Association between the hospital frailty risk score and healthcare resource utilization after total knee arthroplasty: A retrospective observational study

Abstract

Background Total Knee arthroplasty (TKA) is an effective treatment for end-stage knee osteoarthritis (KOA), but healthcare resource utilization has become an increasing concern in an aging surgical population. Hospital Frailty Risk Score (HFRS) has been associated with adverse surgical outcomes, but its impact on resource utilization after TKA remains unclear. Using a large national database, this study aims to evaluate the association between HFRS-defined frailty risk categories and healthcare resource utilization after TKA, including length of stay (LOS), total charges (TOTCHG), and non-routine discharge. Methods Data on patients undergoing TKA were extracted from the National Inpatient Sample database. Patients were categorized into an analytic cohort and a validation cohort. We used the HFRS to identify frailty: low frailty risk (HFRS < 5), intermediate frailty risk (5–15), and high frailty risk (HFRS > 15). Patient demographic, hospital characteristics, and comorbidities were assessed. Logistic regression analyses, stratified analyses, ROC curve analyses, and sensitivity analyses were performed to evaluate associations, subgroup consistency, and discriminative performance. Results A total of 622,574 patients undergoing TKA for primary KOA were identified. Patients were categorized into low (n = 439,343), intermediate (n = 29,637), and high (n = 223) frailty risk groups according to the HFRS. In multivariable logistic regression analyses, higher HFRS-defined frailty risk categories were independently associated with increased healthcare resource utilization and complications. Compared with patients with low frailty risk, those with intermediate and high frailty risk had significantly higher odds of prolonged LOS, increased TOTCHG, non-routine discharge, any complication, and major complications (all P < 0.001). Sensitivity analyses using a binary classification of HFRS-defined frailty yielded consistent findings. Conclusion HFRS-defined frailty risk categories are independently associated with increased healthcare resource utilization and postoperative complications after TKA. These findings support the potential utility of HFRS for preoperative risk stratification and individualized perioperative care planning.