Patient-reported adherence to statin therapy, barriers to adherence, and perceptions of cardiovascular risk

Background Patient reports of their adherence behaviors, concerns about statins, and perceptions of atherosclerotic cardiovascular disease (ASCVD) risk could inform approaches for improving adherence to statin therapy. We examined these factors and their associations with adherence. Methods We conducted telephone interviews among a stratified random sample of adults receiving statins within an integrated delivery system (N = 730, 81% response rate) in 2010. We sampled equal numbers of individuals in three clinical risk categories: those with 1) coronary artery disease; 2) diabetes or other ASCVD diagnosis; and 3) no diabetes or ASCVD diagnoses. We assessed 15 potential concerns about and barriers to taking statins, and perceived risk of having a heart attack in the next 10 years (0-10 scale). We calculated the proportion of days covered (PDC) by statins in the last 12 months using dispensing data and used multivariate logistic regression to examine the characteristics associated with non-adherence (PDC<80%). Analyses were weighted for sampling proportions. Results Sixty-one percent of patients with PDC<50% reported not filling a new prescription, splitting or skipping statins, or stopping refilling statins in the last 12 months vs. 15% of those with PDC >= 80% (p<0.05). The most commonly reported concerns about statins were preferring to lower cholesterol with lifestyle changes (66%), disliking medications in general (59%), and liver or kidney problems (31%); having trouble remembering to take statins (9%) was the most common reason for taking less than prescribed. In multivariate analyses, clinical risk categories were not significantly associated with odds of non-adherence; however, those with higher perceived risk of heart attack were less likely to be non-adherent. Conclusions Patient-reported medication-taking behaviors were correlated with statin PDC and those with lower perceived cardiovascular risk were less likely to be adherent. These findings highlight the importance of eliciting from and educating patients on their adherence behaviors and ASCVD risks.