Geographic variation in statin use for complex acute myocardial infarction patients: evidence of effective care?

BACKGROUND Despite strong evidence to designate statin use for secondary prevention of cardiovascular disease (CVD) as "effective care," observational studies show that many patients with CVD do not receive statins. This suggests that statin prescribing decisions for complex CVD patients are preference sensitive. OBJECTIVES The aim of this study was to evaluate local area variation in statin prescribing for subsets of complex patients after acute myocardial infarction (AMI) to assess whether current statin prescribing patterns fit profiles of either "effective care" or "preference-sensitive care." RESEARCH DESIGN AND SUBJECTS This was a retrospective cohort study of 124,618 Medicare patients with fee-for-service parts A, B, and D benefits who were hospitalized with AMI in 2008 or 2009 with no evidence of AMI in the past 12 months. MEASURES Patient complexity was defined by the presence of diabetes, heart failure, and chronic kidney disease in the year before AMI admission. Local area practice styles for "no statin," "lower-intensity statins," and "high-intensity statins" were measured using the driving area for clinical care method. Statin prescribing rates for complex patient subsets were contrasted across patients grouped by local areas practice styles. RESULTS Lower statin treatment rates were observed for patients with complex conditions, especially among those with heart failure. However, substantial local area variation in statin prescribing is observed across all complex patient groups. CONCLUSIONS Despite guidelines promoting the use of statins for secondary prevention for CVD patients, substantial local area variation suggests that patient and provider beliefs and preferences weigh heavily in statin prescribing decisions.