Long-term persistence with statin treatment in a not-for-profit health maintenance organization: A population-based retrospective cohort study in Israel

Background: Although discontinuing lipid-lowering treatment can cause preventable morbidity, previously published reports have indicated considerable variability in persistence with statin use. In general, such reports have been limited by short follow-up periods and modest study populations. Objectives: The aims of this study were to assess long-term persistence with statins and to identify the sociodemographic, clinical, and pharmacotherapy-related factors associated with long-term persistence with statin treatment in first-time users in Israel. Methods: This retrospective cohort study used data from adult enrollees of a not-for-profit health maintenance organization and from death certificates in Israel. Eligible patients initiated statin treatment between 1998 and 2006. Persistence was assessed separately in patients with no indication of a cardiovascular disease (primary prevention) or coronary artery disease (secondary prevention). Treatment persistence and proportion of days covered (PDC) were measured using the interval between the date of the first prescription dispensation (index date) and the point of discontinuation. Results: Data from 229,918 patients were included (primary prevention, 136,052; secondary prevention, 93,866). The PDC was significantly higher in the secondary-prevention group compared with the primaryprevention group (59% vs 45%; P < 0.001). In both cohorts, persistence continually diminished from the index date through follow-up, with ≥75% of patients discontinuing statin therapy by 2 years. Baseline predictors of discontinuation of statin treatment included younger age, female sex, lower socioeconomic status (SES), absence of diabetes or hypertension, no concurrent use of β-blockers or angiotensin-converting enzyme inhibitors, and less health service utilization. New immigrants and patients in the primary-prevention group who had a baseline low-density lipoprotein cholesterol concentration <130 mg/dL were at increased risk for treatment discontinuation. Conclusion: In this study in these patients receiving first-time statin treatment in Israel, we found poor persistence with statins among both the primary- and secondary-prevention cohorts, especially among new immigrants and patients with low SES despite low out-of-pocket prescription costs and free access to health services.