Background: Oral anticoagulation (OAC) is recommended to reduce the risk of stroke or systemic thromboembolism (TE) in atrial fibrillation (AF). In this study, we applied novel joint latent class mixed models to identify heterogeneous patterns of trajectories of OAC use and determined how these trajectories are associated with risks of thromboembolic outcomes.
Methods and results: We used 2013-2016 claims data from a 5% random sample of Medicare beneficiaries, obtained from the Centers for Medicare and Medicaid Services. Our study sample included 16,399 patients newly diagnosed with AF in 2014-2015 who were followed for 12 months after the first AF diagnosis and filled at least one OAC prescription in this time period. OAC use was defined as the number of days covered with OACs every 30-day interval after the first AF diagnosis. We used a joint latent class mixed model to simultaneously evaluate the longitudinal patterns of OAC use and time to stroke or TE, while adjusting for age, race, CHAD2S2-VASc score and HAS-BLED score. Five classes of OAC use patterns were identified: late users (17.8%); late initiators (12.5%); early discontinuers (18.6%); late discontinuers (15.4%); and continuous users (35.6%). Compared with continuous users, the risk of stroke or TE was higher for participants in the late initiators (hazard ratio [HR] 1.73, 95% confidence interval [CI] 1.49-2.01) and late discontinuers (HR 1.23, 95% CI 1.04-1.45) classes.
Conclusion: Late initiators and late discontinuers had a higher risk of stroke or TE than continuous users. Early initiation and continuous OAC use is important in preventing stroke and TE among patients diagnosed with AF.
© 2021. The Author(s), under exclusive licence to Springer Nature Switzerland AG.