Background: Statins reduce mortality after acute myocardial infarction, but up to half of patients discontinue statin use within 1 year of therapy initiation. Although cost may influence medication adherence, it is unknown whether use of generic versus brand statins influences adherence.
Methods and results: We linked detailed inhospital clinical data for 1421 non-ST-segment elevation myocardial infarction patients discharged on a statin in 2006 to Medicare Part D medication claims records to examine postdischarge medication use. One-year statin adherence was defined using the proportion of days covered with optimal adherence ≥80%. We examined the association of brand versus generic statin prescription and 1-year adherence after adjusting for demographics, clinical factors, predischarge lipid values, prior statin use, and socioeconomic status. Overall, 65.5% of statin fills were for brand-name statins. There were few baseline differences in demographics and clinical factors among generic versus brand users. Patient copay amounts were higher for brand versus generic statins (median = $25 vs $5, P < .001), yet the mean proportion of days covered over 1 year was similar (71.5% vs 68.9%; P = .97; unadjusted odds ratio 1.15 [95% CI 0.96-1.37]). Proportion of days covered ≥80% was low for both generic (56.2%) and brand statins (55.9%; P = .93). Statin adherence rates remained similar between generic and brand users after adjusting for demographics, clinical risk factors, lipid value, prior statin use, and socioeconomic status.
Conclusions: In a cohort of older non-ST-segment elevation myocardial infarction patients, we found no evidence that use of generic versus brand drug was associated with higher adherence to statins at 1 year after hospital discharge.
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