Longitudinal Oral Anticoagulant Adherence Trajectories in Patients With Atrial Fibrillation.

Background: Conventional adherence summary measures do not capture the dynamic nature of adherence.
Objectives: This study aims to characterize distinct long-term oral anticoagulant adherence trajectories and the factors associated with them in patients with atrial fibrillation.
Methods: Adults with incident atrial fibrillation were identified using linked population-based administrative health data in British Columbia, Canada (1996-2019). Group-based trajectory modeling was used to model patients' 90-day proportions of days covered over time to identify distinct 5-year adherence trajectories. Multinomial regression analysis was used to assess the effect of various demographic and clinical factors on exhibiting each adherence trajectory.
Results: The study cohort included 19,749 patients with AF (mean age: 70.6 ± 10.6 years), 56% male, mean CHA ₂ DS ₂ -VASc stroke risk score 2.8 ± 1.4. Group-based trajectory modeling identified 4 distinct oral anticoagulants adherence trajectories: "consistent adherence" (n = 14,631, 74% of the cohort), "rapid decline and discontinuation" (n = 2,327, 12%), "rapid decline and partial recovery" (n = 1,973, 10%), and "slow decline and discontinuation" (n = 819, 4%). Very few patient variables were found to be associated with specific adherence trajectories.
Conclusions: There is heterogeneity among nonadherent patients in the rate and timing of decline in their medication taking. Clinical and demographic characteristics were found to be inadequate to predict patients' adherence trajectories. Insights from this study could be used to inform the design and timing of adherence interventions, and qualitative studies may be needed to better understand the psychosocial determinants and reasons for the behaviors reflected in the identified trajectories.
Competing Interests: Funding Support and Author Disclosures This research was supported by Canadian Institutes of Health Research grant (FRN 168896). All inferences, opinions and conclusions drawn in this manuscript are those of the authors, and do not reflect the opinions or policies of the Data Steward(s). Dr Loewen’s research is also partially supported by the UBC David H MacDonald Professorship in Clinical Pharmacy (Vancouver, Canada). Dr Salmasi’s PhD studies are supported by the International Doctoral Fellowship from the University of British Columbia (Vancouver, Canada). Dr Andrade has received honoraria from Bayer, Biosense Webster, BMS Pfizer, Medtronic, and Servier; and has received grants from Baylis, and Medtronic. Dr Deyell has received honoraria from Pfizer, Servier, and Bayer. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
(Copyright © 2021 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)