Adherence to Oral Anticoagulant Medications

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

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.

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.

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.

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.