Association of patient case-mix adjustment, hospital process performance rankings, and eligibility for financial incentives.

CONTEXT While most comparisons of hospital outcomes adjust for patient characteristics, process performance comparisons typically do not. OBJECTIVE To evaluate the degree to which hospital process performance ratings and eligibility for financial incentives are altered after accounting for hospitals' patient demographics, clinical characteristics, and mix of treatment opportunities. DESIGN, SETTING, AND PATIENTS Using data from the American Heart Association's Get With the Guidelines program between January 2, 2000, and March 28, 2008, we analyzed hospital process performance based on the Centers for Medicare & Medicaid Services' defined core measures for acute myocardial infarction. Hospitals were initially ranked based on crude composite process performance and then ranked again after accounting for hospitals' patient demographics, clinical characteristics, and eligibility for measures using a hierarchical model. We then compared differences in hospital performance rankings and pay-for-performance financial incentive categories (top 20%, middle 60%, and bottom 20% institutions). MAIN OUTCOME MEASURES Hospital process performance ranking and pay-for-performance financial incentive categories. RESULTS A total of 148,472 acute myocardial infarction patients met the study criteria from 449 centers. Hospitals for which crude composite acute myocardial infarction performance was in the bottom quintile (n = 89) were smaller nonacademic institutions that treated a higher percentage of patients from racial or ethnic minority groups and also patients with greater comorbidities than hospitals ranked in the top quintile (n = 90). Although there was overall agreement on hospital rankings based on observed vs adjusted composite scores (weighted kappa, 0.74), individual hospital ranking changed with adjustment (median, 22 ranks; range, 0-214; interquartile range, 9-40). Additionally, 16.5% of institutions (n = 74) changed pay-for-performance financial status categories after accounting for patient and treatment opportunity mix. CONCLUSION Our findings suggest that accounting for hospital differences in patient characteristics and treatment opportunities is associated with modest changes in hospital performance rankings and eligibility for financial benefits in pay-for-performance programs for treatment of myocardial infarction.