Effects of Frailty Status on Hospitalization Risk and Healthcare Costs among Patients Undergoing Maintenance Haemodialysis: A Retrospective Cohort Study

Background Frailty is common in patients on maintenance haemodialysis(MHD), but its link to healthcare use, is not well understood. This study examined how frailty affects hospitalization outcomes in these patients. Methods A retrospective cohort study at a tertiary teaching hospital in East China examined MHD patients from August 2020 to October 2021. Frailty was assessed using the Fried frailty phenotype, categorizing patients as non-frail, pre-frail, or frail. Participants were monitored until October 1, 2025, focusing on all-cause hospitalization frequency and costs. A negative binomial regression model analyzed the link between frailty and hospitalization frequency, while Tobit regression models assessed the relationship with hospitalization costs. Sensitivity analyses used Fine–Gray competing risk models. Results A total of 738 patients were included. Compared with non-frail patients, pre-frail and frail patients had significantly higher hospitalization frequencies (IRR = 1.59, 95% CI: 1.354–1.890; and IRR = 2.50, 95% CI: 2.063–3.050, respectively; both P < 0.001). Fine–Gray competing risk analyses showed that pre-frail patients had an increased risk of hospitalization (SHR = 1.280, 95% CI: 1.102–1.487;P = 0.001), with frail patients facing an even greater risk (SHR = 1.616, 95% CI: 1.322–1.975; P < 0.001).Tobit regression analyses showed that hospitalization costs rose by an average of USD 5,354 in pre-frail patients and USD 15,400 in frail patients compared to non-frail patients, indicating a dose-response relationship. Log-transformed cost analyses confirmed these results. Conclusions Frailty independently linked to more frequent and costly hospitalizations in MHD patients. Early detection and management could lower healthcare use and costs for this vulnerable group.