Medication adherence and treatment persistence following switching from vitamin K antagonists to direct oral anticoagulants: a systematic review.

What was studied

This review looked at adherence and persistence after a drug switch. Patients moved from VKAs to DOACs. VKAs are vitamin K antagonists. DOACs are direct oral anticoagulants. The switch is now more common. The team also listed the reasons for switching. They searched PubMed and Scopus for studies from January 2016 to April 2026. They followed PRISMA guidelines. The studies covered adults with atrial fibrillation, venous thromboembolism or other needs for anticoagulation.

What they found

Adherence was measured by refill data and by patient-reported tools. Refill-based adherence was generally moderate to high. Most studies counted patients with a proportion of days covered (PDC) of 80 or more. That share ranged from 76 to 97.5. Patient-reported tools gave more variable adherence. Persistence ranged from 54 to 94. Definitions and follow-up times varied. This limited direct comparison. The top reasons for switching were poor INR control and low time in therapeutic range.

What it means for patients

The team says objective adherence was generally moderate to high after switching. Persistence and patient-reported adherence varied more. They say methods differed across studies. They point to a need for standard evaluation approaches and continued adherence support.

Why it is not certain yet

Persistence definitions and follow-up times varied. This limited direct comparison across studies. The studies were synthesized in words, not pooled. A review can only be as good as the studies in it.

Source

Medication adherence and treatment persistence following switching from vitamin K antagonists to direct oral anticoagulants: a systematic review.

We restate facts from the source record in our own words. The original wording belongs to its publisher.