Aim: Polypharmacy in multimorbid older patients with atrial fibrillation (AF) is a risk factor for potentially inappropriate prescribing (PIP). We aimed to systematically assess the evidence on the prevalence of PIP and its impact on adverse health outcomes in this patient group.

Methods: A systematic search of the published peer-reviewed literature describing the prevalence of PIP and/or its association with adverse health outcomes in multimorbid (AF plus one comorbidity) and polymedicated (≥ 2 drugs) adults ≥ 65 years was done up to March 2023. A meta-analysis of the prevalence of PIP of (direct) oral anticoagulants ((D)OACs) was conducted using a random-effects model. Leave-one-out analysis was performed with R (version 4.2.2) and RStudio (version 2022.12.0+353).

Results: Of the 12 studies included, only one reported on the prevalence of overall PIP (65%). The meta-analysis of 10 studies assessing PIP of (D)OACs produced a pooled prevalence [95% confidence interval (CI)] of 35% [30-40%], with significant heterogeneity between the included studies (I(2) 95%). No statistically significant association was reported in three studies between PIP of (D)OACs, cardiovascular (CV) and all-cause mortality, hospital readmission, CV hospitalisation and stroke. Reported associations between PIP and major bleeding differed, with one study demonstrating a significant association (odds ratio 2.17; 95% CI 1.14-4.12) and the other study not showing such association.

Conclusion: This systematic review highlights the scarce evidence regarding the prevalence of PIP and its association with adverse health outcomes in multimorbid older adults with AF. Large, prospective and better-designed studies are needed.