Reasons for Nonadherence to the Direct Oral Anticoagulant Apixaban: Cross-Sectional Survey of Atrial Fibrillation Patients

Context: Nonadherence to direct oral anticoagulants to prevent stroke occurs in up to 40% of patients with atrial fibrillation. Underlying reasons are not well understood.

Objectives: Quantify patient-reported reasons for nonadherence and identify potential strategies to improve adherence.

Study Design and Analysis: Cross-sectional survey.

Setting: 2 large academic health systems in Northern and Southern California.

Population Studied: Patients with atrial fibrillation who self-reported nonadherence to apixaban.

Instruments: The survey included questions about reasons for nonadherence to apixaban and an existing validated instrument assessing medication adherence.

Outcome Measure: Relationship between reasons for nonadherence and medication adherence scores (ranging from 0-100, with higher numbers indicating greater adherence) was assessed.

Results: Responses from 419 patients were analyzed. Patients’ mean age was 71.1 (SD=10), 41.5 % were women, and mean CHA2DS2VASc score was 3.2 (SD=1.6). About two-thirds had adherence scores >80 (acceptable adherence), and one-third had scores ≤80 (poor adherence). All groups cited forgetfulness as a contributor to nonadherence. Multivariable logistic regression showed that adherence score ≤80 was associated with: 1) not believing apixaban was needed (OR=2.5; p=0.003); 2) medication cost (OR=1.4; p=0.002); and 3) fear of severe bleeding (OR=1.2; p=0.02). Top strategies that patients with adherence scores ≤80 selected as helping “a great deal/a lot” to increase adherence included blood tests to evaluate efficacy (56%), physician counseling about adherence (55%), and having a reversal agent (39%). Notably, almost half of all patients did not disclose nonadherence to healthcare providers.

Conclusions: Patients may not disclose nonadherence to prescribers, and attitudes related to nonadherence to apixaban differ among patients with acceptable versus poor adherence. While all patients may benefit from strategies to address forgetfulness, concerns related to the purpose of apixaban, cost, and bleeding risk may require special attention in those with poor adherence.