Objective: To compare the risk of hospitalization and costs associated with major bleeding (MB) or stroke/systemic embolism (SE) among elderly patients with nonvalvular atrial fibrillation (NVAF) who initiated apixaban then switched to another oral anticoagulant (OAC) vs. those who continued with apixaban treatment. Methods: NVAF patients (≥65 years) initiating apixaban were identified from the Humana database (1 January 2013-30 September 2017) and grouped into switcher and continuer cohorts. For switchers, the earliest switch from apixaban to another OAC was defined as the index event/date. A random date during apixaban treatment was selected as the index date for continuers. Patients were followed from index date to health plan disenrollment or 31 December 2017, whichever was earlier. Multivariable regression analyses were used to examine the association of switchers vs. continuers with risk of MB-related or stroke/SE-related hospitalization and healthcare costs during follow-up. Results: Of 7858 elderly NVAF patients included in the study, 14% (N = 1110; mean age: 78 years) were switchers; 86% (N = 6748; mean age: 79 years) were continuers. Apixaban switchers vs. continuers had significantly greater risk of MB-related hospitalization (hazard ratio [HR]: 2.00; 95% CI: 1.52-2.64; p < .001) during follow-up; risk of stroke/SE hospitalization did not differ significantly (HR: 1.36, 95% CI: 0.89-2.06, p = .154). MB- and stroke/SE-related medical costs were higher for switchers vs. continuers, although total all-cause healthcare costs were similar. Conclusion: Elderly patients with NVAF in the US who continued with apixaban treatment had a lower risk of MB-related hospitalization and lower MB- and stroke/SE-related medical costs compared to patients who switched to another OAC.
Keywords: Apixaban; continue treatment; hospitalization; major bleeding; nonvalvular atrial fibrillation; oral anticoagulant; stroke; switch treatment; systemic embolism.