Adherence to Oral Anticoagulant Medications

Abstract

Background: Oral anticoagulants (OAC) reduce the risk for stroke and death from all causes in patients with non-valvular atrial fibrillation (NVAF).

Objectives: To explore adherence rates of OAC among patients with NVAF in long-term use in a real-world setting and to examine patient characteristics associated with good adherence.

Methods: We conducted a population-based cohort study with members of Clalit Health Services, Israel. All patients aged ≥ 30 years with a diagnosis of NVAF before 2016 who were treated with OAC were included. We included patients who filled at least one prescription per year in the three consecutive years 2016-2018. We analyzed all prescriptions that were filled for the medications from 1 January 2017 to 31 December 2017. We considered purchasing of at least nine monthly prescriptions during 2017 as good medication adherence.

Results: We identified 26,029 patients with NVAF who were treated with OAC; 10,284 (39.5%) were treated with apixaban, 6321 (24.3%) with warfarin, 6290 (24.1%) with rivaroxaban, and 3134 (12.0%) with dabigatran. Rates of good medication adherence were 88.9% for rivaroxaban, 84.9% for apixaban, 83.6% for dabigatran, and 55.8% for warfarin (P < 0.0001). Advanced age was associated with higher adherence rates (P < 0.001). Socioeconomic status was not associated with medication adherence. Good adherence with OAC was associated with lower low density lipoprotein (LDL) cholesterol and glucose levels.

Conclusions: Adherence rates to OAC in chronic use among patients with chronic NAVF are high. Investing in OAC adherence may have a wider health impact than expected.