Adherence, persistence, and switching patterns of dabigatran etexilate.

OBJECTIVE: To investigate adherence, persistence, and switching in patients initiating dabigatran. STUDY DESIGN: Descriptive analysis using pharmacy claims databases. METHODS: Patients with a claim for dabigatran and who were continuously enrolled in pharmacy benefits for 180 days prior to and 180 days following the initiation of dabigatran were identified and stratified by whether there was a history of warfarin treatment prior to dabigatran initiation. Medication adherence was calculated as the proportion of days covered (PDC). Persistence to treatment at 180 days was measured. Among patients who discontinued dabigatran, time to initiating warfarin was determined. RESULTS: In the overall population, 39.9% of 17,691 patients were nonpersistent to dabigatran. The PDC for the warfarin-naïve cohort was 0.674 (standard deviation [SD] 0.364), and 0.712 (SD 0.354) for the warfarin-experienced cohort. For patients persistent to dabigatran, the PDCs for warfarin-naïve and warfarin-experienced cohorts were 0.935 (SD 0.075) and 0.937 (SD 0.074), respectively. In patients discontinuing dabigatran, 16.1% of warfarin-naïve and 41.1% of warfarinexperienced patients initiated warfarin. Among patients discontinuing dabigatran, the mean time to discontinuation in warfarin-naïve and warfarinexperienced cohorts, respectively, was 59.8 (SD 36.2) and 59.6 (SD 36.2) days. The mean time to initiating warfarin in warfarin-naïve and warfarin experienced cohorts, respectively, was 62.5 (SD 47.2) and 60.5 (SD 43.0) days. CONCLUSIONS: Two in 5 patients discontinued dabigatran therapy within 6 months, and the majority of these patients were not anticoagulated with warfarin upon discontinuation. These findings highlight potential gaps in the care of patients treated with dabigatran in routine practice.