12 results on '"Alter DA"'
Search Results
2. Effect of cardiac rehabilitation referral strategies on utilization rates: a prospective, controlled study.
- Author
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Grace SL, Russell KL, Reid RD, Oh P, Anand S, Rush J, Williamson K, Gupta M, Alter DA, Stewart DE, and Cardiac Rehabilitation Care Continuity Through Automatic Referral Evaluation (CRCARE) Investigators
- Published
- 2011
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3. Effectiveness of public report cards for improving the quality of cardiac care: the EFFECT study: a randomized trial.
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Tu JV, Donovan LR, Lee DS, Wang JT, Austin PC, Alter DA, Ko DT, Tu, Jack V, Donovan, Linda R, Lee, Douglas S, Wang, Julie T, Austin, Peter C, Alter, David A, and Ko, Dennis T
- Abstract
Context: Publicly released report cards on hospital performance are increasingly common, but whether they are an effective method for improving quality of care remains uncertain.Objective: To evaluate whether the public release of data on cardiac quality indicators effectively stimulates hospitals to undertake quality improvement activities that improve health care processes and patient outcomes.Design, Setting, and Patients: Population-based cluster randomized trial (Enhanced Feedback for Effective Cardiac Treatment [EFFECT]) of 86 hospital corporations in Ontario, Canada, with patients admitted for acute myocardial infarction (AMI) or congestive heart failure (CHF).Intervention: Participating hospital corporations were randomized to early (January 2004) or delayed (September 2005) feedback of a public report card on their baseline performance (between April 1999 and March 2001) on a set of 12 process-of-care indicators for AMI and 6 for CHF. Follow-up performance data (between April 2004 and March 2005) also were collected.Main Outcome Measures: The coprimary outcomes were composite AMI and CHF indicators based on 12 AMI and 6 CHF process-of-care indicators. Secondary outcomes were the individual process-of-care indicators, a hospital report card impact survey, and all-cause AMI and CHF mortality.Results: The publication of the early feedback hospital report card did not result in a significant systemwide improvement in the early feedback group in either the composite AMI process-of-care indicator (absolute change, 1.5%; 95% confidence interval [CI], -2.2% to 5.1%; P = .43) or the composite CHF process-of-care indicator (absolute change, 0.6%; 95% CI, -4.5% to 5.7%; P = .81). During the follow-up period, the mean 30-day AMI mortality rates were 2.5% lower (95% CI, 0.1% to 4.9%; P = .045) in the early feedback group compared with the delayed feedback group. The hospital mortality rates for CHF were not significantly different.Conclusion: Public release of hospital-specific quality indicators did not significantly improve composite process-of-care indicators for AMI or CHF.Trial Registration: http://clinicaltrials.gov Identifier: NCT00187460. [ABSTRACT FROM AUTHOR]- Published
- 2009
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4. Analysis of observational studies in the presence of treatment selection bias: effects of invasive cardiac management on AMI survival using propensity score and instrumental variable methods.
- Author
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Stukel TA, Fisher ES, Wennberg DE, Alter DA, Gottlieb DJ, Vermeulen MJ, Stukel, Thérèse A, Fisher, Elliott S, Wennberg, David E, Alter, David A, Gottlieb, Daniel J, and Vermeulen, Marian J
- Abstract
Context: Comparisons of outcomes between patients treated and untreated in observational studies may be biased due to differences in patient prognosis between groups, often because of unobserved treatment selection biases.Objective: To compare 4 analytic methods for removing the effects of selection bias in observational studies: multivariable model risk adjustment, propensity score risk adjustment, propensity-based matching, and instrumental variable analysis.Design, Setting, and Patients: A national cohort of 122,124 patients who were elderly (aged 65-84 years), receiving Medicare, and hospitalized with acute myocardial infarction (AMI) in 1994-1995, and who were eligible for cardiac catheterization. Baseline chart reviews were taken from the Cooperative Cardiovascular Project and linked to Medicare health administrative data to provide a rich set of prognostic variables. Patients were followed up for 7 years through December 31, 2001, to assess the association between long-term survival and cardiac catheterization within 30 days of hospital admission.Main Outcome Measure: Risk-adjusted relative mortality rate using each of the analytic methods.Results: Patients who received cardiac catheterization (n = 73 238) were younger and had lower AMI severity than those who did not. After adjustment for prognostic factors by using standard statistical risk-adjustment methods, cardiac catheterization was associated with a 50% relative decrease in mortality (for multivariable model risk adjustment: adjusted relative risk [RR], 0.51; 95% confidence interval [CI], 0.50-0.52; for propensity score risk adjustment: adjusted RR, 0.54; 95% CI, 0.53-0.55; and for propensity-based matching: adjusted RR, 0.54; 95% CI, 0.52-0.56). Using regional catheterization rate as an instrument, instrumental variable analysis showed a 16% relative decrease in mortality (adjusted RR, 0.84; 95% CI, 0.79-0.90). The survival benefits of routine invasive care from randomized clinical trials are between 8% and 21%.Conclusions: Estimates of the observational association of cardiac catheterization with long-term AMI mortality are highly sensitive to analytic method. All standard risk-adjustment methods have the same limitations regarding removal of unmeasured treatment selection biases. Compared with standard modeling, instrumental variable analysis may produce less biased estimates of treatment effects, but is more suited to answering policy questions than specific clinical questions. [ABSTRACT FROM AUTHOR]- Published
- 2007
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5. Lipid-lowering therapy with statins in high-risk elderly patients: the treatment-risk paradox.
- Author
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Ko DT, Mamdani M, Alter DA, Ko, Dennis T, Mamdani, Muhammad, and Alter, David A
- Abstract
Context: The benefits of cardiovascular therapies such as statins for secondary prevention have been well documented, although they may not be optimally used in patients most likely to benefit. Ideally, aggressiveness in the use of these beneficial therapies should correlate with baseline cardiovascular risk.Objective: To examine the association between physicians' treatment aggressiveness and baseline cardiovascular risk.Design, Setting, and Patients: Retrospective cohort study incorporating the use of multiple linked health care administrative databases covering more than 1.4 million elderly residents of Ontario. We included 396,077 patients aged 66 years or older who had a history of cardiovascular disease or diabetes while undergoing medical treatment and who were alive on April 1, 1998. Baseline cardiovascular risk was derived using a risk-adjustment index in which we modeled probability of death after 3 years of follow-up.Main Outcome Measure: Likelihood of statin use, stratified by baseline cardiovascular risk, after adjusting for age, sex, socioeconomic status, and rural or urban residence.Results: Only 75,617 patients (19.1%) in this secondary prevention cohort were prescribed statins. In patients 66 to 74 years old, the adjusted probabilities of statin prescription were 37.7%, 26.7%, and 23.4% in the categories of low, intermediate, and high baseline risk, respectively. The likelihood of statin prescription was 6.4% lower (adjusted odds ratio, 0.94; 95% confidence interval, 0.93-0.95) for each year of increase in age and each 1% increase in predicted 3-year mortality risk. The influence of age also interacted synergistically with baseline risk on the prescription of statins (P<.001).Conclusions: We found that prescription of statins diminished progressively as baseline cardiovascular risk and future probability of death increased. Since the benefits of a therapy are dependent on the baseline risk, the maximum benefits of statins may not be fully realized until implementation of therapy includes patients at highest risk. [ABSTRACT FROM AUTHOR]- Published
- 2004
6. Mortality and adherence to pharmacotherapy after acute myocardial infarction.
- Author
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Kinjo M, Kinjo K, Iwata I, Setoguchi S, Parakh K, Bush D, Ziegelstein RC, Thombs BD, Fauerbach JA, Rasmussen JN, Alter DA, Parakh, Kapil, Bush, David E, Ziegelstein, Roy C, Thombs, Brett D, and Fauerbach, James A
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- 2007
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7. Association of hospital spending intensity with mortality and readmission rates in Ontario hospitals.
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Stukel TA, Fisher ES, Alter DA, Guttmann A, Ko DT, Fung K, Wodchis WP, Baxter NN, Earle CC, and Lee DS
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- Adolescent, Adult, Aged, Aged, 80 and over, Colonic Neoplasms therapy, Female, Health Expenditures statistics & numerical data, Heart Failure therapy, Hip Fractures therapy, Humans, Longitudinal Studies, Male, Middle Aged, Myocardial Infarction therapy, Ontario epidemiology, Quality of Health Care, Treatment Outcome, Young Adult, Colonic Neoplasms mortality, Economics, Hospital, Heart Failure mortality, Hip Fractures mortality, Hospital Costs statistics & numerical data, Myocardial Infarction mortality, Patient Readmission statistics & numerical data
- Abstract
Context: The extent to which better spending produces higher-quality care and better patient outcomes in a universal health care system with selective access to medical technology is unknown., Objective: To assess whether acute care patients admitted to higher-spending hospitals have lower mortality and readmissions., Design, Setting, and Patients: The study population comprised adults (>18 years) in Ontario, Canada, with a first admission for acute myocardial infarction (AMI) (n = 179,139), congestive heart failure (CHF) (n = 92,377), hip fracture (n = 90,046), or colon cancer (n = 26,195) during 1998-2008, with follow-up to 1 year. The exposure measure was the index hospital's end-of-life expenditure index for hospital, physician, and emergency department services., Main Outcome Measures: The primary outcomes were 30-day and 1-year mortality and readmissions and major cardiac events (readmissions for AMI, angina, CHF, or death) for AMI and CHF., Results: Patients' baseline health status was similar across hospital expenditure groups. Patients admitted to hospitals in the highest- vs lowest-spending intensity terciles had lower rates of all adverse outcomes. In the highest- vs lowest-spending hospitals, respectively, the age- and sex-adjusted 30-day mortality rate was 12.7% vs 12.8% for AMI, 10.2% vs 12.4% for CHF, 7.7% vs 9.7% for hip fracture, and 3.3% vs 3.9% for CHF; fully adjusted relative 30-day mortality rates were 0.93 (95% CI, 0.89-0.98) for AMI, 0.81 (95% CI, 0.76-0.86) for CHF, 0.74 (95% CI, 0.68-0.80) for hip fracture, and 0.78 (95% CI, 0.66-0.91) for colon cancer. Results for 1-year mortality, readmissions, and major cardiac events were similar. Higher-spending hospitals had higher nursing staff ratios, and their patients received more inpatient medical specialist visits, interventional (AMI cohort) and medical (AMI and CHF cohorts) cardiac therapies, preoperative specialty care (colon cancer cohort), and postdischarge collaborative care with a cardiologist and primary care physician (AMI and CHF cohorts)., Conclusion: Among Ontario hospitals, higher spending intensity was associated with lower mortality, readmissions, and cardiac event rates.
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- 2012
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8. Thiazolidinediones and cardiovascular outcomes in older patients with diabetes.
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Lipscombe LL, Gomes T, Lévesque LE, Hux JE, Juurlink DN, and Alter DA
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- Aged, Aged, 80 and over, Cause of Death, Female, Humans, Male, Pioglitazone, Retrospective Studies, Risk, Rosiglitazone, Diabetes Mellitus drug therapy, Heart Failure epidemiology, Hypoglycemic Agents therapeutic use, Myocardial Infarction epidemiology, Thiazolidinediones therapeutic use
- Abstract
Context: Thiazolidinediones (TZDs), used to treat type 2 diabetes, are associated with an excess risk of congestive heart failure and possibly acute myocardial infarction. However, the association between TZD use and cardiovascular events has not been adequately evaluated on a population level., Objective: To explore the association between TZD therapy and congestive heart failure, acute myocardial infarction, and mortality compared with treatment with other oral hypoglycemic agents., Design, Setting, and Patients: Nested case-control analysis of a retrospective cohort study using health care databases in Ontario. We included diabetes patients aged 66 years or older treated with at least 1 oral hypoglycemic agent between 2002 and 2005 (N = 159 026) and followed them up until March 31, 2006., Main Outcome Measures: The primary outcome consisted of an emergency department visit or hospitalization for congestive heart failure; secondary outcomes were an emergency department visit or hospitalization for acute myocardial infarction and all-cause mortality. The risks of these events were compared between persons treated with TZDs (rosiglitazone and pioglitazone) and other oral hypoglycemic agent combinations, after matching and adjusting for prognostic factors., Results: During a median follow-up of 3.8 years, 12 491 patients (7.9%) had a hospital visit for congestive heart failure, 12,578 (7.9%) had a visit for acute myocardial infarction, and 30 265 (19%) died. Current treatment with TZD monotherapy was associated with a significantly increased risk of congestive heart failure (78 cases; adjusted rate ratio [RR], 1.60; 95% confidence interval [CI], 1.21-2.10; P < .001), acute myocardial infarction (65 cases; RR, 1.40; 95% CI, 1.05-1.86; P = .02), and death (102 cases; RR, 1.29; 95% CI, 1.02-1.62; P = .03) compared with other oral hypoglycemic agent combination therapies (3478 congestive heart failure cases, 3695 acute myocardial infarction cases, and 5529 deaths). The increased risk of congestive heart failure, acute myocardial infarction, and mortality associated with TZD use appeared limited to rosiglitazone., Conclusion: In this population-based study of older patients with diabetes, TZD treatment, primarily with rosiglitazone, was associated with an increased risk of congestive heart failure, acute myocardial infarction, and mortality when compared with other combination oral hypoglycemic agent treatments.
- Published
- 2007
- Full Text
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9. Relationship between adherence to evidence-based pharmacotherapy and long-term mortality after acute myocardial infarction.
- Author
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Rasmussen JN, Chong A, and Alter DA
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- Adrenergic beta-Antagonists therapeutic use, Aged, Calcium Channel Blockers therapeutic use, Female, Humans, Hydroxymethylglutaryl-CoA Reductase Inhibitors therapeutic use, Longitudinal Studies, Male, Survival Analysis, Myocardial Infarction drug therapy, Patient Compliance, Survivors
- Abstract
Context: The extent to which drug adherence may affect survival remains unclear, in part because mortality differences may be attributable to "healthy adherer" behavioral attributes more so than to pharmacological benefits., Objective: To explore the relationship between drug adherence and mortality in survivors of acute myocardial infarction (AMI)., Design, Setting, and Participants: Population-based, observational, longitudinal study of 31 455 elderly AMI survivors between 1999 and 2003 in Ontario. All patients filled a prescription for statins, beta-blockers, or calcium channel blockers, with the latter drug considered a control given the absence of clinical trial-proven survival benefits., Main Outcome Measures: Patient adherence was subdivided a priori into 3 categories--high (proportion of days covered, > or =80%), intermediate (proportion of days covered, 40%-79%), and low (proportion of days covered, <40%)--and compared with long-term mortality (median of 2.4 years of follow-up) using multivariable survival models (and propensity analyses) adjusted for sociodemographic factors, illness severity, comorbidities, and concomitant use of evidence-based therapies., Results: Among statin users, compared with their high-adherence counterparts, the risk of mortality was greatest for low adherers (deaths in 261/1071 (24%) vs 2310/14,345 (16%); adjusted hazard ratio, 1.25; 95% confidence interval, 1.09-1.42; P = .001) and was intermediary for intermediate adherers (deaths in 472/2407 (20%); adjusted hazard ratio, 1.12; 95% confidence interval, 1.01-1.25; P = .03). A similar but less pronounced dose-response-type adherence-mortality association was observed for beta-blockers. Mortality was not associated with adherence to calcium channel blockers. Moreover, sensitivity analyses demonstrated no relationships between drug adherence and cancer-related admissions, outcomes for which biological plausibility do not exist., Conclusion: The long-term survival advantages associated with improved drug adherence after AMI appear to be class-specific, suggesting that adherence outcome benefits are mediated by drug effects and do not merely reflect an epiphenomenon of "healthy adherer" behavioral attributes.
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- 2007
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10. Risk-treatment mismatch in the pharmacotherapy of heart failure.
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Lee DS, Tu JV, Juurlink DN, Alter DA, Ko DT, Austin PC, Chong A, Stukel TA, Levy D, and Laupacis A
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- Aged, Drug Utilization, Female, Heart Failure mortality, Humans, Male, Middle Aged, Ontario, Risk, Survival Analysis, Adrenergic beta-Antagonists therapeutic use, Angiotensin II antagonists & inhibitors, Angiotensin Receptor Antagonists, Angiotensin-Converting Enzyme Inhibitors therapeutic use, Cardiovascular Agents therapeutic use, Heart Failure drug therapy
- Abstract
Context: Patients with heart failure have a wide spectrum of mortality risks. To maximize the benefit of available pharmacotherapies, patients with high mortality risk should receive high rates of drug therapy., Objective: To examine patterns of drug therapy and underlying mortality risk in patients with heart failure., Design, Setting, and Patients: In the Enhanced Feedback for Effective Cardiac Treatment (EFFECT) population-based cohort (1999-2001) of 9942 patients with heart failure hospitalized in Ontario, Canada, we evaluated 1418 patients with documented left ventricular ejection fraction of 40% or less and aged 79 years or younger with low-, average-, and high-predicted risk of death within 1 year; all patients survived to hospital discharge. Administration of angiotensin-converting enzyme (ACE) inhibitors, ACE inhibitors or angiotensin II receptor blockers (ARBs), and beta-adrenoreceptor antagonists was evaluated according to predicted risk of death., Main Outcome Measure: Heart failure drug administration rates at time of discharge and 90 days after hospital discharge., Results: At hospital discharge, prescription rates for patients in the low-, average-, and high-risk groups were 81%, 73%, 60%, respectively, for ACE inhibitors; 86%, 80%, 65%, respectively, for ACE inhibitors or ARBs; and 40%, 33%, 24%, respectively, for beta-adrenoreceptor antagonists (all P<.001 for trend). Within 90 days following hospital discharge, the rates were 83%, 76%, and 61% for ACE inhibitors; 89%, 83%, and 67% for ACE inhibitors or ARBs; and 43%, 36%, and 28% for beta-adrenoreceptor antagonists for the 3 risk groups, respectively (all P<.001 for trend). The pattern of lower rates of drug administration in those patients at increasing risk was maintained up to 1 year postdischarge (P<.001). After accounting for varying survival time and potential contraindications to therapy, low-risk patients were more likely to receive ACE inhibitors or ARBs (adjusted hazard ratio [HR], 1.61; 95% confidence interval [CI], 1.49-1.74) and beta-adrenoreceptor antagonists (HR, 1.80; 95% CI, 1.60-2.01) compared with high-risk patients (both P<.001)., Conclusions: Patients with heart failure at greatest risk of death are least likely to receive ACE inhibitors, ACE inhibitors or ARBs, and beta-adrenoreceptor antagonists. Understanding the reasons underlying this mismatch may facilitate improvements in care and outcomes for patients with heart failure.
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- 2005
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11. Socioeconomic status, service patterns, and perceptions of care among survivors of acute myocardial infarction in Canada.
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Alter DA, Iron K, Austin PC, and Naylor CD
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- Adult, Aged, Canada, Cardiology economics, Cardiology statistics & numerical data, Cohort Studies, Coronary Angiography statistics & numerical data, Educational Status, Female, Humans, Male, Middle Aged, Myocardial Infarction economics, Myocardial Infarction ethnology, National Health Programs, Private Sector, Survivors, Treatment Outcome, Attitude to Health, Health Services Accessibility economics, Myocardial Infarction therapy, Social Class
- Abstract
Context: Some have argued that Canada's uniquely restrictive approach to private health insurance keeps the socioeconomic elite inside the public system so that their demands and influence elevate the standard of service for all Canadian citizens. The extent to which this theory is a valid representation of Canadian health care is unknown., Objectives: To explore how patients with acute myocardial infarction from different socioeconomic backgrounds perceive their care in Canada's universal health care system and to correlate patients' backgrounds and perceptions with actual care received., Design, Setting, and Patients: Prospective observational cohort study with follow-up telephone interviews of 2256 patients 30 days following acute myocardial infarction discharged from 53 hospitals across Ontario, Canada, between December 1999 and June 2002., Main Outcome Measures: Postdischarge use of cardiac specialty services; satisfaction with care; willingness to pay directly for faster service or more choice; and mortality according to income and education, adjusted for age, sex, ethnicity, clinical factors, onsite angiography capacity at the admitting hospital, and rural-urban residence., Results: Compared with patients in lower socioeconomic strata, more affluent or better educated patients were more likely to undergo coronary angiography (67.8% vs 52.8%; P<.001), receive cardiac rehabilitation (43.9% vs 25.6%; P<.001), or be followed up by a cardiologist (56.7% vs 47.8%; P<.001). Socioeconomic differences in cardiac care persisted after adjustment for confounders. Despite receiving more specialized services, patients with higher socioeconomic status were more likely to be dissatisfied with their access to specialty care (adjusted RR, 2.02; 95% confidence interval, 1.20-3.32) and to favor out-of-pocket payments for quicker access to a wider selection of treatment options (30% vs 15% for patients with household incomes of Can 60 000 dollars or higher vs less than Can 30 000 dollars, respectively; P<.001). After adjusting for baseline characteristics, socioeconomic status was not significantly associated with mortality at 1 year following hospitalization for myocardial infarction., Conclusions: Compared with those with lower incomes or less education, upper middle-class Canadians gain preferential access to services within the publicly funded health care system yet remain more likely to favor supplemental coverage or direct purchase of services.
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- 2004
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12. Long-term MI outcomes at hospitals with or without on-site revascularization.
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Alter DA, Naylor CD, Austin PC, and Tu JV
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- Aged, Female, Hospital Mortality, Humans, Male, Middle Aged, Myocardial Infarction mortality, Ontario epidemiology, Recurrence, Retrospective Studies, Socioeconomic Factors, Emergency Service, Hospital statistics & numerical data, Hospitals statistics & numerical data, Myocardial Infarction therapy, Myocardial Revascularization statistics & numerical data, Outcome and Process Assessment, Health Care
- Abstract
Context: Many studies have found that patients with acute myocardial infarction (AMI) who are admitted to hospitals with on-site revascularization facilities have higher rates of invasive cardiac procedures and better outcomes than patients in hospitals without such facilities. Whether such differences are due to invasive procedure rates alone or to other patient, physician, and hospital characteristics is unknown., Objective: To determine whether invasive procedural rate variations alone account for outcome differences in patients with AMI admitted to hospitals with or without on-site revascularization facilities., Design: Retrospective, observational cohort study using linked population-based administrative data from a universal health insurance system., Setting: One hundred ninety acute care hospitals in Ontario, 9 of which offered invasive procedures., Patients: A total of 25 697 patients hospitalized with AMI between April 1, 1992, and December 31, 1993, of whom 2832 (11%) were in invasive hospitals., Main Outcome Measures: Mortality, recurrent cardiac hospitalizations, and emergency department visits in the 5 years following the index admission, adjusted for patient age, sex, socioeconomic status, illness severity, and index revascularization procedures; attending physician specialty; and hospital volume, teaching status, and geographical proximity to invasive-procedure centers and compared by hospital type., Results: Patients admitted to invasive-procedure hospitals were much more likely to undergo revascularization (11.4% vs 3.2% at other hospitals; P<.001). However, many other clinical and process-related factors differed between the 2 groups. Although mortality rates were similar between the 2 institution types, the nonfatal composite 5-year event rate (ie, recurrent cardiac hospitalization and emergency department visits) was lower for patients initially admitted to invasive-procedure hospitals (71.3% vs 80.4%; unadjusted odds ratio [OR], 0.65; 95% confidence interval [CI], 0.52-0.82; P<.001). This advantage persisted after adjustment for sociodemographic and clinical factors and procedure utilization (adjusted OR, 0.68; 95% CI, 0.53-0.89; P<.001). However, the nonfatal outcome advantages of invasive-procedure hospitals were explained by their teaching status (adjusted OR, 0.98; 95% CI, 0.73-1.30; P =.87)., Conclusions: In this sample of patients admitted with AMI, the differing outcomes of apparently similar patients treated in 2 different practice settings were explained by multiple competing factors. Researchers conducting observational studies should be cautious about attributing patient outcome differences to any single factor.
- Published
- 2001
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