Research Article: Association between medication adherence and illness perceptions in atrial fibrillation patients treated with direct oral anticoagulants: An observational cross-sectional pilot study

Date Published: September 28, 2018

Publisher: Public Library of Science

Author(s): Motoyasu Miyazaki, Akio Nakashima, Yoshihiko Nakamura, Yuya Sakamoto, Koichi Matsuo, Miwa Goto, Masanobu Uchiyama, Keisuke Okamura, Ryoko Mitsutake, Hidenori Urata, Hidetoshi Kamimura, Osamu Imakyure, Michael Nagler.


The aim of this study was to examine the association between medication adherence and illness perceptions, and to explore the factors associated with poor medication adherence in atrial fibrillation (AF) patients receiving direct oral anticoagulants (DOACs) in a real-world clinical setting.

An observational cross-sectional pilot study was conducted at a single Japanese university hospital. One hundred and twenty-nine patients who were diagnosed with AF and who were taking DOACs were recruited from outpatients between January 4th and April 25th, 2017. We evaluated medication adherence to DOACs using the Morisky Medication Adherence Scale-8 (MMAS-8) and illness perceptions using the Brief Illness Perception Questionnaire (BIPQ). The patients’ characteristics and clinical data were collected from electronic medical records.

Ninety-nine (76.7%) patients (male, n = 74; mean age, 71.4±9.8 years) participated in this study. According to the MMAS-8, 21 (21.2%) of the patients were classified into the poor adherence group (MMAS-8 score of <6), and 78 (78.8%) were classified into the good adherence group (MMAS-8 score of 6–8). A multivariate logistic regression analysis revealed that age (per year, odds ratio [OR] 0.912, 95% confidence interval [CI] 0.853–0.965, p = 0.001), a history of warfarin use (OR 0.181, 95% CI 0.033–0.764, p = 0.019), duration of DOAC exposure (per 100 days, OR 1.245, 95% CI 1.084–1.460, p = 0.001), and the BIPQ emotional response score (per 1 point, OR 1.235, 95% CI 1.015–1.527, p = 0.035) were significantly associated with poor medication adherence in AF patients receiving DOACs. Poor medication adherence to DOACs was strongly associated with a stronger emotional response (i.e. stronger feelings of anger, anxiety, and depression), as well as younger age, the absence of a history of warfarin treatment, and longer DOAC exposure. Further evaluation of the factors associated with medication adherence in AF patients and the development and execution of strategies for improving poor adherence are warranted in the real-world clinical setting.

Partial Text

Non-valvular atrial fibrillation (AF) is known as one of the most important risk factors for stroke. Data from the Japanese Circulation Society show that in 2005, approximately 0.7 million people suffered from AF in Japan; by 2050, the number is predicted to increase to 1 million (1.09% of the Japanese population) [1]. Until recently, warfarin was the only agent used to prevent stroke in AF; however, direct oral anticoagulants (DOACs), including dabigatran, rivaroxaban, apixaban, and edoxaban, have been approved for anticoagulation therapy in Japan since 2011. A meta-analysis of clinical trials revealed that DOAC therapy reduced stroke or systemic embolic events by 19% and all-cause mortality by 10% [2]. Unlike warfarin, DOACs have many pharmacological advantages, including a rapid onset/offset of action and a short half-life, predictable pharmacokinetics and pharmacodynamics without the need to constantly monitor the prothrombin time–international normalized ratio (PT-INR), a good safety profile, and fewer drug and food interactions [3]; on the other hand, there have some disadvantages, including high cost and potentially lower treatment motivation due to no PT-INR monitoring as therapeutic index. Therefore, physicians should decide which to prescribe DOACs or warfarin for oral anticoagulant (OAC) therapy depending on the patient’s clinical and psychological characteristics.

In this cross-sectional pilot study, we found that younger age, a lack of previous warfarin treatment, a longer duration of DOAC exposure, and a stronger emotional response (i.e. feelings of anger, anxiety, and depression resulting from AF) were significantly associated with poor adherence in AF patients. To the best of our knowledge, this is the first study to demonstrate a relationship between adherence to DOACs and illness perceptions in AF patients.




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