The Risk Analysis Index Has Superior Discrimination Compared With the Modified Frailty Index-5 in Predicting Worse Postoperative Outcomes for the Octogenarian Neurosurgical Patient

Abstract

BACKGROUND AND IMPORTANCE: Healthcare systems continuously strive to improve quality and value of care. Advances in surgical technologies, enhanced perioperative surgical planning, and multidisciplinary care strategies are increasing the number of elective procedures in the geriatric population. However, frail older adults are still more likely to have poor postoperative outcomes. We examined the impact of frailty on postoperative outcomes, we compared the discriminative thresholds for the Risk Analysis Index (RAI), modified Frailty Index-5 (mFI-5), and increasing patient age. CLINICAL PRESENTATION: Octogenarian patients undergoing spine, cranial, and other procedures captured in the American College of Surgeons National Surgical Quality Improvement Program between 2012 and 2020 were included. We used receiver operating characteristic curve to examine discriminative thresholds of RAI, mFI-5, and increasing patient age. Multivariable analyses were performed. Our primary outcomes were 30-day mortality, extended length of stay (eLOS [≥75th percentile]), and continued inpatient care >30 days (pLOS). Secondary outcomes were skilled care facility (skilled nursing facility [SNF]) discharges and readmissions. DISCUSSION: In total, 20 710 octogenarians were included, with a mean age of 83 years (SD, 2.5) and a men (52.7%) and White (79.8%) majority. The RAI had higher predictive discriminative thresholds for 30-day mortality (C-statistic of 0.743), eLOS (C-statistic: 0.692), and pLOS (C-statistic: 0.697) compared with the mFI-5 (C-statistic: 0.574, 0.556, and 0.550, respectively), and increasing patient age (C-statistic: 0.577, 0.546, and 0.504, respectively), P < .001. On multivariable analyses, RAI showed a larger effect size with adverse postoperative outcomes by increasing frailty strata than mFI-5 and increasing patient age. Nonetheless RAI showed decreased risk for SNF discharges. CONCLUSION: We found that RAI was a more accurate predictor than mFI-5 and increasing patient age for 30-day mortality, eLOS, and pLOS in octogenarian neurosurgery patients. More research is needed on RAI's performance in different specialized neurosurgical populations. Moreover, it is increasingly clear that comprehensive risk assessment strategies tailored to optimize perioperative care should be prioritized to potentially improve outcomes for this at-risk population.