Impact of frailty on all-cause mortality in older neurosurgical patients with prolonged hospitalization: a retrospective observational study

Hospital performance is increasingly measured by length of stay, which accounts for 90% of inter-patient cost variations. We examined the impact of frailty on all-cause mortality in neurosurgical patients with length of stay > 30 days and analyzed the discrimination and independent association of the risk analysis index, 5-factor modified frailty index, and advanced patient age for predicting all-cause mortality. The older patients who underwent neurosurgical procedures between 2012 and 2020 in the American College of Surgeons National Surgical Quality Improvement Program, with length of stay > 30 days were included in this retrospective observational study. Receiver operating characteristic curves were employed to compare the discrimination and multivariable analyses for associations of the risk analysis index, 5-factor modified frailty index advanced patient age and all-cause mortality. Secondary analyses were performed for spine and cranial procedures. Overall, 3474 patients were included, patients had a median age of 60 years (IQR: 49–70), were male (58.6%), white (47.9%), and underwent spine (46.4%) and cranial (51.9%) procedures. Major complications (33.9%), and median length of stay 38 days (IQR: 33–48) were observed. Risk analysis index demonstrated superior discrimination (C-statistic 0.72, 95% confidence interval 0.69–0.74) than 5-factor modified frailty index (C-statistic 0.57, 95% confidence interval 0.54–0.60) and advanced patient age (C-statistic 0.59, 95% confidence interval 0.55–0.62). Risk analysis index also demonstrated a dose-dependent relationship and larger effects in multivariable analysis ( P < 0.001). Similar trends were observed for spine and cranial procedures in both Receiver operating characteristic and multivariable analysis. Taken together, frailty increased all-cause mortality dose-dependently, and risk analysis index exhibited a higher discrimination threshold and larger effect estimates than the 5-factor modified frailty index and advanced patient age. This study reflects the importance of preoperative assessment of frailty in the management of older neurosurgical patients and supports the use of risk analysis index in preoperative assessment to improve clinical outcomes of older patients. By identifying and assessing frailty, healthcare professionals can better personalize treatment plans for older patients to address age-related changes and challenges.