Statement of the problem: Oral anticoagulants (AC) reduce the risk of ischemic stroke (IS) in older adults with atrial fibrillation (AF) but increase the risk of major hemorrhage. Treatment with ACs requires prescribers and patients to weigh benefits against risks. Many older adults with AF residing in long-term care (LTC) facilities may not be using ACs, even in the absence of absolute contraindications. This study (1) examined the prevalence of AC use, (2) assessed which factors were associated with AC use, and (3) estimated the net effect of ACs weighing the benefit (IS prevention) against the risk (intracranial hemorrhage [ICH]) in older adults with AF residing in LTC facilities.

Methods: An observational cohort study was performed using a 5% random sample of older adults with AF residing in LTC facilities for at least 101 days from 2007 to 2013 using a Medicare administrative claims database linked to the Minimum Dataset assessments.

Results: Of the 21,877 Medicare beneficiaries meeting the study eligibility criteria, over half (54.6%) were 85 years or older, most were female (75.9%) and white (88.1%). The prevalence of AC use was 36.2% (95% confidence interval [CI]: 35.6%-36.8%). History of stroke or transient ischemic attack and history of thromboembolism were associated with an increased likelihood of AC use, while history of internal bleed was associated with a decreased likelihood of AC use. The net effect of AC use was 1.07 per 100 person-years, 95% CI: 0.31-3.01; this is the difference between, on the one hand, the difference in the estimated rate of IS while not using ACs and using ACs and, on the other hand, the difference between the estimated rate of ICH while using ACs and not using ACs .

Conclusions: The majority of older adults with AF residing in LTC facilities are not being managed with ACs. While this study provides evidence suggestive of a net benefit of AC use in older adults with AF residing in LTC facilities, health status and the burden of medication monitoring are among the other factors that patients, their caregivers and providers should consider when making the decision about initiating ACs.