Abstract
OBJECTIVES: To determine whether function-related indicators (FRIs), derived from preadmission claims data, help explain the frequent practice of forgoing secondary prevention medications observed in Medicare. DESIGN: Retrospective cohort. SETTING: National Medicare data. PARTICIPANTS: Elderly Medicare beneficiaries discharged alive from an acute myocardial infarction (AMI) hospitalization in 2007-2008 (N = 184,156). MEASUREMENTS: Study outcomes were number of guideline-recommended secondary prevention medications (statins, beta-blockers, and angiotensin-converting enzyme inhibitors or angiotensin receptor blockers) used after discharge and 12-month survival. Preadmission data (FRIs, cardiovascular conditions, comorbid conditions), type of AMI (non-ST-elevation myocardial infarction, anterior, other), and procedures and complications during the hospitalization were from claims data. RESULTS: Function-related indicators (FRIs) were common before admission; 50% of individuals had at least one (range 0-11). After discharge, 85.8% used at least one class of guideline medication, and 30.2% used all three; 19.6% died within 12 months. Each additional FRI reduced the likelihood of receiving all three medication classes by 5% (adjusted odds ratio = 0.95, 95% confidence interval (CI) = 0.94-0.96) and increased 12-month mortality by 20% (adjusted hazard ratio (aHR) = 1.20, 95% CI = 1.19-1.21). Individuals taking all three classes of medication were 30% less likely to die within 12 months than those not taking guideline medications (aHR = 0.70, 95% CI = 0.67-0.73). Similar survival benefit was observed in individuals with and without functional impairments. CONCLUSION: Greater impairment in preadmission functional status, using a measure derived from claims data, was associated with less use of secondary prevention medications after AMI. Survival benefits of taking these medications were consistent across functional impairment levels.