Jacek A Kopec

University of British Columbia - Vancouver, Vancouver, British Columbia, Canada

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Publications (176)611.53 Total impact

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    ABSTRACT: Objective To outline the clinical presentation, physical examination findings, diagnostic criteria, and management options of femoroacetabular impingement (FAI). Sources of information PubMed was searched for relevant articles regarding the pathogenesis, diagnosis, treatment, and prognosis of FAI. Main message In recent years, FAI has been increasingly recognized as a potential precursor and an important contributor to hip pain in the adult population and idiopathic hip osteoarthritis later in life. Femoroacetabular impingement is a collection of bony morphologic abnormalities of the hip joint that result in abnormal contact during motion. Cam-type FAI relates to a non-spherical osseous prominence of the proximal femoral neck or head-neck junction. Pincer-type FAI relates to excessive acetabular coverage over the femoral head, which can occur owing to several morphologic variants. Patients with FAI present with chronic, deep, or aching anterior groin pain most commonly in the sitting position, or during or after activity. Patients might also experience occasional sharp pains during activity. A thorough history should be taken that includes incidence of trauma and exercise frequency. A physical examination should be performed that includes a full hip, low back, and abdominal examination to assess for alternate causes of anterior groin pain. Diagnosis of FAI should be confirmed with radiography. Femoroacetabular impingement can be managed conservatively with rest, modification of activities, medications, and physiotherapy, or it can be treated surgically. Conclusion Femoroacetabular impingement is an important cause of anterior groin pain. Early recognition and intervention by the primary care provider might be critical to alleviating morbidity and preventing FAI progression.
    No preview · Article · Dec 2015
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    ABSTRACT: Background: Osteoarthritis (OA) is the most common joint disease and a major cause of disability. Incidence and prevalence of OA are expected to increase due to population aging and increased levels of obesity. Objective: The purpose of this study was to project the effect of hypothetical interventions that change the distribution of body mass index (BMI) on OA burden in Canada. Methods: We used a microsimulation computer model of OA called POHEM-OA. The model used demographic predictions for Canada and population data from an administrative database in British Columbia and national Canadian surveys. Results: Under the base-case scenario, between 2010 and 2030 OA prevalence is expected to increase from 11.5% to 15.6% in men and 16.3% to 21.1% in women. In scenarios assuming, on average, a 0.3, 0.5 or 1-unit drop in BMI/year, OA prevalence in 2030 would reach 14.9%, 14.6% and 14.2% in men and 20.3%, 19.7%, and 18.5%, in women, respectively. Under these scenarios, the proportion of new cases prevented would be 9.5%, 13.2% and 16.7%, respectively, in men, and 9.1%, 15.2% and 25.0% in women. Targeting only those aged 50 years or older for weight reduction would achieve about 70% of the impact of a full population strategy. Targeting only the obese (BMI>30) would likely result in a larger benefit for men than women. Conclusions: Due to the aging of the population, OA will remain a major and growing health issue in Canada over the next two decades, regardless of the course of the obesity epidemic. This article is protected by copyright. All rights reserved.
    No preview · Article · Nov 2015
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    ABSTRACT: The POpulation HEalth Model (POHEM) is a health microsimulation model that was developed at Statistics Canada in the early 1990s. POHEM draws together rich multivariate data from a wide range of sources to simulate the lifecycle of the Canadian population, specifically focusing on aspects of health. The model dynamically simulates individuals' disease states, risk factors, and health determinants, in order to describe and project health outcomes, including disease incidence, prevalence, life expectancy, health-adjusted life expectancy, quality of life, and healthcare costs. Additionally, POHEM was conceptualized and built with the ability to assess the impact of policy and program interventions, not limited to those taking place in the healthcare system, on the health status of Canadians. Internationally, POHEM and other microsimulation models have been used to inform clinical guidelines and health policies in relation to complex health and health system problems. This paper provides a high-level overview of the rationale, methodology, and applications of POHEM. Applications of POHEM to cardiovascular disease, physical activity, cancer, osteoarthritis, and neurological diseases are highlighted.
    Full-text · Article · Sep 2015 · Population Health Metrics
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    ABSTRACT: Objective To determine the association of body mass index (BMI) with incidence and progression of knee effusion on magnetic resonance imaging (MRI) and physical examination (PE) in a longitudinal cohort with knee pain.MethodsA population-based cohort was assessed at baseline and 3 years (N=163). BMI was categorized: normal (<25), overweight (25–29.9), obese (≥30). Knee effusion was graded 0-3 (absent/mild/moderate/severe) on MRI and 0-1 (absent/present) on PE. Progression of MRI effusion (MRIeff) was an increase of ≥1 grade in those with grade 1 or 2 at baseline. Incident MRIeff and PE effusion (PEeff) are any effusion at follow-up (>0) in those with grade 0 at baseline. A second type of incident MRIeff was effusion grade ≥2 at follow-up in those with grade <2 at baseline. Exponential regression analysis was used, adjusted for age, sex and radiographic severity.ResultsIncident MRIeff≥1, incident MRIeff≥2, incident PEeff, and progression of MRIeff were seen in 14/73 (19%), 18/140 (13%), 26/127 (20%) and 18/86 (21%), respectively. There was a borderline statistical association of obesity with progression of MRIeff (HR 3.3, 95%CI 1.0-11.2) and with incident MRIeff≥2 (HR 3.4, 95%CI 1.0-11.5). BMI was not associated with incident MRIeff≥1 (HR [95%CI] overweight: 1.1 [0.3-3.6]; obese 1.0 [0.2-5.0]). Overweight was associated with incident PEeff (HR 4.5, 95%CI 1.4-14.2), while obesity was not statistically significant (HR 3.1, 95%CI 0.9-11.1).Conclusion Obesity was a risk factor for incident and progressive knee effusion in this population-based cohort. These findings highlight an important link between obesity and inflammation in knee OA. This article is protected by copyright. All rights reserved.
    No preview · Article · Aug 2015
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    ABSTRACT: To estimate the future direct cost of OA in Canada using a population-based health microsimulation model of osteoarthritis (POHEM-OA). We used administrative health data from the province of British Columbia (BC), Canada, a survey of a random sample of BC residents diagnosed with OA (Ministry of Health of BC data), Canadian Institute of Health Information (CIHI) cost data and literature estimates to populate a microsimulation model. Cost components associated with pharmacological and non-pharmacological treatments, total joint replacement surgery, as well as use of hospital resources and management of complications arising from the treatment of osteoarthritis were included. Future costs were then simulated using the POHEM-OA model to construct profiles for each adult Canadian. From 2010 to 2031, as the prevalence of OA is projected to increase from 13.8% to 18.6%, the total direct cost of OA is projected to increase from $2.9 billion to $7.6 billion, an almost 2.6-fold increase (in 2010 $CAD). From the highest to the lowest, the cost components that will constitute the total direct cost of OA in 2031 are hospitalization cost ($2.9 billion), outpatient services ($1.2 billion), alternative care and out-of-pocket cost categories ($1.2 billion), drugs ($1 billion), rehabilitation ($0.7 billion) and side-effect of drugs ($0.6 billion). Projecting the future trends in the cost of OA enables policy makers to anticipate the significant shifts in its distribution of burden in the future. Copyright © 2015. Published by Elsevier Ltd.
    No preview · Article · Jun 2015 · Osteoarthritis and Cartilage
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    ABSTRACT: Background Femoroacetabular impingement (FAI) and physical activity involving hip flexion have been suggested as key risk factors for hip pain among young and middle-aged individuals [1] but population studies have been lacking. Objectives To determine if physical activity involving hip flexion is a risk factor for persistent or recurrent hip pain in young and middle-aged persons with and without FAI. Methods A population sample of persons aged 20-49 with (cases) and without (controls) hip pain in Metro Vancouver, Canada, was selected through random digit dialing. Hip pain was defined as pain in the groin or upper thigh in the past 12 months that lasted 6 weeks or longer or occurred on 3 or more occasions. Subjects completed a lifetime physical activity questionnaire including domestic, occupational and sports/recreational activities. Flexion scores were calculated from reported total hours of activities involving hip flexion>70 degrees (e.g., squatting, kneeling, skiing, rowing, but excluding sitting). Data on peak hip flexion for various activities were derived from the literature. Standardized X-rays of the pelvis/hips with AP and Dunn views were obtained. FAI was defined as one or more of the following: lateral centre edge angle (LCE) >40°, alpha angle >55° and positive cross-over sign. We analyzed the relationship between flexion scores and hip pain among persons with and without FAI using logistic regression. In secondary analyses we a) used hip (rather than person) as the unit of analysis; b) considered only activities prior to the onset of pain. Odds ratios (OR) are reported for a one standard deviation difference in flexion scores. Results Data were obtained for 500 subjects, 269 cases and 231 controls. Mean age was 43 years in both groups, 34% of the cases and 39% of the controls were male. Prevalence of radiographic FAI was 49% in the cases and 43% in the controls. Mean (SD, range) flexion scores were 78 (126, 0-1074) in the cases and 60 (112, 0-782) in the controls for work/domestic activities, and 25 (37, 0-198) and 24 (48, 0-306) for sports activities, respectively. After adjusting for age and sex, a higher flexion score for work/domestic activities was associated with hip pain in subjects with FAI (OR=1.54, 1.01-2.35) but not in those without FAI (OR=1.10, 0.89-1.36). For sports/recreational activities, flexion score was not significantly associated with pain in either group (OR=0.90, 0.71-1.14 and OR=1.25, 0.93-1.68 for those with and without FAI, respectively). The hip-based analysis and the analysis limited to activities prior to the onset of pain showed similar results. Conclusions A one SD increase in the frequency of domestic and work-related activities involving hip flexion is associated with a 50% increase in the risk of persistent or recurrent hip pain in young and middle-aged persons with radiographic FAI. This finding may help understand the causes of hip osteoarthritis. References Acknowledgements The study was supported by a grant from the Canadian Institutes of Health Research. Disclosure of Interest None declared
    No preview · Article · Jun 2015 · Annals of the Rheumatic Diseases
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    ABSTRACT: Objectives: The CAT-5D-QOL is a previously reported item response theory (IRT)-based computerized adaptive tool to measure five domains (attributes) of health-related quality of life. The objective of this study was to develop and validate a multiattribute health utility (MAHU) scoring method for this instrument. Study design and setting: The MAHU scoring system was developed in two stages. In phase I, we obtained standard gamble (SG) utilities for 75 hypothetical health states in which only one domain varied (15 states per domain). In phase II, we obtained SG utilities for 256 multiattribute states. We fit a multiplicative regression model to predict SG utilities from the five IRT domain scores. The prediction model was constrained using data from phase I. We validated MAHU scores by comparing them with the Health Utilities Index Mark 3 (HUI3) and directly measured utilities and by assessing between-group discrimination. Results: MAHU scores have a theoretical range from -0.842 to 1. In the validation study, the scores were, on average, higher than HUI3 utilities and lower than directly measured SG utilities. MAHU scores correlated strongly with the HUI3 (Spearman ρ = 0.78) and discriminated well between groups expected to differ in health status. Conclusion: Results reported here provide initial evidence supporting the validity of the MAHU scoring system for the CAT-5D-QOL.
    No preview · Article · Apr 2015 · Journal of clinical epidemiology

  • No preview · Article · Apr 2015 · Osteoarthritis and Cartilage
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    Full-text · Article · Apr 2015 · Osteoarthritis and Cartilage
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    ABSTRACT: Objectives. Our aim was to determine the risk of diabetes among osteoarthritis (OA) cases in a prospective longitudinal study. Methods. Administrative health records of 577,601 randomly selected individuals from British Columbia, Canada, from 1991 to 2009, were analyzed. OA and diabetes cases were identified by checking physician's visits and hospital records. From 1991 to 1996 we documented 19,143 existing OA cases and selected one non-OA individual matched by age, sex, and year of administrative records. Poisson regression and Cox proportional hazards models were fitted to estimate the effects after adjusting for available sociodemographic and medical factors. Results. At baseline, the mean age of OA cases was 61 years and 60.5% were women. Over 12 years of mean follow-up, the incidence rate (95% CI) of diabetes was 11.2 (10.90-11.50) per 1000 person years. Adjusted RRs (95% CI) for diabetes were 1.27 (1.15-1.41), 1.21 (1.08-1.35), 1.16 (1.04-1.28), and 0.99 (0.86-1.14) for younger women (age 20-64 years), older women (age ≥ 65 years), younger men, and older men, respectively. Conclusion. Younger adults and older women with OA have increased risks of developing diabetes compared to their age-sex matched non-OA counterparts. Further studies are needed to confirm these results and to elucidate the potential mechanisms.
    Full-text · Article · Nov 2014 · International Journal of Rheumatology
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    ABSTRACT: Identifying persons with early rheumatoid arthritis (RA) is a major challenge. The role of the Internet in making decisions about seeking care has not been studied. We developed a method for early diagnosis and referral using the Arthritis Foundation's website. A person with less than 3 months of joint pain symptom who has not yet sought medical attention was screened. Prescreened persons are linked to a self-scoring questionnaire and get a "likelihood" of RA statement. If "likely," the person is offered a free evaluation and biomarker testing performed by Quest Diagnostics. The system available only to Massachusetts's residents yielded a small steady flow of screen-positive individuals. Over 21 months, 43,244 persons took the Arthritis Foundation website prescreening questionnaire; 196 were from Massachusetts and 60 took the self-scoring algorithm. Of the 48 who screened positive, 29 set up an appointment for a free evaluation, but six never came in. Twenty-four subjects were evaluated and diagnosed independently by three rheumatologists. One met the 1987 American College of Rheumatology (ACR) criteria for RA and two met the 2010 ACR/EULAR RA criteria. The 24 examined individuals were contacted at a minimum of 1 year and asked to redo the case-finding questionnaire and asked about their health resource utilization during the interval. Seventeen of the 24 subjects responded, and 10 had seen a health professional. Three of the 17 had a diagnosis of RA; all were on at least methotrexate. Internet case finding was useful in identifying new potential RA cases. The system's performance characteristics are theoretically limited only by the number of study sites available. However, the major barrier may be that seeing a health professional is not a priority for many individuals with early symptoms.
    No preview · Article · Oct 2014 · Clinical Rheumatology

  • No preview · Article · Oct 2014 · Quality of Life Research

  • No preview · Article · Sep 2014 · International journal of radiation oncology, biology, physics
  • J A Kopec · J Ogonowski · Md M Rahman · T Miazgowski
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    ABSTRACT: Background Gestational Diabetes Mellitus (GDM) is a common health problem among pregnant women and may be associated with distress. Purpose The purpose of the study was to describe changes in patient-reported outcomes in women with GDM and identify factors associated with increased distress in these patients. Research Design The study was conducted in 205 women diagnosed with GDM. Study participants underwent a physical examination and completed a questionnaire two times during pregnancy. On average, the questionnaire was completed at 27 weeks of gestation at baseline and 36 weeks at follow-up. The questionnaire included socio-demographic and clinical variables, standardized patient-reported outcome measures, and questions about the impact of GDM on daily life, satisfaction with care, knowledge about GDM, and social and professional support. Our main outcome of interest was diabetes-related distress, measured by the Problem Areas in Diabetes (PAID) questionnaire. Data were analyzed using descriptive statistics and multivariable regression models. Results At baseline, 80 % of the women were satisfied with their diabetes care and 58 % said they managed their diabetes well. The proportion reporting little or no knowledge of GDM dropped from almost 50 % at baseline to 14 % at follow-up. However, the proportion reporting that GDM affected their social life increased from 26 to 35 %, and the proportion reporting interference with family life increased from 14 to 26 %. Insulin treatment, frequency of blood glucose measurements, lack of knowledge about GDM, and lack of support from family and health care providers were strongly and significantly associated with distress. Conclusion In women with GDM, intensified treatment and lack of informational and social support are associated with distress. These aspects of GDM care appear to be appropriate targets for future research and interventions aimed at reducing the level of distress in these patients.
    No preview · Article · Aug 2014 · International Journal of Behavioral Medicine
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    ABSTRACT: Objective: To evaluate the validity (accuracy) and reliability of 2 commonly used clinical methods, 1 indirect (lifts) and 1 direct (tape measure), for assessment of leg length discrepancy (LLD) in comparison to radiograph. Methods: Twenty subjects suspected of having LLD participated in this study. Two clinical methods, 1 direct using a tape measure and 1 indirect using lifts, were standardized and carried out by 4 examiners. Difference in height of the femoral heads on standing pelvic radiograph was measured and served as the gold standard. Results: The intraclass correlation coefficient assessing interobserver reliability was 0.737 for lifts and 0.477 for tape measure. The remainder of the analysis is based on the average of the measurements by the 4 examiners. Pearson correlation coefficients were 0.93 for the lifts and 0.75 for the tape measure method. Paired sample t tests showed difference in means of 2 mm (p = 0.051) for lifts and -5 mm (p = 0.007) for tape measure compared with radiograph. Sensitivity and specificity were 55% and 89% for lifts and 45% and 56% for tape measure, respectively, using > 5 mm as the definition for LLD. The wrong leg was identified as being shorter in 1 out of 20 subjects using lifts versus 7 out of 20 using tape measure. Conclusion: The indirect standing method of LLD measurement using lifts had superior validity, interobserver reliability, and specificity in comparison with radiograph over the direct supine method using tape measure. Both clinical methods underestimated LLD compared with radiograph.
    No preview · Article · Jul 2014 · The Journal of Rheumatology

  • No preview · Conference Paper · Jul 2014

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  • No preview · Conference Paper · Jul 2014
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    ABSTRACT: Background Bone marrow lesions (BML) occur commonly in knee osteoarthritis (OA) and may be a target for intervention in randomized controlled trials. The potential benefit of therapeutic interventions in OA is likely enhanced if aimed at early stage disease. We have previously shown that knee effusion is associated with cartilage damage in early knee OA, but it is unknown whether knee effusion is associated with BML in early disease. Objectives To evaluate whether knee effusion on physical examination is associated with prevalent BML and with progression of BML over 3 years. Methods Population-based longitudinal cohort study of subjects, age 40-79, with knee pain. Subjects were evaluated at baseline and follow-up (mean 3.2 years) using standardized knee examination, fixed-flexion knee radiographs and MRI (1.5T). Only subjects with Kellgren-Lawrence (KL) radiographic grade 0-2 were included in this analysis. Knee effusion on examination was scored as present or absent. BML was scored on MRI on a 0-3 scale at 6 joint sites and the maximum score at any site was used in the analysis. Progression of BML was defined as worsening by ≥1 grade in those with BML 0-2 at baseline. Due to small numbers incidence and progression of BML could not be evaluated separately. MRI was read semi-quantitatively for cartilage damage (0-4 scale). Logistic regression analysis was used to evaluate the association of baseline knee effusion with BML prevalence and with BML progression. Analyses were adjusted for age, sex and body mass index. Results At baseline (n=199), mean age was 56 years, 50% were female and 16% had a knee effusion. KL grade 0, 1 and 2 was present in 50%, 28% and 22%, respectively. Cartilage damage on MRI was seen in 88%. BML was present in 79/199 subjects (40%). Of those with BML, 23/79 (29.1%) had effusion, compared to those without BML, where 8/120 (6.7%) had effusions. Knee effusion on examination was significantly associated with prevalent BML (OR 5.41, 95% CI 2.20-13.28). In this model, age was also significant with the risk of BML increased in those aged ≥50 years, compared to those aged 40-49 (OR 3.33, 95% CI 1.65-6.70). At follow-up (n=124), progression of BML was seen in 25/124 subjects (20.2%). Of these, 9/72 (12.5%) progressed from BML 0 to higher grades, while 16/52 (30.8%) progressed from BML 1 or 2 to higher grades. Baseline knee effusion was associated with a significant risk of progression of BML at 3 years (OR 3.02, 95% CI 1.01-9.01). Conclusions In this population-based cohort of early knee OA, the risk of prevalent BML and the risk of BML progression were both significantly increased in those with effusion compared to those without effusion on knee examination at baseline. Whether effusion is related to BML progression through common inflammatory signals or through other mechanisms requires further study. Evaluation for knee effusion may be a useful and inexpensive clinical test for potential identification of subjects with BML in clinical trials. Disclosure of Interest : None declared DOI 10.1136/annrheumdis-2014-eular.4840
    No preview · Article · Jun 2014 · Annals of the Rheumatic Diseases
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    ABSTRACT: Background Survey data provide important information on the prevalence of chronic conditions across different areas and population groups. In Canada, large national surveys routinely ask about physician-diagnosed arthritis. However, population data on osteoarthritis (OA) are limited, and there is virtually no information on self-reported, physician-diagnosed osteoarthritis of specific joints. Objectives The purpose of this study was to determine the prevalence of joint symptoms and self-reported, health professional diagnosed OA of different joints in a representative community sample of adults in the province of British Columbia (BC), Canada. Methods We carried out a mixed-method (mail and online) survey. A random sample of households was selected from a list of all residential addresses in BC. A variety of incentives were used to maximize response rates. One randomly selected person age 18+ per household was asked to complete the survey. We asked about joint pain or discomfort (using a homunculus) and a health professional diagnosis of OA in the knee, hip, hand, foot/ankle, lower back, and neck. In addition, demographic, general health, and healthcare utilization information was collected. Results Survey invitation letters were mailed to 7759 households and 2233 individuals completed an online (1778, 79.6%) or mailed (455, 20.4%) questionnaire. Of those, 45.8% were men, 38.8% were age 60+ and 19.9% were obese (BMI 30+). Joint pain/discomfort was reported by the following proportions of respondents: lower back - 48.8%, neck - 38.7%, knee - 34.7%, foot/ankle - 30.8%, hand - 30.5%, and hip - 24.2%. Joint pain/discomfort in the hand, hip and knee was more common on the right side, while foot pain was symmetrically distributed. Both sides were most often affected in the hands (51%) and least often in the hips (39%) and knees (40%). The most common site of OA was the knee - 10.1%, followed by lower back - 8.5%, neck - 5.5%, hand - 5.4%, hip - 4.2%, and foot - 3.1%. OA prevalence in any joint was 20.9% (15.7% if back/neck is excluded). OA prevalence was 12.2% when the diagnosis was restricted to those reporting any arthritis diagnosed by a health professional. The average age of OA diagnosis ranged from 52.4 years for the neck to 56.6 for the hip. Among those with OA, 43.4% (9.1% of all respondents) reported OA in multiple joint sites; 4.9% had OA in two sites, 2.4% in 3, and 1.7% in 4 or more. OA in one site was a strong predictor of OA in other sites. The strongest relationship was between hand and foot OA (odds ratio 25). In a multivariable logistic model older age and female sex were associated with higher OA prevalence, while education and income were not. Conclusions This is one of the first population surveys in Canada to report joint-specific prevalence of pain and self-reported health professional diagnosed OA in a large, geographically defined population. The most common OA site was the knee, but OA in the hand, hip and foot/ankle was also common. More than 40% had OA in multiple sites. Prevalence of OA in population surveys may be underestimated if the question about OA is asked only of those who report any arthritis. Disclosure of Interest : None declared DOI 10.1136/annrheumdis-2014-eular.2300
    No preview · Article · Jun 2014 · Annals of the Rheumatic Diseases

Publication Stats

4k Citations
611.53 Total Impact Points


  • 2003-2015
    • University of British Columbia - Vancouver
      • • School of Population and Public Health
      • • Department of Medicine
      Vancouver, British Columbia, Canada
    • Institute for Clinical Evaluative Sciences
      Toronto, Ontario, Canada
  • 2012-2014
    • National Surgical Adjuvant Breast and Bowel Project
      Pittsburgh, Pennsylvania, United States
  • 2000-2014
    • Arthritis Research Centre of Canada
      Ричмонд, British Columbia, Canada
  • 1996-2011
    • University of Toronto
      Toronto, Ontario, Canada
  • 2010
    • Vancouver General Hospital
      • Department of Radiology
      Vancouver, British Columbia, Canada
  • 2009
    • Simon Fraser University
      • Department of Statistics and Actuarial Sciences
      Burnaby, British Columbia, Canada
  • 2007
    • University of Pittsburgh
      Pittsburgh, Pennsylvania, United States
  • 1993-1995
    • McGill University
      • Department of Medicine
      Montréal, Quebec, Canada