Adherence, Persistence, and Predictors Associated with Early Niacin Termination

Abstract

Background: Niacin is the most effective therapy currently available to increase high-density lipoprotein cholesterol. However, adherence to niacin may be limited by a number of factors and it is important to characterize who is likely to discontinue the medicine. Objective: To measure adherence and persistence to niacin, estimate the influence of niacin dose on adherence, and identify factors associated with early termination of niacin. Methods: This retrospective study estimated adherence to niacin by calculating the medication possession ratio, persistence, number of refills, and termination proportion in a large, deidentified US health claims database consisting of 42,685 insurance-carrying adults who were new users of niacin. Results: We identified 29,801 new users of niacin who were not taking statins or fibric acid, 12,298 new users of niacin plus statin, 441 new users of niacin plus fibric acid, and 145 new users who initiated all 3 agents. Persistence was lowest among individuals taking less than 1 g/day and was highest among those taking niacin plus fibric acid plus statin (5.10 vs 7.17 months, respectively). However, lower niacin dose was associated with greater adherence, regardless of statin use. Termination of niacin within 1 year of initiation was significantly associated with being female or having 1 of the following conditions: peripheral vascular disease, chronic pulmonary disease, diabetes mellitus, rheumatic disease, or liver disease. Increased age, taking niacin in combination with a statin, or taking drugs from 2 or more concomitant prescription medication classes were significantly associated with a reduced likelihood of termination within 1 year. Conclusions: We observed relatively high adherence rates to niacin; however, most patients failed to persist with use of the drug beyond 7 months.