Background: Although several meta-analyses have examined the effects of off-label underdosing of nonvitamin K antagonist oral anticoagulants (NOACs) compared with their recommended doses in patients with atrial fibrillation (AF), they combined different kinds of NOACs in their primary analyses. Herein, we first conducted a meta-analysis to separately assess the effects of off-label underdosing versus on-label dosing of four individual NOACs on adverse outcomes in the AF population.
Methods: The PubMed and Embase database were systemically searched until November 2021 to identify the relevant studies. Adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were pooled by utilizing a random-effects model.
Results: A total of nine studies with 144,797 patients taking NOACs were included in the meta-analysis. In the pooled analysis, off-label underdosing of rivaroxaban was related to an increased risk of stroke or systemic embolism (HR = 1.31, 95% CI 1.05-1.63; p = .02), whereas off-label underdosing of apixaban was associated with a higher risk of all-cause death (HR = 1.21, 95% CI 1.05-1.40; p = .01). When comparing off-label underdosing versus on-label dosing of dabigatran or edoxaban, no differences were found in the primary and secondary clinical outcomes.
Conclusion: Off-label underdosing of rivaroxaban may increase the risk of stroke or systematic embolism, whereas off-label underdosing of apixaban may heighten the incidence of all-cause death.
Keywords: atrial fibrillation; meta-analysis; nonvitamin K antagonist oral anticoagulants; off-label; underdosing.
© 2022 Stichting European Society for Clinical Investigation Journal Foundation. Published by John Wiley & Sons Ltd.