Does Higher Spending Improve Survival Outcomes for Myocardial Infarction? Examining the Cost‐Outcomes Relationship Using Time‐Varying Covariates. (9th February 2015)

• Record Type: Journal Article
• Authors: Cohen, Deborah; Manuel, Douglas G.; Tugwell, Peter; Sanmartin, Claudia; Ramsay, Tim
• Is Part Of: Health services research. Volume 50:Number 5(2015)
• Page Start: 1589
• Page End: 1605
• Publication Date: 2015-02-09
• Subjects: Medical care -- Periodicals; Medical care -- Evaluation -- Periodicals; Hospital care -- Periodicals; Health services administration -- Periodicals; 362
• DOI: 10.1111/1475-6773.12286
• Languages: English
• ISSNs: 0017-9124

Abstract

<abstract abstract-type="main" id="hesr12286-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="hesr12286-sec-0001" sec-type="section"> <title>Objectives</title> <p>Previous patient‐level acute myocardial infarction (AMI) research has found higher hospital spending to be associated with improved survival; however, survivor‐treatment selection bias traditionally has been overlooked. The purpose of this study was to examine the AMI cost‐outcome relationship, taking into account this form of bias.</p> </sec> <sec id="hesr12286-sec-0002" sec-type="section"> <title>Data Sources</title> <p>Hospital Discharge Abstract data tracked costs for AMI hospitalizations. Ontario Vital Statistics data tracked patient mortality.</p> </sec> <sec id="hesr12286-sec-0003" sec-type="section"> <title>Study Design</title> <p>A standard Cox survival model was compared to an extended Cox model using hospital costs as a time‐varying covariate to examine the impact of cost on 1‐year survival in a cohort of 30, 939 first‐time AMI patients in Ontario, Canada, from 2007 to 2010.</p> </sec> <sec id="hesr12286-sec-0004" sec-type="section"> <title>Principal Findings</title> <p>Higher patient‐level AMI spending decreased the hazard of dying (Standard Model: log‐cost hazard ratio: 0.513, 95 percent CI: 0.479–0.549; Extended Model: log‐cost hazard ratio: 0.700, 95 percent CI: 0.645–0.758); however, the protective effect was overestimated by 62 percent when survivor‐treatment bias was overlooked. In the extended model, a 10 percent increase in spending was associated with a 3.6 percent decrease in hazard of death.</p> </sec> <sec id="hesr12286-sec-0005" sec-type="section"> <title>Conclusion</title> <p>The findings of this study suggest that if survivor‐treatment bias is overlooked, future research may materially overstate the protective effect of patient‐level spending on outcomes.</p> </sec> </abstract>