Association Between Preadmission Functional Status and Use and Effectiveness of Secondary Prevention Medications in Elderly Survivors of Acute Myocardial Infarction.

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.