Impact of fixed-dose and multi-pill combination dyslipidemia therapies on medication adherence and the economic burden of sub-optimal adherence

Abstract Objective: To compare medication adherence between patients initiating fixed-dose combination versus multi-pill combination dyslipidemia therapies and assess the association between optimal adherence (MPR ≥ 80%) and cardiovascular disease (CVD)-associated total healthcare resource utilization (THR) and costs (THC). Research design and methods: The HealthCore Integrated Research Database was used to identify patients ≥18 years newly initiating fixed-dose combination [niacin extended-release (NER) and lovastatin (NERL)] or multi-pill combination therapies [NER and simvastatin (NER/S) or lovastatin (NER/L)] between 1/1/2000 and 6/30/2006 (index date), with minimum 18 months of follow-up. Adherence was measured using medication possession ratio (MPR). Three multivariate models were developed controlling for demographic and clinical characteristics. A logistic model evaluated the association between study cohorts and optimal adherence, while negative binomial and gamma models estimated the association between optimal adherence and CVD-associated THR and THC, respectively. Results: In all, 6638 NERL, 1687 NER/S, and 663 NER/L patients were identified. Fixed-dose combination patients were younger [mean (SD) ages of 51.9 (10.5) vs. 56.0 (9.4) [NER/S] and 56.1 (10.6) [NER/L]; p