Adherence to single-pill combination versus multiple-pill combination lipid-modifying therapy among patients with mixed dyslipidemia in a managed care population.

BACKGROUND: Suboptimal adherence to lipid-lowering therapies is associated with and potentially contributes to increased cardiovascular morbidity and mortality. Single-pill combination (SPC) lipid-modifying therapies may improve patient adherence due to decreased pill burden and increased convenience for the patient. OBJECTIVE: To compare adherence to SPC versus multi-pill combination (MPC) lipid-modifying medications. METHODS: This retrospective study used pharmacy and medical claims and laboratory result data from a national managed care dataset to evaluate patients who were newly prescribed simvastatin plus ezetimibe, simvastatin plus niacin, and lovastatin plus niacin either as SPC or MPC. Patients were considered adherent to therapy if they had a proportion of days covered (PDC) ≥ 0.80. RESULTS: The mean PDC was 0.76 and 0.70 in the first 3 months of therapy, 0.54 and 0.45 in the second 3 months, and 0.50 and 0.41 for the remaining 30 months of follow-up for the SPC and MPC groups, respectively. SPC patients were 32% (OR = 1.32; 95% CI: 1.27-1.36; P < 0.01) more likely to be adherent to treatment than MPC patients. CONCLUSION: Adherence was significantly higher among patients receiving SPC than MPC. Although only associations and not temporality were assessed due to the observational design of this study, the use of SPC may be a successful method for improving adherence in a real-world setting.