Generic and therapeutic statin switches and disruptions in therapy

ABSTRACTBackground: The study objective was to compare dose-equivalence, adherence and subsequent switch rates among patients recently switched from a branded to generic version of the same statin (generic substitution, GS) vs. those switched from branded statin to generic version of a different statin (therapeutic substitution, TS).Methods: In a retrospective cohort analysis among adult enrollees in over 90 US health plans, the authors identified adult patients who switched from a branded to generic statin from July–December 2006 (simvastatin became generic in June 2006). Patients were classified by type of statin switch: GS (e.g., branded simvastatin → generic simvastatin), and TS (e.g., branded atorvastatin → generic simvastatin). Demographic and clinical data were collected from claims before switch through 6 months follow-up. Separate outcomes of interest included proportion of patients that switched to a less potent daily dose, that switched back to previous branded statin after switch, and that wer...