Background. Frailty is common in older patients, and it has been suggested to occur more frequently and with greater severity in women compared to men. In older people with atrial fibrillation (AF), frailty has been shown to influence the prescriptions of oral anticoagulants (OAC) and patient outcomes. Aim. To examine the prevalence of frailty in older patients with AF and the association between frailty with OAC prescription and hospitalization, with a particular focus on variations by sex. Methods. Adults aged 60 years or older with AF were recruited at the outpatient clinics of two major hospitals in Vietnam between December 2022 and May 2024. Frailty was defined by the 9-item Clinical Frailty Scale (CFS) with a cut-point of 5. Logistic regression models were applied to examine the association between CFS score with OAC prescription and cardiovascular disease (CVD) related hospitalization over 6 months. Results are presented as odds ratios (ORs) and 95% confidence intervals (CIs). An interaction term was added to the models to obtain the women-to-men ratios of ORs and 95% CIs, which were used to quantify how the ORs differed between the sexes. Results. A total of 1210 patients (513 women, 697 men) were included in this analysis. They had a mean age of 73.7 (SD 8.9) years. The mean CFS score was 4.1 (SD 1.2). The prevalence of frailty was 40.7% across all participants, 46.8% in women vs. 36.3% in men, p<0.001. Women were older (mean age 74.6/SD 8.9 vs 73.0/SD 8.8 in men, p=0.004), had higher CHA₂DS₂-VASc score (4.2/SD 1.3 vs 3.2/SD 1.3 in men, p<0.001) and HASBLED score (1.6/SD 0.8 vs 1.4/SD 0.8 in men, p=0.004). OAC prescription rate was 90.7% across all participants and lowest among frail women (83.8%). With every unit increase in the CFS, the adjusted ORs for OAC prescription were 0.70 (95%CI 0.54 to 0.90) in women, 0.97 (95%CI 0.74 to 1.28) in men (women to men ratio of ORs 0.72, 95%CI 0.50 to 1.05). During the 6-month follow up, the CVD hospitalization rate was 14.3%. CFS score predicted CVD hospitalization, with adjusted ORs of 1.65 (95%CI 1.29 to 2.10) in women, 2.04 (95%CI 1.62 to 2.59) in men; women to men ratio of ORs 0.81 (95%CI 0.58 to 1.13). Conclusion. In older patients with AF, frailty was more common and was associated with reduced odds of receiving OAC in women. Frailty increased the risk of CVD hospitalization for both women and men, although its impact on hospitalization tends to be greater in men. Further studies are needed to confirm these findings.

The authors have declared no competing interest.

This study did not receive any funding.

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

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The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

The studies were approved by the Ethics Committee of the University of Medicine and Pharmacy at Ho Chi Minh City (Reference Number 1027/HDDD-DHYD, dated 09/12/2022) and the Ethics Committee of Thong Nhat Hospital (Reference Number 87/2022/BVTN-HĐYĐ, dated 25/11/2022). Informed consent was obtained from all participants.

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All data produced in the present study are available upon reasonable request to the authors.