Patient-reported Barriers to Statin Therapy Adherence

Background: Non-adherence to statin therapy is associated with poor cardiovascular outcomes; however, there is limited information on the barriers that limit patient adherence. Methods: We conducted telephone interviews with a stratified random sample of adults receiving statin therapy within an integrated delivery system (N=730, 81.5% response rate). We oversampled patients with low adherence based on the proportion of days covered using automated pharmacy data. We assessed self-reported adherence, and 15 concerns and potential barriers to adherence (e.g., costs, convenience, side-effects, and lifestyle concerns). We used logistic regression to examine predictors of non-adherence and weighted all analyses for sampling proportions. Results: Overall, 17.7% reported splitting or skipping statin pills without their doctor's advice, 4.8% stopped refilling their statin prescription, and 3.1% did not fill a new statin prescription in the previous 12 months; 21.8% reported any of these behaviors. Patients reported a range of concerns, the most common were preferring to lower cholesterol with lifestyle changes such as diet or exercise (65.7%), generally disliking taking medications (58.6%), and concerns about liver or kidney problems associated with statin use (30.9%). In multivariate analyses, younger subjects, and those unsure of the benefits of statins, reporting logistical problems, and having risk/side-effect concerns were more likely to report poor adherence (all p<0.05); having lifestyle concerns (e.g., preferring diet/exercise, disliking medications in general) was not significantly associated with poor adherence. Conclusions: Patients face a range of barriers to statin adherence. Better understanding these factors is critical for designing effective interventions to improve adherence.