A systematic review to assess adherence and persistence with statins

Objective: To identify and assess studies published over a 10 year period up to February 2016 which measure adherence or persistence with statins, to summarize their methods, strengths and weaknesses and to summarize evidence linking statin adherence/persistence with risk of cardiovascular events. Methods: Electronic databases and abstracts from four major cardiovascular disease conferences were searched from January 2005 to February 2016. The study selection process was performed by two reviewers working independently. Studies were included if they reported data regarding patient adherence or persistence with statins in adults with primary hypercholesterolemia, using any type of study design or length of follow-up. One reviewer extracted the study data and assessed study quality, which was checked by a second reviewer independently. Given the heterogeneity between the included studies a narrative critique and summary is presented. Results: We report on 84 real world studies which aimed to assess adherence or persistence with statins. The majority of studies concluded that good adherence/persistence was associated with reduction in cardiovascular events and mortality. In two studies high intensity statin regimens were associated with poorer patient adherence when compared to low intensity statins. Adherence and persistence with statin therapy also has an impact on hospitalization costs and other cardiovascular disease (CVD) related costs. Conclusions: Adherence and persistence are associated with a reduction in CVD events and mortality. There was limited evidence to suggest that high intensity statin regimens are associated with poorer treatment adherence when compared to lower intensity regimens. Hence, more robust studies are required to establish this association. As recommended by the 2013 ACC/AHA, 2016 ESC and several other clinical guidelines, clinicians and pharmacy managers should regularly monitor statin therapy adherence.