Self-reported adherence to anticoagulation and its determinants using the Morisky medication adherence scale

Area of Science:

• Pharmacology
• Clinical Pharmacy
• Internal Medicine

Background:

• Direct oral anticoagulants (DOACs) are crucial for venous thromboembolism (VTE) and atrial fibrillation (AF) stroke prevention.
• Adequate adherence to DOACs is vital due to their shorter half-life and lack of routine laboratory monitoring compared to vitamin-K antagonists (VKAs).
• Current clinical practice data on anticoagulation adherence remains unclear.

Purpose of the Study:

• To evaluate self-reported anticoagulation adherence among patients treated at a tertiary anticoagulation clinic.
• To compare adherence rates between DOACs and VKAs.
• To identify factors associated with anticoagulation adherence.

Main Methods:

• A cross-sectional study was conducted involving patients on oral anticoagulants (VKAs, rivaroxaban, dabigatran, apixaban).
• The 4-item Morisky score was utilized to assess self-reported anticoagulation adherence.
• Baseline patient characteristics were analyzed for their association with adherence levels.

Main Results:

• The study included 500 patients: 74% on VKAs and 26% on DOACs (rivaroxaban, dabigatran, apixaban).
• Primary indications were VTE (72%) and AF (18%).
• Self-reported adherence was 56.2% for VKAs and 57.1% for DOACs. Significant predictors of adherence included older age, female gender, concurrent use of other oral medications, and retired employment status.

Conclusions:

• Self-reported anticoagulation adherence rates were comparable between VKA and DOAC users.
• Physicians should consistently emphasize the importance of anticoagulation adherence during patient interactions, especially pending universal DOAC laboratory assay availability.
• The Morisky scale offers a straightforward method for assessing adherence, though its validation for this specific purpose requires further investigation.