% CI 1.02–1.10), periodic leg movements (13 versus 0/hour; HR = 1.05, 95% CI 1.03–1.07), heart rate (70 versus 56 beats per minute [bpm]; HR = 1.28, 95% CI 1.19–1.37), and daytime sleepiness (HR = 1.13, 95% CI 1.01–1.28).The main study limitation was lack of information about continuous positive airway pressure (CPAP) adherence.
OSA-related factors other than AHI were shown as important predictors of composite CV outcome and should be considered in future studies and clinical practice.
Please see later in the article for the Editors' Summary
Editors' Summary
Obstructive sleep apnea (OSA) is a common sleep-related breathing disorder, particularly among middle-aged and elderly people. It is characterized by apnea—a brief interruption in breathing that lasts at least 10 seconds—and hypopnea—a decrease of more than 50% in the amplitude of breathing that lasts at least 10 seconds or clear but smaller decrease in amplitude associated with either oxygen desaturation or an arousal. Patients with OSA experience numerous episodes of apnea and hypopnea during the night; severe OSA is defined as having 30 or more episodes per hour (an apnea-hypopnea index [AHI] of >30). These breathing interruptions occur when relaxation of the upper airway muscles decreases the airflow, which lowers the amount of oxygen in the blood. As a result, affected individuals frequently wake from deep sleep as they struggle to breathe. Symptoms of OSA include loud snoring and daytime sleepiness. Treatments include lifestyle changes such as losing weight (excess fat around the neck increases airway collapse) and smoking cessation. For severe OSA, doctors recommend continuous positive airway pressure (CPAP), in which a machine blows pressurized air through a face mask into the airway to keep it open.
Why Was This Study Done?
OSA can be life-threatening. Most directly, daytime sleepiness can cause accidents, but OSA is also associated with an increased risk of developing cardiovascular disease (CVD, disease that affects the heart and the circulation). To date, studies that have investigated the association between OSA and the risk of myocardial infarction (heart attack), congestive heart failure, stroke, and other CVDs have used the AHI to diagnose and categorize the severity of OSA. However, by focussing on AHI, clinicians and researchers may be missing opportunities to improve their ability to predict which patients are at the highest risk of CVD. In this historical cohort study, the researchers investigate the association between other OSA-related variables (for example, blood oxygen saturation and sleep fragmentation) and the risk of cardiovascular events and all-cause mortality (death). A historical cohort study examines the medical records of groups of individuals who have different characteristics at baseline for the subsequent occurrence of specific outcomes.
What Did the Researchers Do and Find?
The researchers used administrative data (including hospitalization records and physicians' claims for services supplied to patients) to follow up adults referred for suspected OSA who underwent diagnostic polysomnography (a sleep study) at a single Canadian hospital between 1994 and 2010. A database of the polysomnography results provided information on OSA-related variables for all the study participants. Over an average follow-up of about 6 years, 11.5% of the 10,149 participants were hospitalized for a myocardial infarction, stroke, or congestive heart failure, underwent a revascularization procedure (an intervention that restores the blood supply to an organ or tissue after CVD has blocked a blood vessel), or had died from any cause. After adjusting for multiple established risk factors for CVD such as smoking and age in Cox regression models (a statistical approach that examines associations between patient variables and outcomes), several OSA-related variables (but not AHI) were significant predictors of CVD. The strongest OSA-related predictor of cardiovascular events or all-cause mortality was total sleep time spent with oxygen saturation below 90%, which increased the risk of a cardiovascular event or death by 50%. Other statistically significant OSA-related predictors (predictors that were unlikely to be associated with the outcome through chance) of cardiovascular events or death included total sleep time, number of awakenings, frequency of periodic leg movements, heart rate, and daytime sleepiness.
What Do These Findings Mean?
These findings indicate that OSA-related factors other than AHI are important predictors of the composite outcome of a cardiovascular event or all-cause mortality. Indeed, although AHI was significantly associated with the researchers' composite outcome in an analysis that did not consider other established risk factors for CVD (“confounders”), the association became non-significant after controlling for potential confounders. The accuracy of these findings, which need to be confirmed in other settings, is likely to be limited by the lack of information available about the use of CPAP by study participants and by the lack of adjustment for some important confounders. Importantly, however, these findings suggest that OSA-related factors other than AHI should be considered as predictors of CVD in future studies and in clinical practice.
Additional Information
Please access these websites via the online version of this summary at
The US National Heart Lung and Blood Institute has information (including several videos) about obstructive sleep apnea (in English and Spanish), sleep studies, heart disease, and other cardiovascular diseases (some information in English and Spanish)
The UK National Health Service Choices website provides information (including personal stories) about sleep apnea and about cardiovascular disease
The not-for-profit American Sleep Apnea Association provides detailed information about sleep apnea for patients and health-care professionals, including personal stories about the condition
The MedlinePlus encyclopedia has pages on obstructive sleep apnea and on polysomnography; MedlinePlus provides links to further information and advice about obstructive sleep apnea, heart diseases, and vascular diseases (in English and Spanish)
PMCID: PMC3913558  PMID: 24503600
21.  The relation between total joint arthroplasty and risk for serious cardiovascular events in patients with moderate-severe osteoarthritis: propensity score matched landmark analysis 
The BMJ  2013;347:f6187.
Objective To examine whether total joint arthroplasty of the hip and knee reduces the risk for serious cardiovascular events in patients with moderate-severe osteoarthritis.
Design Propensity score matched landmark analysis.
Setting Ontario, Canada.
Participants 2200 adults with hip or knee osteoarthritis aged 55 or more at recruitment (1996-98) and followed prospectively until death or 2011.
Main outcome measure Rates of serious cardiovascular events for those who received a primary total joint arthroplasty compared with those did not within an exposure period of three years after baseline assessment.
Results The propensity score matched cohort consisted of 153 matched pairs of participants with moderate-severe arthritis. Over a median follow-up period of seven years after the landmark date (start of the study), matched participants who underwent a total joint arthroplasty during the exposure period were significantly less likely than those who did not to experience a cardiovascular event (hazards ratio 0.56, 95% confidence interval 0.43 to 0.74, P<0.001). Within seven years of the exposure period the absolute risk reduction was 12.4% (95% confidence interval 1.7% to 23.1%) and number needed to treat was 8 (95% confidence interval 4 to 57 patients).
Conclusions Using a propensity matched landmark analysis in a population cohort with advanced hip or knee osteoarthritis, this study found a cardioprotective benefit of primary elective total joint arthroplasty.
PMCID: PMC3813386  PMID: 24174640
22.  Comparison of orally administered bisphosphonate drugs in reducing the risk of hip fracture in older adults: a population-based cohort study 
CMAJ Open  2013;1(3):E97-E105.
Orally administered bisphosphonate drugs (i.e., alendronate, etidronate, risedronate) can reduce the risk of vertebral fracture. However, only alendronate and risedronate have proven efficacy in reducing the risk of hip fracture. We sought to examine the comparative effectiveness of orally administered bisphosphonate drugs in reducing hip fractures among older adults.
We identified new users of orally administered bisphosphonate drugs in British Columbia and Ontario between 2001 and 2008. We used province- and sex-specific propensity score–matching strategies to maximize comparability between exposure groups. We used Cox proportional hazards models to compare time-to-hip fracture within 1 year of treatment between exposures by sex in each province. Our secondary analyses considered hip fracture rates within 2 and 3 years’ follow-up. We used alendronate as the reference for all comparisons and pooled provincial estimates using random effects variance-weighted meta-analysis.
We identified 321 755 patients who were eligible for inclusion in the study. We found little difference in fracture rates between men (pooled hazard ratio [HR] 0.94, 95% confidence interval [CI] 0.74–1.14) or women (pooled HR 1.15, 95% CI 0.73–1.56) taking risedronate and those taking alendronate. We similarly identified little difference in fracture rates between women taking etidronate and those taking alendronate (pooled HR 1.00, 95% CI 0.82–1.18). However, we identified lower rates of hip fracture among men taking etidronate relative to alendronate (pooled HR 0.77, 95% CI 0.60–0.94). Results extended to 2 and 3 years’ follow-up were similar. However, with 3 years’ follow-up, rates of hip fracture were lower among women in British Columbia who had taken alendronate.
We identified little overall difference between alendronate and risedronate in reducing the risk of hip fracture in men or women. Our finding that etidronate is associated with lower fracture risk among men is likely due to selection bias. The long-term comparative effects of orally administered bisphosphonate drugs warrant further study.
PMCID: PMC3986012  PMID: 25077113
23.  Increasing Access to Chronic Disease Self-Management Programs in Rural and Remote Communities Using Telehealth 
Telemedicine Journal and e-Health  2013;19(6):467-473.
Objective: This study examined whether a telehealth chronic disease self-management program (CDSMP) would lead to improvements in self-efficacy, health behaviors, and health status for chronically ill adults living in Northern Ontario, Canada. Two telehealth models were used: (1) single site, groups formed by participants at one telehealth site; and (2) multi-site, participants linked from multiple sites to form one telehealth group, as a strategy to increase access to the intervention for individuals living in rural and remote communities. Subjects and Methods: Two hundred thirteen participants diagnosed with heart disease, stroke, lung disease, or arthritis attended the CDSMP at a preexisting Ontario Telemedicine Network studio from September 2007 to June 2008. The program includes six weekly, peer-facilitated sessions designed to help participants develop important self-management skills to improve their health and quality of life. Baseline and 4-month follow-up surveys were administered to assess self-efficacy beliefs, health behaviors, and health status information. Results were compared between single- and multi-site delivery models. Results: Statistically significant improvements from baseline to 4-month follow-up were found for self-efficacy (6.6±1.8 to 7.0±1.8; p<0.001), exercise behavior, cognitive symptom management, communication with physicians, role function, psychological well-being, energy, health distress, and self-rated health. There were no statistically significant differences in outcomes between single- and multi-site groups. Conclusions: Improvements in self-efficacy, health status, and health behaviors were equally effective in single- and multi-site groups. Access to self-management programs could be greatly increased with telehealth using single- and multi-site groups in rural and remote communities.
PMCID: PMC3696947  PMID: 23570277
telehealth; policy; cardiology/cardiovascular disease; self-care
24.  The Challenge of Pain for Patients with OA 
HSS Journal  2012;8(1):42-44.
PMCID: PMC3295951  PMID: 23372528
symptoms; pain; quality of life; fatigue; osteoarthritis outcomes; Medicine & Public Health; Rheumatology; Imaging / Radiology; Anesthesiology; Orthopedics; Surgical Orthopedics; Sports Medicine
25.  OARSI/OMERACT Initiative to Define States of Severity and Indication for Joint Replacement in Hip and Knee Osteoarthritis. An OMERACT 10 Special Interest Group 
The Journal of Rheumatology  2011;38(8):1765-1769.
To define pain and physical function cutpoints that would, coupled with structural severity, define a surrogate measure of “need for joint replacement surgery,” for use as an outcome measure for potential structure-modifying interventions for osteoarthritis (OA).
New scores were developed for pain and physical function in knee and hip OA. A cross-sectional international study in 1909 patients was conducted to define data-driven cutpoints corresponding to the orthopedic surgeons’ indication for joint replacement. A post hoc analysis of 8 randomized clinical trials (1379 patients) evaluated the prevalence and validity of cutpoints, among patients with symptomatic hip/knee OA.
In the international cross-sectional study, there was substantial overlap in symptom levels between patients with and patients without indication for joint replacement; indeed, it was not possible to determine cutpoints for pain and function defining this indication. The post hoc analysis of trial data showed that the prevalence of cases that combined radiological progression, high level of pain, and high degree of function impairment was low (2%–12%). The most discriminatory cutpoint to define an indication for joint replacement was found to be [pain (0–100) + physical function (0–100) > 80].
These results do not support a specific level of pain or function that defines an indication for joint replacement. However, a tentative cutpoint for pain and physical function levels is proposed for further evaluation. Potentially, this symptom level, coupled with radiographic progression, could be used to define “nonresponders” to disease-modifying drugs in OA clinical trials.
PMCID: PMC3260473  PMID: 21807799

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