2025 Volume 56 Issue 2 Pages 81-87
The incidence of stroke including cerebral embolism with atrial fibrillation (AF) is very high among the Japanese population. Although direct oral anticoagulants (DOACs) have become widely used in recent years, their adherence and compliance rates are unclear. Therefore, we conducted a multicenter study to investigate medication adherence among outpatients treated with oral anticoagulant therapy in Tochigi Prefecture. The subjects were 500 outpatients who were receiving oral anticoagulant treatment with warfarin or DOAC at insurance dispensing pharmacies, i.e., collaborating institutions, in the prefecture. Patients who consented to the study were asked to complete a self-administered questionnaire between December 2019 and February 2020. A total of 462 survey forms were collected from 10 pharmacies. Of these, all 462 cases were evaluated and analyzed; 280 patients (60.6％) were suffering from AF and 20 patients (4.3％) had venous thromboembolism. The most common reason for missed doses was simply forgetting to take the medication (115 patients, 24.9％), and a small number of patients (9 patients, 1.9％) reported that they had not taken any medication. Less than 10％ of the patients (8.4％) requested medication counselling. Next, with respect to medication compliance, 424 (91.8％) of the 462 patients had good compliance and 18 (3.9％) had poor compliance. The proportion of non-adherent patients with twice-daily dabigatran was higher (14.3％) than with other oral anticoagulants and significantly greater than that with once-daily DOAC (p＝0.014). AF was highly associated with poor medication adherence (odds ratio: 3.91, 95％ confidence interval: 0.88-17.25). The relatively high medication adherence rate in this survey may have been due to the self-reporting by patients, which may be supported by the fact that the survey was conducted with highly adherent patients. It may be necessary in the future to conduct adherence surveys using other objective methods.
