Institute for Clinical Evaluative SciencesON

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Institute for Clinical Evaluative SciencesON

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Fleet J.L.,University of Western Ontario | Fleet J.L.,Institute for Clinical Evaluative SciencesON | Weir M.A.,University of Western Ontario | McArthur E.,Institute for Clinical Evaluative SciencesON | And 8 more authors.
American Journal of Kidney Diseases | Year: 2014

Background Atenolol and metoprolol tartrate are commonly prescribed β-blockers. Atenolol elimination depends on kidney function, whereas metoprolol tartrate does not. We hypothesized that compared to metoprolol tartrate, initiating oral atenolol treatment would be associated with more adverse events in older adults, with the association most pronounced in patients with lower baseline estimated glomerular filtration rates (eGFRs).Study Design Population-based matched retrospective cohort study.Setting & Participants Older adults (mean age, 75 years) in Ontario, Canada, prescribed oral atenolol versus metoprolol tartrate from April 2002 through December 2011. The 2 groups were well matched (n = 75,257 in each group), with no difference in 31 measured baseline characteristics. Patients with end-stage renal disease were ineligible, and 4.6% of patients had chronic kidney disease (median eGFR, 38 mL/min/1.73 m2 assessed through a database algorithm).Predictors β-Blocker type and eGFR.Outcomes A composite outcome of hospitalization with bradycardia or hypotension and all-cause mortality were assessed in 90-day follow-up.Results Compared to metoprolol tartrate, initiating atenolol treatment was not associated with higher risk of hospitalization with bradycardia or hypotension (incidence, 0.71% vs 0.79%; relative risk, 0.90; 95% CI, 0.80-1.01). Atenolol treatment initiation was associated with lower 90-day risk of mortality than metoprolol tartrate (incidence, 0.97% vs 1.44%; relative risk, 0.68; 95% CI, 0.61-0.74). Lower eGFR did not modify either association (P for interaction = 0.5 and 0.6, respectively).Limitations Heart rate and blood pressure were not available in our data sources, and effects ascertained from observational studies are subject to residual confounding.Conclusions Contrary to our expectation, we found that atenolol versus metoprolol tartrate was associated with lower 90-day risk of mortality in patients regardless of eGFR, with no difference in risk of hospitalization with bradycardia or hypotension. © 2014 National Kidney Foundation, Inc.


Belley-Cote E.P.,McMaster University | Parikh C.R.,Yale University | Shortt C.R.,McMaster University | Coca S.G.,Mount Sinai School of Medicine | And 16 more authors.
Journal of Thoracic and Cardiovascular Surgery | Year: 2016

Objective Acute kidney injury is common after cardiac surgery and associated with postoperative mortality. Perioperative cardiac biomarkers may predict acute kidney injury and mortality. We evaluated whether cardiac biomarkers were associated with severe acute kidney injury, defined as a doubling in serum creatinine or requiring renal replacement therapy during hospital stay after surgery, and mortality. Methods In a prospective multicenter cohort of adults undergoing cardiac surgery, we measured the following biomarkers in preoperative and postoperative banked plasma: High-sensitivity troponin T, cardiac troponin I, creatine kinase-MB, and N-terminal prohormone of brain natriuretic peptide. Results In the patients who were discharged alive, severe acute kidney injury occurred in 37 of 960 (3.9%), and 43 of 960 (4.5%) died within 1 year of follow-up. N-terminal prohormone of brain natriuretic peptide was the only preoperative biomarker that was independently associated with severe acute kidney injury (with log transformation, adjusted odds ratio, 1.4; 95% confidence interval, 1.0-1.9). Biomarkers measured within 6 hours of surgery (day 1) were all associated with severe acute kidney injury. Preoperative N-terminal prohormone of brain natriuretic peptide was also independently associated with 1-year mortality (with log transformation, adjusted odds ratio, 1.7; 95% confidence interval, 1.2-2.2). Patients in the highest tertile for N-terminal prohormone of brain natriuretic peptide preoperatively (>1006.4 ng/L) had marked increases in their risk for 1-year mortality (adjusted odds ratio, 27.2; 95% confidence interval, 3.5-213.5). Day 1 N-terminal prohormone of brain natriuretic peptide was associated with mortality independently of change in serum creatinine from preoperative baseline. Conclusions Of the studied biomarkers, N-terminal prohormone of brain natriuretic peptide was the only preoperative biomarker independently associated with severe acute kidney injury and mortality. Early increases in postoperative cardiac biomarkers were associated with severe acute kidney injury after cardiac surgery. Future research should focus on whether interventions that lower N-terminal prohormone of brain natriuretic peptide can affect postoperative outcomes. © 2016 The American Association for Thoracic Surgery.


Mahar A.L.,Queen's University | Coburn N.G.,Institute for Clinical Evaluative SciencesON | Coburn N.G.,Odette Cancer Center | Johnson A.P.,Queen's University | Johnson A.P.,Institute for Clinical Evaluative SciencesON
Lung Cancer | Year: 2014

Objectives: Surgical resection and adjuvant chemotherapy have become standard of care for treating resectable early stage non-small cell lung cancer (NSCLC). The purpose was to describe and compare the overall and regional resource utilization and costs of resected NSCLC treated with and without adjuvant chemotherapy. Materials & Methods: A population-based retrospective cohort study of resected NSCLC patients, diagnosed between 2004 and 2006 (representing the cohort immediately affected by the change in clinical practice) was performed using administrative data. Patients were followed for four years from the date of surgery. The healthcare system perspective was used, and cost estimates (2012 US$) were derived from administrative data and the literature. Results: 3354 patients were included. The average cost per patient treated with surgery and adjuvant chemotherapy was $37,860.88 and was significantly higher than the average cost per patient treated with surgery alone $32,221.45 (. p<. 0.0001). Among regions, the costs of patients treated with surgery and chemotherapy ($32,672-$45,453) and the costs of those treated with surgery alone ($28,679-$36,845) varied significantly (. p<. 0.0001). Rates of chemotherapy, the proportion of patients who received any imaging scans, hospitalizations, specialist visits, emergency room visits, mean number of imaging scans, general physician visits, and blood transfusions all varied significantly among geographic regions. Conclusions: This population-based study demonstrates an average cost per patient similar to that shown in randomized controlled trials; however, costs for either treatment approach varied by geographic region. Understanding the regional variation in costs and resource utilization is important with respect to delivering optimal treatment in a cost-effective strategy. © 2014.


Wijeysundera H.C.,University of Toronto | Wijeysundera H.C.,Institute for Clinical Evaluative SciencesON | Wijeysundera H.C.,Li Ka Shing Knowledge Institute | Sidhu M.S.,Albany Medical College | And 8 more authors.
Circulation: Cardiovascular Interventions | Year: 2016

Background - Although an invasive strategy is a class I clinical practice guideline for non-ST-segment-elevation acute coronary syndromes, there is wide variation in the proportion of patients who undergo revascularization despite early angiography. We sought to identify the predictors of early revascularization versus medical therapy alone in patients with non-ST-segment-elevation acute coronary syndrome undergoing an invasive strategy and to assess their clinical outcomes. Methods and Results - We assessed revascularization status by percutaneous coronary intervention or coronary artery bypass grafting within 7 days of the index angiogram in all patients with non-ST-segment-elevation acute coronary syndrome who underwent an invasive strategy in Ontario, Canada, from October 1, 2008, to October 31, 2013, with follow-up through December 31, 2014. The primary outcome was mortality. Multivariable hierarchical logistic models identified predictors of revascularization, and multivariable Cox models with treatment strategy as a 3-level time-varying covariate assessed the relationship between revascularization status and clinical outcomes. We identified 50 302 patients of whom 34 288 (68.2%) underwent revascularization (percutaneous coronary intervention: 28 011 and coronary artery bypass grafting: 6277). There was a 2-fold variation in revascularization rates across hospitals. A higher risk presentation significantly predicted revascularization (odds ratio, 1.26; 95% confidence interval, 1.18-1.35), as did having the angiogram by an interventional cardiologist (odds ratio, 1.76; 95% confidence interval, 1.57-1.98). Revascularized patients with either percutaneous coronary intervention (hazard ratio, 0.64; 95% confidence interval, 0.60-0.69) or coronary artery bypass grafting (hazard ratio, 0.53; 95% confidence interval, 0.47-0.60) had improved survival compared with medically treated patients. Conclusions - Although the majority of patients with non-ST-segment-elevation acute coronary syndrome who underwent an early invasive approach received revascularization, there was wide variation. Revascularization was associated with significantly improved survival. © 2016 American Heart Association, Inc.


Stergiou-Kita M.,University of Toronto | Bayley M.,University of Toronto | Cassidy J.D.,University of Western Ontario | Cassidy J.D.,University of Toronto | And 13 more authors.
Journal of Burn Care and Research | Year: 2014

The objective of this study was to gain an understanding of workers' experiences with returning to work, the challenges they experienced, and the supports they found most beneficial when returning to work after a workplace electrical injury. Thirteen semistructured qualitative telephone interviews were conducted with individuals who experienced an electrical injury at the workplace. Participants were recruited from specialized burns rehabilitation programs in Ontario, Canada. Interviews were transcribed verbatim and thematic analysis used to analyze the qualitative interviews. Data regarding workers' demographics, injury events, and occupational categories were also gathered to characterize the sample.Participants identified three distinct categories of challenges: 1) physical, cognitive, and psychosocial impairments and their effects on their work performance; 2) feelings of guilt, blame, and responsibility for the injury; and 3) having to return to the workplace or worksite where the injury took place. The most beneficial supports identified by the injured workers included: 1) support from family, friends, and coworkers; and 2) the receipt of rehabilitation services specialized in electrical injury. The most common advice to others after electrical injuries included: 1) avoiding electrical injury; 2) feeling ready to return to work; 3) filing a Workplace Safety and Insurance Board injury/ claims report;4) proactive self-advocacy; and 5) garnering the assistance of individuals who understood electrical injuries to advocate on their behalf. Immediate and persistent physical, cognitive, psychosocial, and support factors can affect individuals' abilities to successfully return to work after an electrical injury. Specialized services and advocacy were viewed as beneficial to successful return to work. Copyright © 2014 by the American Burn Association.


Clemens K.K.,University of Western Ontario | Shariff S.,Institute for Clinical Evaluative SciencesON | Liu K.,Institute for Clinical Evaluative SciencesON | Hramiak I.,University of Western Ontario | And 4 more authors.
PLoS ONE | Year: 2015

Background: Over the last decade, several new antihyperglycemic medications have been introduced including those associated with a lower hypoglycemia risk. We aimed to investigate how these medications are being prescribed to older adults in our region. Methods: We conducted population-based cross-sectional analyses of older adults (mean age 75 years) with treated diabetes in Ontario, Canada from 2002 until 2013, to examine the percentage prescribed insulin, sulphonylureas, alpha-glucosidase inhibitors, metformin, thiazolidinediones, meglitinides, and dipeptidyl peptidase-4 inhibitors. Over the study period, we also examined their hospital encounters for hypoglycemia (emergency room or inpatient encounter). Results: The mean age of treated patients increased slightly over the study quarters and the proportion that were women declined. With the exception of chronic kidney disease, cancer, dementia, and neuropathy, the percentage with a comorbidity appeared to decline. The percentage of treated patients prescribed metformin, gliclazide and dipeptidyl peptidase-4 inhibitors increased as did combination therapy. Glyburide and thiazolidinedione prescriptions declined, and insulin use remained stable. In those with newly treated diabetes, the majority were prescribed metformin, with smaller percentages prescribed insulin and other oral agents. Although the absolute number of treated patients with a hypoglycemia encounter increased until mid-2006 and then decreased, the overall percentage with an encounter declined over the study period (0.8% with an event in the first quarter, 0.4% with an event in the last quarter). Conclusions: Antihyperglycemic medications with safer profiles are being increasingly prescribed to older adults. In this setting there has been a decrease in the percentage of treated patients with a hospital encounter for hypoglycemia. © 2015 Clemens et al.


Li A.H.-T.,University of Western Ontario | Lam N.N.,University of Western Ontario | Naylor K.L.,University of Western Ontario | Garg A.X.,University of Western Ontario | And 4 more authors.
Transplantation | Year: 2016

Background. Solid organ transplantation is the preferred treatment for patients with end-stage organ failure. Although much progress has been made over the past decade, some patients still require early readmission after their initial hospital discharge. Early hospital readmission is an important metric for health care quality. It is often measured in nontransplant medical and surgical conditions but has only recently been applied to organ transplantation.Methods.We performed a structured MEDLINE search to retrieve, review, and summarize original studies on the incidence, risk factors, outcomes, and prevention of early hospital readmissions after kidney, liver, and kidney-pancreas transplantation. Early hospital readmission was defined as readmission to hospital within 30 days of discharge from the transplant hospitalization. Results. The risk of early readmission varies by organ type, (highest in liver transplants and lowest in kidney transplants). Causes for early hospital readmission are most commonly due to surgical, immunologic, or infectious complications. Risk factors associated with early hospital readmission often reflect pretransplant comorbidity, andmany of these factors may not be modifiable. Early hospital readmission is also associated with decreased graft and patient survival.Conclusions. Early hospital readmission after transplantation is common and associated with adverse outcomes. The potential for preventing early hospital readmissions and the impact on patient outcomes remain unclear. Current evidence suggests that some, but not all, early hospital readmissions after transplantation may be prevented. © 2016 Wolters Kluwer Health, Inc. All rights reserved.


Jinapriya D.,Queen's University | D'Souza M.,Queen's University | Hollands H.,Queen's University | El-Defrawy S.R.,Queen's University | And 10 more authors.
Ophthalmology | Year: 2014

Purpose: To investigate the effect of anti-inflammatory therapy on selective laser trabeculoplasty (SLT) outcomes. Design: Randomized, double-masked, placebo-controlled trial. Participants: Patients with primary open-angle or pseudo-exfoliation glaucoma. Methods: Patients undergoing SLT were randomized to receive placebo (artificial tears), prednisolone acetate 1%, or ketorolac tromethamine 0.5% eye drops 4 times per day for 5 days commencing immediately after SLT. Main Outcome Measures: Change in intraocular pressure (IOP) from baseline to the 1-month post-SLT visit. Results: Mean change in IOP at the 1-month primary outcome time point, as well as all other time points, was not significantly different among groups (P = 0.99). Likewise, a repeated-measures, mixed-effects model did not find significant differences in IOP outcome at the 1-month time point (P = 0.95). The IOP was reduced in all groups at the 1-month post-SLT time point and all other time points, and no significant differences were found between groups using separate unadjusted cross-sectional analyses of variance (P > 0.15 for analyses at all time points). Treatment failure rates were not different among groups (P = 0.75), and at 1 year after SLT, the percentage of patients maintaining a 20% IOP reduction ranged from 18% to 22% in the 3 study groups. Conclusions: Anti-inflammatory therapy after SLT does not seem to substantially influence the IOP-lowering effect of SLT. In this study of patients with low baseline IOP, SLT showed limited efficacy in achieving a sustained reduction in IOP. © 2014 American Academy of Ophthalmology.

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