Predictors of non-adherence to and non-persistence with statin therapy among patients on oral diabetes medication in the netherlands: A retrospective inception cohort study

Background: The use of statins as the most extensively used lipid-lowering therapy is known to be suboptimal in daily practice. Few studies, however, have looked at non-adherence and non-persistence as distinct phenomena. Objectives: To evaluate statin adherence and persistence rate, and to identify potential predictors associated with statin non-adherence and non-persistence among patients on oral diabetes medication. Methods: We conducted a cohort study of statin starters using the pharmacy database IADB.nl. We included patients on oral diabetes medication aged 40 years and older at the start of statin treatment between 1994 and 2014. Adherence and persistence rates were measured during a 3-year follow-up. Patients were considered non-persistent when there was a gap of ≥180 days after the end of a prescription. Adherence rates were calculated as the proportion of days covered (PDC) for persistent patients. Patients with a PDC