Abstract
BACKGROUND: Medicare patients with coronary artery disease (CAD) have been a significant focus of value-based payment programs for outpatient practices. Physicians and policymakers, however, have voiced concern that value-based payment programs may penalize practices that serve vulnerable populations. This study evaluated whether outpatient practices that serve socioeconomically disadvantaged populations have worse CAD outcomes, and if this reflects the delivery of lower-quality care or rather, patient and community factors beyond the care provided by physician practices. METHODS AND RESULTS: Retrospective cohort study of Medicare fee-for-service patients ≥65 years with CAD at outpatient practices participating in the the Practice Innovation and Clinical Excellence registry from January 1, 2010 to January 1, 2015. Outpatient practices were stratified into quintiles by the proportion of most disadvantaged patients-defined by an area deprivation score in the highest 20% nationally-served at each practice site. Prescription of guideline recommended therapies for CAD as well as clinical outcomes (emergency department presentation for chest pain, hospital admission for unstable angina or acute myocardial infarction [AMI], 30-day readmission after AMI, and 30-day mortality after AMI) were evaluated by practice-level socioeconomic disadvantage with hierarchical logistic regression models, using practices serving the fewest socioeconomically disadvantaged patients as a reference. The study included 453 783 Medicare fee-for-service patients ≥65 years of age with CAD (mean [SD] age, 75.3 [7.7] years; 39.7% female) cared for at 271 outpatient practices. At practices serving the highest proportion of socioeconomically disadvantaged patients (group 5), compared with practices serving the lowest proportion (group 1), there was no significant difference in the likelihood of prescription of antiplatelet therapy (odds ratio [OR], 0.94 [95% CI, 0.69-1.27]), β-blocker therapy if prior myocardial infarction or left ventricular ejection fraction <40% (OR, 0.97 [95% CI, 0.69-1.35]), ACE (angiotensin-converting enzyme) inhibitor or angiotensin receptor blocker if left ventricular ejection fraction <40% and/or diabetes mellitus (OR, 0.93 [95% CI, 0.74-1.19]), statin therapy (OR, 0.88 [95% CI, 0.68-1.14]), or cardiac rehabilitation (OR, 0.45 [95% CI, 0.20-1.00]). Patients cared for at the most disadvantaged-serving practices (group 5) were more likely to be admitted for unstable angina (adjusted OR, 1.46 [95% CI, 1.04-2.05]). There was no significant difference in the likelihood of emergency department presentation for chest pain or hospital admission for AMI between practices. Thirty day mortality rates after AMI were higher among patients at the most disadvantaged-serving practices (aOR, 1.31 [95% CI, 1.02-1.68]), but 30-day readmission rates did not differ. All associations were attenuated after additional adjustment for patient-level area deprivation index. CONCLUSIONS: Physician outpatient practices that serve the most socioeconomically disadvantaged patients with CAD perform worse on some clinical outcomes, despite providing similar guideline-recommended care as other practices, and consequently could fare poorly under value-based payment programs. Social factors beyond care provided by outpatient practices may partly explain worse outcomes. Policymakers should consider accounting for socioeconomic disadvantage in value-based payment programs initiatives that target outpatient practices.