OBJECTIVE: To evaluate comparative effectiveness and safety of non-vitamin-K antagonist oral anticoagulants (NOACs) versus warfarin in Medicare beneficiaries with non-valvular atrial fibrillation (NVAF) and comorbid diabetes mellitus (DM).
METHODS: A retrospective cohort study using 2014-2016 5% national Medicare data was undertaken. NVAF patients with DM aged ≥65 years having at least one prescription for NOACs or warfarin between July 2014 and December 2015 were included in the study. Propensity score matching was used to balance demographic and baseline clinical characteristics of patients in two treatment groups. Cardiovascular outcomes including stroke/systemic embolism (SE) and myocardial infarction (MI) were evaluated to measure effectiveness. Assessment of safety outcomes included intracranial hemorrhage (ICH), major gastrointestinal bleeding (MGB), bleeding from other sites (OB) and all-cause mortality. Stratified Cox proportional hazards models were used to estimate hazard ratios for the outcomes in the matched cohort.
RESULTS: The matched sample consisted of 4582 patients (2291 pairs). Compared to warfarin, NOACs had a significantly lower risk of stroke/SE (hazard ratio (HR): 0.373, 95% confidence interval (CI): 0.247-0.564, p < .001) and all-cause mortality (HR: 0.783, CI: 0.656-0.873, p = .007). NOACs were found to significantly reduce the risk of ICH (HR: 0.500, CI: 0.300-0.834, p = .008) and OB (HR: 0.608, CI: 0.424-0.870, p = .007), but no difference was observed in the risk of MGB (HR: 0.862, CI: 0.640-1.160, p = .326) between NOACs and warfarin. The composite outcome demonstrated superior overall effectiveness and safety of NOAC therapy compared to warfarin therapy (HR: 0.685, CI: 0.587-0.801, p < .001).
CONCLUSION: Oral anticoagulation therapy with NOACs was found to be more effective than warfarin therapy among older adults with NVAF and comorbid DM.
