Astrid Guttmann

Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada

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Publications (65)263.93 Total impact

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    ABSTRACT: Background International guidelines recommend patient education as an essential component of optimal asthma management. Since 1990 hospital-based asthma education centres (AECs) have been established in Ontario, Canada. It is unknown whether patient outcomes are related to the level of services provided.Methods Using linked, population-based health administrative and hospital survey data we analyzed a population of patients aged 2 to 55 years with a hospitalization for asthma (N¿=¿12 029) or a high acuity asthma emergency department (ED) visit (N¿=¿63 025) between April 2004 and March 2007 and followed for three years. Administrative data documenting individuals¿ attendance at AECs were not available. Poisson models were used to test the association of potential access to various AEC service models (outpatient service availability and in-hospital services) with asthma readmissions, ED visits or death within 6 to 36 months following the index admission or ED visit.ResultsFifty three of 163 acute care hospitals had an AEC (N¿=¿36) or had access by referral (N¿=¿17). All AECs documented use with guideline-based recommendations for AE programs. ED patients having access to an AEC that offered full-time, extended hours had reduced rates of adverse outcomes (adjusted relative rate [aRR] 0.78, 95% confidence interval [CI] 0.69, 0.90) compared to those with no AEC access. Hospitalized patients with access to asthma education during hospitalization had reduced rates of adverse events (aRR 0.87, 95% CI 0.75, 1.00) compared to those with no inhospital AEC access.Conclusion Although compliant with asthma guideline-based program elements, on a population basis access to asthma education centres is associated only with a modest benefit for some admitted and ED patients and depends on the level of access to services provided. Review of both services provided and strategies to address potential barriers to care are necessary.
    BMC Health Services Research 11/2014; 14(1):561. · 1.77 Impact Factor
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    ABSTRACT: The impact of socioeconomic status (SES) upon childhood cancer outcomes has not been extensively examined. Our objective was to determine the association between SES and event-free survival (EFS) among children with acute lymphoblastic leukemia (ALL) diagnosed in Ontario, Canada from 1995-2011 (N=1541) using Cox proportional hazards. Neither neighborhood-level median income quintile, distance from tertiary center, or rural residence significantly predicted EFS in the context of a universal healthcare system. Immigrant children experienced significantly superior EFS; confounding by ethnicity could not be ruled out. Confirmatory studies using additional individual-level SES variables are warranted.
    Leukemia Research 09/2014; · 2.76 Impact Factor
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    ABSTRACT: International cohort studies have reported increased incidence of inflammatory bowel disease (IBD) in recent years, and Canada has among the highest rates of IBD in the world. This study assessed incidence and prevalence of IBD in Ontario, the most populous province of Canada, to determine changing trends in age of onset.
    Inflammatory Bowel Diseases 08/2014; 20(10):1761-1769. · 5.12 Impact Factor
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    ABSTRACT: The cause of rising asthma incidence over time remains unexplained. Examining trends in the age of diagnosis across successive birth cohorts may offer insights into asthma etiology.
    The Journal of allergy and clinical immunology. 06/2014;
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    ABSTRACT: Health administrative databases can be used to track disease incidence, outcomes, and care quality. Case validation is necessary to ensure accurate disease ascertainment using these databases. In this study, we aimed to validate adult-onset inflammatory bowel disease (IBD) identification algorithms. We used two large cohorts of incident patients from Ontario, Canada to validate algorithms. We linked information extracted from charts to health administrative data and compared the accuracy of various algorithms. In addition, we validated an algorithm to distinguish patients with Crohn's from those with ulcerative colitis and assessed the adequate look-back period to distinguish incident from prevalent cases. Over 5,000 algorithms were tested. The most accurate algorithm to identify patients 18 to 64 years at diagnosis was five physician contacts or hospitalizations within 4 years (sensitivity, 76.8%; specificity, 96.2%; positive predictive value (PPV), 81.4%; negative predictive value (NPV), 95.0%). In patients ≥65 years at diagnosis, adding a pharmacy claim for an IBD-related medication improved accuracy. Patients with adult-onset incident IBD can be accurately identified from within health administrative data. The validated algorithms will be applied to administrative data to expand the Ontario Crohn's and Colitis Cohort to all patients with IBD in the province of Ontario.
    Journal of clinical epidemiology 04/2014; 67(8):887-896. · 5.48 Impact Factor
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    ABSTRACT: Cerebral palsy (CP) has a multifactorial etiology, and placental vascular disease may be one major risk factor. The risk of placental vascular disease may be lower among some immigrant groups. We studied the association between immigrant status and the risk of CP.
    PLoS ONE 01/2014; 9(7):e102275. · 3.53 Impact Factor
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    ABSTRACT: While low socioeconomic status (SES) has been associated with inferior cancer outcome among adults, its impact in pediatric oncology is unclear. Our objective was therefore to conduct a systematic review to determine the impact of SES upon outcome in children with cancer. We searched Ovid Medline, EMBASE and CINAHL from inception to December 2012. Studies for which survival-related outcomes were reported by socioeconomic subgroups were eligible for inclusion. Two reviewers independently assessed articles and extracted data. Given anticipated heterogeneity, no quantitative meta-analyses were planned a priori. Of 7,737 publications, 527 in ten languages met criteria for full review; 36 studies met final inclusion criteria. In low- and middle-income countries (LMIC), lower SES was uniformly associated with inferior survival, regardless of the measure chosen. The majority of associations were statistically significant. Of 52 associations between socioeconomic variables and outcome among high-income country (HIC) children, 38 (73.1%) found low SES to be associated with worse survival, 15 of which were statistically significant. Of the remaining 14 (no association or high SES associated with worse survival), only one was statistically significant. Both HIC studies examining the effect of insurance found uninsured status to be statistically associated with inferior survival. Socioeconomic gradients in which low SES is associated with inferior childhood cancer survival are ubiquitous in LMIC and common in HIC. Future studies should elucidate mechanisms underlying these gradients, allowing the design of interventions mediating socioeconomic effects. Targeting the effect of low SES will allow for further improvements in childhood cancer survival.
    PLoS ONE 01/2014; 9(2):e89482. · 3.53 Impact Factor
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    ABSTRACT: Study objective In recent years, lean principles have been applied to improve wait times in the emergency department (ED). In 2009, an ED process improvement program based on lean methods was introduced in Ontario as part of a broad strategy to reduce ED length of stay and improve patient flow. This study seeks to determine the effect of this program on ED wait times and quality of care. Methods We conducted a retrospective cohort study of all ED visits at program and control sites during 3 program waves from April 1, 2007, to June 30, 2011, in Ontario, Canada. Time series analyses of outcomes before and after the program and difference-in-differences analyses comparing changes in program sites with control sites were conducted. Results In before-after models among program sites alone, 90th percentile ED length of stay did not change in wave 1 (–14 minutes [95% confidence interval {CI} –47 to 20]) but decreased after wave 2 (–87 [95% CI –108 to –66]) and wave 3 (–33 [95% CI –50 to –17]); median ED length of stay decreased after wave 1 (–18 [95% CI –24 to –12]), wave 2 (–23 [95% CI –27 to –19]), and wave 3 (–15 [95% CI –18 to –12]). In all waves, decreases were observed in time to physician assessment, left-without-being-seen rates, and 72-hour ED revisit rates. In the difference-in-difference models, in which changes in program sites were compared with controls, the program was associated with no change in 90th percentile ED length of stay in wave 2 (17 [95% CI –0.2 to 33]) and increases in wave 1 (23 [95% CI 0.9 to 45]) and wave 3 (31 [95% CI 10 to 51]), modest reductions in median ED length of stay in waves 2 and 3 alone, and a decrease in time to physician assessment in wave 3 alone. Conclusion Although the program reduced ED waiting times, it appeared that its benefits were diminished or disappeared when compared with that of control sites, which were exposed to system-wide initiatives such as public reporting and pay for performance. This study suggests that further evaluation of the effectiveness of lean methods in the ED is warranted before widespread implementation.
    BMC Health Services Research 01/2014; · 1.77 Impact Factor
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    ABSTRACT: Care giving for children with chronic diseases can lead to financial strain and compromised family well being. Little is known about whether these stresses lead to changes in residential movement patterns as they relate to income adequacy and proximity to care. We compared the residential movement patterns and associated changes in neighbourhood income of children with mild to severe chronic diseases compared with those that are healthy. A cohort of infants born from 2002--2007 in Ontario, Canada was followed for 5 years and divided into those with single- or multiple- body system complex chronic conditions (CCCs); low birth weight (LBW); asthma/recurrent wheeze (A/RW) and the control group of otherwise healthy children. Of 598,716 children studied, 15,207 had a single CCC, 3,600 multiple CCCs, 33,206 LBW, 57,137 A/RW and 489,566 were healthy. Lowest income quintile children were most likely to move residence. Compared with healthy controls, chronic disease cohorts, apart from those with asthma, were more likely to be born in the lowest income quintile neighbourhood and to move. Among children who moved, all chronic disease cohorts were significantly more likely to move to a low income quintile neighborhood (adjusted odds ratios for all chronic disease cohorts of 1.1-1.2). There were no differences across cohorts in residential movement close to a children's hospital. Young children with chronic conditions, particularly those born in low income neighbourhoods, are more likely to move residence than other healthy young children. However, it does not seem that proximity to specialized care is driving this movement. Further research is required to determine if these movement patterns impact the ability of children with chronic conditions to secure health services.
    International Journal for Equity in Health 08/2013; 12(1):62. · 1.71 Impact Factor
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    ABSTRACT: BACKGROUND: Administrative databases and cancer registries are frequently used to conduct population-based research, but often lack clinical data necessary for risk stratification. Our objective was to determine the criterion validity of a risk-stratification algorithm based on treatment characteristics available from a pediatric cancer registry as a proxy for disease risk, by comparing it to traditional biology-based risk classifications. METHODS: We identified all children with acute lymphoblastic leukemia diagnosed at a single institution between January 2000 and June 2011, and linked them to a population-based cancer registry. Several risk algorithms were then constructed using disease risk variables collected through chart review by a pediatric oncologist, and compared to a risk algorithm based on treatment protocol name and age, available from the registry. RESULTS: Of 596 patients identified, 579 (97.1%) met inclusion criteria and were successfully linked. The registry-based algorithm showed almost perfect agreement with a biology-based algorithm based on age, initial white blood cell count, immunophenotype and cytogenetics (kappa=0.85, 95th confidence interval 0.81-0.90). Discrepant cases were often due to the presence of unusual high risk features not captured by standard disease-risk variables but reflected in clinicians' choices of higher intensity treatment protocols. CONCLUSIONS: Protocol name represents a valid proxy of disease risk, allowing for risk stratification while conducting comparative effectiveness research using cancer registries and health services data. Future studies should examine the validity of treatment-based risk algorithms in other malignancies and using other treatment characteristics commonly found in health services data, such as the receipt of specific chemotherapeutic agents.
    BMC Medical Research Methodology 05/2013; 13(1):68. · 2.21 Impact Factor
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    ABSTRACT: INTRODUCTION: This study aimed to determine the effectiveness of seasonal influenza vaccine in pre- and full-term children aged 6-23 months. METHODS: We examined a cohort of 683,354 young children (7.7% preterm) over five influenza seasons (2004-2005 to 2008-2009) in Ontario, Canada. Vaccine effectiveness was estimated using influenza-coded ambulatory visits during virologically-confirmed influenza season periods as the outcome and multivariable Cox proportional hazards modeling. RESULTS: Full vaccination was associated with a 19% reduction in influenza-coded ambulatory visits (HR=0.81; 95% CI, 0.68-0.97) in all children, and an 18% reduction in full-term children (HR=0.82; 95% CI, 0.68-0.99). We did not find significant vaccine effectiveness for preterm children. No benefit was found for partial vaccination. CONCLUSIONS: In children younger than two years, only full influenza vaccination is associated with reduced influenza-coded ambulatory visits. Since the effectiveness of influenza vaccination in preterm children remains uncertain, further study of this highly vulnerable population is warranted.
    Vaccine 05/2013; · 3.77 Impact Factor
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    ABSTRACT: Objective: A significant decline in the prevalence of neural tube defects (NTD) through food fortification has been reported. Questions remain, however, about the effectiveness of this intervention in reducing the gap in prevalence across socioeconomic status (SES). Study Design: Using health number and through record linkage, children born in Ontario hospitals between 1994 and 2009 were followed for the diagnosis of congenital anomalies. SES quintiles were assigned to each child using census information at the time of birth. Adjusted rates and multivariate models were used to compare trends among children born in different SES groups. Results: Children born in low SES areas had significantly higher rates of NTDs (RR = 1.25, CI: 1.14-1.37). Prevalence of NTDs among children born in low and high SES areas declined since food fortification began in 1999 although has started rising again since 2006. While the crude decline was greater in low SES areas, after adjustment for maternal age, the slope of decline and SES gap in prevalence rates remained unchanged overtime. Conclusions: While food fortification is successful in reducing the prevalence of NTDs, it was not associated with removing the gap between high and low SES groups.
    International Journal of Environmental Research and Public Health 01/2013; 10(4):1312-23. · 2.00 Impact Factor
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    Clinical Epidemiology 01/2013; 5:29-31.
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    ABSTRACT: BACKGROUND AND OBJECTIVE:Health care use of children with medical complexity (CMC), such as those with neurologic impairment or other complex chronic conditions (CCCs) and those with technology assistance (TA), is not well understood. The objective of the study was to evaluate health care utilization and costs in a population-based sample of CMC in Ontario, Canada.METHODS:Hospital discharge data from 2005 through 2007 identified CMC. Complete health system use and costs were analyzed over the subsequent 2-year period.RESULTS:The study identified 15 771 hospitalized CMC (0.67% of children in Ontario); 10 340 (65.6%) had single-organ CCC, 1063 (6.7%) multiorgan CCC, 4368 (27.6%) neurologic impairment, and 1863 (11.8%) had TA. CMC saw a median of 13 outpatient physicians and 6 distinct subspecialists. Thirty-six percent received home care services. Thirty-day readmission varied from 12.6% (single CCC without TA) to 23.7% (multiple CCC with TA). CMC accounted for almost one-third of child health spending. Rehospitalization accounted for the largest proportion of subsequent costs (27.2%), followed by home care (11.3%) and physician services (6.0%). Home care costs were a much larger proportion of costs in children with TA. Children with multiple CCC with TA had costs 3.5 times higher than children with a single CCC without TA.CONCLUSIONS:Although a small proportion of the population, CMC account for a substantial proportion of health care costs. CMC make multiple transitions across providers and care settings and CMC with TA have higher costs and home care use. Initiatives to improve their health outcomes and decrease costs need to focus on the entire continuum of care.
    PEDIATRICS 11/2012; · 4.47 Impact Factor
  • Eric I Benchimol, Sinead Langan, Astrid Guttmann
    Journal of clinical epidemiology 11/2012; · 5.48 Impact Factor
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    ABSTRACT: OBJECTIVE To determine whether children treated in emergency departments (EDs) with evidence-based standardized protocols (EBSPs) containing evidence-based content and format had lower risk of hospital admission or ED return visit and greater follow-up than children treated in EDs with no standardized protocols in Ontario, Canada. DESIGN Retrospective population-based cohort study of children with asthma. We used multivariable logistic regression to estimate risk of outcomes. SETTING All EDs in Ontario (N = 146) treating childhood asthma from April 2006 to March 2009. PARTICIPANTS Thirty-one thousand one hundred thirty-eight children (aged 2 to 17 years) with asthma. MAIN EXPOSURE Type of standardized protocol (EBSPs, other standardized protocols, or none). MAIN OUTCOME MEASURES Hospital admission, high-acuity 7-day return visit to the ED, and 7-day outpatient follow-up visit. RESULTS The final cohort made 46 510 ED visits in 146 EDs. From the index ED visit, 4211 (9.1%) were admitted to the hospital. Of those discharged, 1778 (4.2%) and 7350 (17.4%) had ED return visits and outpatient follow-up visits, respectively. The EBSPs were not associated with hospitalizations, return visits, or follow-up (adjusted odds ratio, 1.17 [95% CI, 0.91-1.49]; adjusted odds ratio, 1.10 [95% CI, 0.86-1.41]; and adjusted odds ratio, 1.08 [95% CI, 0.87-1.35], respectively). CONCLUSIONS The EBSPs were not associated with improvements in rates of hospital admissions, return visits to the ED, or follow-up. Our findings suggest the need to address gaps linking improved processes of asthma care with outcomes.
    JAMA Pediatrics 07/2012; 166(9):834-40. · 4.28 Impact Factor
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    ABSTRACT: To evaluate the effect of emergency department (ED) clinical decision units (CDUs) on overall ED patient flow in a pilot project funded in 2008 by the Ontario Ministry of Health and Long-Term Care (MOHLTC). A retrospective analysis of unscheduled ED visits at seven CDU pilot and nine control sites was conducted using administrative data. The authors examined trends in CDU utilization and compared outcomes between pilot-CDU and control sites 1 year prior to implementation, with the first 18 months of CDU operation. Sites that were unsuccessful in their applications for CDU program funding served as controls. Outcomes included ED length of stay (LOS), admission rates, and ED revisit rates. At CDU sites, roughly 4% of ED patients were admitted to CDUs. The presence of a pilot-CDU was independently associated with a small reduction in ED LOS for all low-acuity patients (-0.14 hour, 95% confidence interval [CI]=-0.22 to -0.07) and nonadmitted patients (-0.11 hour, 95% CI=-0.16 to -0.07). A small independent effect on absolute hospital admission rate for all high-acuity patients (-0.8%, 95% CI=-1.5% to -0.03%) and moderate-acuity patients (-0.6%, 95% CI=-1.1% to -0.2%) was also observed. Pilot-CDUs were not associated with changes in ED revisit rates. With only 4% of ED patients admitted to CDUs, the potential for efficiency gains in these EDs was limited. Nonetheless, these findings suggest small improvements in the operation of the ED through CDU implementation. Although marginal, the observed effects of CDU operation were in the desired direction of reduced ED LOS, reduced admission rate, and no increase in ED revisit rate.
    Academic Emergency Medicine 07/2012; 19(7):828-36. · 2.20 Impact Factor
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    ABSTRACT: The role of public reporting in improving hospital quality of care is controversial. Reporting of hospital-acquired infection rates has been introduced in multiple health care systems, but its relationship to infection rates has been understudied. Our objective was to determine whether mandatory public reporting by hospitals is associated with a reduction in hospital rates of Clostridium difficile infection. We conducted a longitudinal, population-based cohort study in Ontario (Canada's largest province) between April 1, 2002, and March 31, 2010. We included all patients (>1 y old) admitted to 180 acute care hospitals. Using Poisson regression, we developed a model to predict hospital- and age-specific monthly rates of C. difficile disease per 10,000 patient-days prior to introduction of public reporting on September 1, 2008. We then compared observed monthly rates of C. difficile infection in the post-intervention period with rates predicted by the pre-intervention predictive model. In the pre-intervention period there were 33,634 cases of C. difficile infection during 39,221,113 hospital days, with rates increasing from 7.01 per 10,000 patient-days in 2002 to 10.79 in 2007. In the first calendar year after the introduction of public reporting, there was a decline in observed rates of C. difficile colitis in Ontario to 8.92 cases per 10,000 patient-days, which was significantly lower than the predicted rate of 12.16 (95% CI 11.35-13.04) cases per 10,000 patient-days (p<0.001). Over this period, public reporting was associated with a 26.7% (95% CI 21.4%-31.6%) reduction in C. difficile cases, or a projected 1,970 cases averted per year (95% CI 1,476-2,500). The effect was specific to C. difficile, with rates of community-acquired gastrointestinal infections and urinary tract infections unchanged. A limitation of our study is that this observational study design cannot rule out the influence of unmeasured temporal confounders. Public reporting of hospital C. difficile rates was associated with a substantial reduction in the population burden of this infection. Future research will be required to discern the direct mechanism by which C. difficile infection rates may have been reduced in response to public reporting. Please see later in the article for the Editors' Summary.
    PLoS Medicine 07/2012; 9(7):e1001268. · 15.25 Impact Factor
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    ABSTRACT: To determine physician-administered influenza vaccine coverage for children aged 6 to 23 months in a jurisdiction with a universal influenza immunization program during 2002-2009 and to describe predictors of vaccination. By using hospital records, we identified all infants born alive in Ontario hospitals from April 2002 through March 2008. Immunization status was ascertained by linkage to physician billing data. Children were categorized as fully, partially, or not immunized depending on the number and timing of vaccines administered. Generalized linear mixed models determined the association between immunization status and infant, physician, and maternal characteristics. Influenza immunization was low for the first influenza season of the study period (1% fully immunized during the 2002-2003 season), increased for the following 3 seasons (7% to 9%), but then declined (4% to 6% fully immunized during the 2006-2007 to 2008-2009 seasons). Children with chronic conditions or low birth weight were more likely to be immunized. Maternal influenza immunization (adjusted odds ratio 4.31; 95% confidence interval 4.21-4.40), having a pediatrician as the primary care practitioner (adjusted odds ratio 1.85; 95% confidence interval 1.68-2.04), high visit rates, and better continuity of care were all significantly associated with full immunization, whereas measures of social disadvantage were associated with nonimmunization. Low birth weight infants discharged from neonatal care in the winter were more likely to be immunized. Influenza vaccine coverage among children aged 6 to 23 months in Ontario is low, despite a universal vaccination program and high primary care visit rates. Interventions to improve coverage should target both physicians and families.
    PEDIATRICS 05/2012; 129(6):e1421-30. · 4.47 Impact Factor
  • Patricia Li, Teresa To, Astrid Guttmann
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    ABSTRACT: To describe the follow-up care within 28 days of an emergency department (ED) visit for asthma and to determine the association of follow-up visits within 28 days with ED re-visits and hospital admissions in the subsequent year. Population-based retrospective cohort study of children with asthma aged 2-17 years treated in an ED in Ontario, Canada between April 14, 2006 and February 28, 2009. Multiple linked health administrative datasets and Cox proportional hazard multivariable survival models were used to test the association of characteristics of 28-day follow-up visits with 1-year outcomes. The final cohort consisted of 29391 children, of whom 32.8% had follow-up, 6496 (22.1%) had an ED re-visit, and 801 (2.7%) had a hospital admission. Having a follow-up visit was not associated with ED re-visit or hospitalizations (hazard ratio 0.98; 95% CI 0.93, 1.03 and hazard ratio 1.06; 95% CI 0.92, 1.23, respectively). Younger children and those with indices of more severe acute or chronic asthma were more likely to have ED re-visits and hospitalizations. Other follow-up care characteristics (number of visits, type of physician providing care) were not associated with outcomes. Despite a universal healthcare setting, most children did not access follow-up care after an ED visit for asthma, and those that did had no associated benefit in terms of reduced ED re-visits and hospitalizations in the subsequent year.
    The Journal of pediatrics 04/2012; 161(2):208-13.e1. · 4.02 Impact Factor

Publication Stats

616 Citations
263.93 Total Impact Points

Institutions

  • 2004–2014
    • Institute for Clinical Evaluative Sciences
      Toronto, Ontario, Canada
  • 2001–2014
    • SickKids
      Toronto, Ontario, Canada
    • Sunnybrook Health Sciences Centre
      • Department of Evaluative Clinical Sciences
      Toronto, Ontario, Canada
  • 2012
    • University of Ottawa
      Ottawa, Ontario, Canada
    • McGill University
      • Department of Pediatrics
      Montréal, Quebec, Canada
  • 2009
    • Alberta Health Services
      • Department of Pediatrics
      Calgary, Alberta, Canada
  • 2007–2009
    • University of Toronto
      • • Hospital for Sick Children
      • • Department of Paediatrics
      Toronto, Ontario, Canada