Comparative Effectiveness and Safety of Direct Oral Anticoagulants vs Warfarin among Nursing Home Residents with Atrial Fibrillation: A Retrospective Cohort Study

Abstract

Objective

Residents of nursing homes are usually excluded from clinical trials, including trials to assess treatments for common conditions such as nonvalvular atrial fibrillation (NVAF). We aimed to quantify the real-world comparative safety and effectiveness of direct-acting oral anticoagulants (DOACs) vs warfarin among nursing home residents with NVAF.

Design

Retrospective cohort study using 100% national Minimum Data Set and linked Medicare claims from January 2011 through December 2018.

Setting and Participants

Long-term care nursing home residents aged ≥66 years enrolled in fee-for-service Medicare. We included individuals diagnosed with NVAF newly initiating oral anticoagulants.

Methods

We identified exposure to DOACs (apixaban, dabigatran, rivaroxaban, and edoxaban) vs warfarin. Outcomes were hospitalization for ischemic stroke/systemic embolism, major bleeding, pneumonia (negative control outcome), and all-cause death. We used inverse probability of treatment weighting competing risk regression models for clinical outcomes and Cox proportional hazards regression for all-cause death.

Results

Of 38,983 individuals newly initiating anticoagulants, 19,366 (49.7%) initiated DOACs and 19,617 (50.3%) initiated warfarin. In the inverse probability of treatment weighting analysis, compared with warfarin, there was no statistically significant association between DOAC use and ischemic stroke/systemic embolism [4.5 vs 4.7 events per 100 person-years; adjusted hazard ratio (aHR), 0.94; 95% CI, 0.84–1.05] or major bleeding (12.6 vs 12.4 events per 100 person-years; aHR, 1.03; 95% CI, 0.96–1.10). DOACs use was associated with a modest but statistically significant lower risk of all-cause death (48.1 vs 49.0 events per 100 person-years; IPTW analysis aHR, 0.95; 95% CI, 0.91–0.98).

Conclusions and Implications

Among nursing home residents with NVAF, DOACs and warfarin were associated with a similar risk of ischemic stroke/systemic embolism and major bleeding. However, the use of DOACs was associated with a slightly reduced risk of all-cause mortality.