# Factors influencing the inappropriate dosing of rivaroxaban and edoxaban in Chinese hospitalized patients with atrial fibrillation

## TL;DR

This study found that many Chinese patients with atrial fibrillation receive incorrect doses of anticoagulants like rivaroxaban and edoxaban, with age, antiplatelet drug use, and lack of dronedarone being key factors.

## Contribution

The study identifies specific clinical factors associated with inappropriate dosing of DOACs in Chinese AF patients using real-world data.

## Key findings

- 53.8% of patients received inappropriate DOAC dosing, with rivaroxaban underdosing being most common.
- Advanced age, antiplatelet drug use, and nonuse of dronedarone were independently linked to inappropriate dosing.
- Underdosing was more prevalent than overdosing for both rivaroxaban and edoxaban.

## Abstract

Inappropriate dosing of direct oral anticoagulants (DOACs) may increase the risk of thromboembolism or bleeding in patients with atrial fibrillation (AF). The inappropriate use of these medications presents a significant clinical challenge. Our study aimed to analyze the current utilization of rivaroxaban and edoxaban among Chinese patients with AF, as well as the factors influencing the use of nonstandard doses.

This study evaluated patients diagnosed with AF between January 2017 and December 2023. Descriptive analyses were performed to summarize the characteristics of the study population. Inappropriate dosing was identified based on the guidelines. Multivariate analysis was performed to identify factors associated with inappropriate dosing in these patients.

A total of 1,066 patients diagnosed with AF, comprising 852 individuals treated with rivaroxaban and 214 individuals treated with edoxaban, were included. Their median age was 69 years, and 58.7% of them were males. Among them, 573 patients (53.8%) received inappropriate dosages. Among the patients prescribed rivaroxaban, 503 (59.0%) were underdosed and eight (0.9%) were overdosed. Among the patients prescribed edoxaban, 49 patients (22.9%) were underdosed and 13 patients (6.1%) were overdosed. Multivariate analysis identified independent factors associated with inappropriate medication dosing, including advanced age [adjusted odds ratio (OR) 1.031, 95% confidence interval (CI) 1.010–1.052], combined use of antiplatelet drugs (adjusted OR 1.649, 95% CI 1.111–2.447), and reduced use of dronedarone (adjusted OR 0.332, 95% CI 0.126–0.877).

The incidence of inappropriate DOAC dosing in Chinese patients with AF was high. Advanced age, the concurrent use of antiplatelet medications, and the nonuse of dronedarone have been identified as independent factors associated with inappropriate dosing.