Medication Adherence to Oral Anticoagulants Among Persons with Atrial Fibrillation : A Systematic Review

Abstract

Medication adherence to oral anticoagulants represents a critical cornerstone in the clinical management of patients with atrial fibrillation, as this medical condition carries an exceptionally high risk of intracardiac thrombus formation due to blood stasis in the fibrillating atria. These formed thrombi may subsequently dislodge and embolize to the cerebral vasculature or other vital peripheral organs, leading directly to ischemic stroke, paresis, or paralysis; in some cases, these severe complications can even be fatal. Preventing such catastrophic adverse events fundamentally necessitates strict, consistent, and continuous adherence to prescribed anticoagulant regimens. However, current evidence indicates that patients still exhibit suboptimal and inconsistent medication adherence, thereby escalating the risk of subsequent complications and increasing the overall economic burden on healthcare systems. Consequently, the explicit objectives of this study were: 1) to review the current situation, analyze, synthesize, and summarize existing research regarding medication adherence to oral anticoagulant therapy among patients with atrial fibrillation, alongside the multifaceted factors influencing such adherence; and 2) to present the synthesized insights toward developing evidence-based nursing guidelines that promote sustainable patient adherence and foster effective engagement in self-management capabilities.

A comprehensive literature review search was rigorously conducted across five prominent electronic databases: PubMed, ScienceDirect, Scopus, Wiley Online Library, and ThaiJO. The database search covered ten years from 2014 to 2024 and utilized specific keywords,such as "anticoagulants," "medication adherence," and "atrial fibrillation." An initial total of 1,609 research articles were identified. Following a multi-stage title and abstract screening process to eliminate duplicates and irrelevant studies, the remaining full-text articles underwent rigorous quality appraisal and methodological evaluation based on the standardized Joanna Briggs Institute (JBI) critical appraisal guidelines. Ultimately, 10 high-quality studies successfully met all predetermined inclusion and exclusion criteria, comprising 1 comprehensive systematic review and 9 robust non-experimental, observational studies.

The findings revealed that the majority of patients exhibited low levels of medication adherence, a phenomenon particularly pronounced among those prescribed warfarin; this was primarily due to the complex requirements for routine international normalized ratio (INR)laboratory monitoring, alongside strict dietary restrictions and potential drug-drug interactions,which collectively disrupted regular medication intake and heightened patient anxiety. In contrast,patients receiving non-vitamin K antagonist oral anticoagulants (NOACs) demonstrated significantly higher and more stable levels of adherence, owing to a streamlined, predictable therapeutic regimen that eliminates the logistical burden of routine blood monitoring and presents fewer dietary and pharmacological restrictions, thereby seamlessly integrating into their daily lives and rendering patients more likely to adhere to their treatment. Furthermore, the factors influencing medication adherence are multifaceted and encompass various dimensions. These include social factors, such as family support, which promotes regular medication intake; and demographic factors, such as age, with findings indicating that older adults tend to exhibit higher adherence rates. Additionally, knowledge and beliefs regarding medication—such as a correct understanding of the dosage regimen, beliefs about the necessity of medication, and perceived barriers to medication adherence—are significantly associated with medication adherence. It was also found that other clinical factors, including comorbidities, type of medication, complexity of the therapeutic regimen, polypharmacy, and duration of treatment, were significantly associated with patient medication adherence.

The findings suggest that adherence to oral anticoagulant therapy is a complex and dynamic behavior influenced by multiple interconnected factors, including patient-related,treatment-related, healthcare provider-related, and healthcare system-related factors. Therefore,promoting consistent medication adherence cannot rely on a single approach. Instead, it requires a systematic assessment of individual barriers and facilitators, taking into account patients’ living contexts and daily circumstances. In addition, individualized educational interventions are needed to enhance patients’ knowledge and understanding of their disease and treatment. Continuous monitoring and evaluation, together with the active involvement of family members and multidisciplinary healthcare teams, are essential to support long-term adherence. Such comprehensive strategies may reduce the risk of thromboembolic events and enhance patient safety. Ultimately, the findings of this review can inform the development of evidence-based nursing guidelines and tailored clinical care pathways for patients with atrial fibrillation. By emphasizing patient education, improving treatment understanding, and promoting active patient engagement in shared decision-making with healthcare providers, these guidelines may support improved long-term medication adherence and reduce the risk of thromboembolic complications.In addition, this approach may contribute to enhanced patient safety and improved quality of life.

Keywords: Anticoagulant, Atrial fibrillation, Medication adherence

Author Contributions:
JV: Conceptualization, Method and design, Data collection and analysis, Writing and revising the manuscript
NU: Conceptualization, Method and Design, Supervision, Data analysis and interpretation, Editing and revising the manuscript, Corresponding with the editor-in-chief