Association of Patient Frailty With Vestibular Schwannoma Resection Outcomes and Machine Learning Development of a Vestibular Schwannoma Risk Stratification Score

Abstract

BACKGROUND: Patient frailty is predictive of higher neurosurgical morbidity and mortality. However, existing frailty measures are hindered by lack of specificity to neurosurgery. OBJECTIVE: To analyze the association between 3 risk stratification scores and outcomes for nationwide vestibular schwannoma (VS) resection admissions and develop a custom VS risk stratification score. METHODS: We identified all VS resection admissions in the National Inpatient Sample (2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013)(2014)(2015)(2016)(2017). Three risk stratification scores were analyzed: modified Frailty Index-5, modified Frailty , and Charlson Comorbidity Index (CCI). Survey-weighted multivariate regression evaluated associations between frailty and inpatient outcomes, adjusting for patient demographics, hospital characteristics, and disease severity. Subsequently, we used k-fold cross validation and Akaike Information Criterion-based model selection to create a custom risk stratification score. RESULTS: We analyzed 32 465 VS resection admissions. High frailty, as identified by the mFI-11 (odds ratio [OR] = 1.27, P = .021) and CCI (OR = 1.72, P < .001), predicted higher odds of perioperative complications. All 3 scores were also associated with lower routine discharge rates and elevated length of stay (LOS) and costs (all P < .05). Our custom VS-5 score (https://skullbaseresearch.shinyapps.io/vs-5_calculator/) featured 5 variables (age ≥60 years, hydrocephalus, preoperative cranial nerve palsies, diabetes mellitus, and hypertension) and was predictive of higher mortality (OR = 6.40, P = .001), decreased routine hospital discharge (OR = 0.28, P < .001), and elevated complications (OR = 1.59, P < .001), LOS (+48%, P < .001), and costs (+23%, P = .001). The VS-5 outperformed the modified Frailty Index-5, mFI-11, and CCI in predicting routine discharge (all P < .001), including in a pseudoprospective cohort (2018-2019) of 3885 admissions. CONCLUSION: Patient frailty predicted poorer inpatient outcomes after VS surgery. Our custom VS-5 score outperformed earlier risk stratification scores.

Letter: Association of Patient Frailty With Vestibular Schwannoma Resection Outcomes and Machine Learning Development of a Vestibular Schwannoma Risk Stratification Score

“…We read with great interest the recent publication by Tang et al 1 in neurosurgery examining frailty's association with postoperative morbidity and mortality after vestibular schwannoma (VS) resection. We anticipated further frailty and VS discussion after our 2021 publication in JAMA OTO-H&N, 2 which delineated how increasing frailty, and not increasing patient age, was an independent risk factor for postoperative morbidity and mortality, also using the National (Nationwide) Inpatient Sample (NIS).…”

Estimating the causal effect of frailty index on vestibular disorders: A two-sample Mendelian randomization

“…It is becoming increasingly clear that biological aging (vs. chronological aging) contributes to the development of chronic diseases and physical frailty at the molecular and cellular level which can lead to decline and death (Fougere et al, 2017 ). Furthermore, a cross-sectional study has shown that frailty is independently associated with mortality and prolonged hospital stays following vestibular schwannoma resection (Dicpinigaitis et al, 2021 ; Tang et al, 2022 ). Compared with advanced patient age alone, frailty may be more accurate for predicting vestibular schwannoma resection outcomes.…”

In Reply: Association of Patient Frailty With Vestibular Schwannoma Resection Outcomes and Machine Learning Development of a Vestibular Schwannoma Risk Stratification Score

“…Myriad NIS studies across the neurosurgical literature have used these CCS-derived panels to identify perioperative complications. 2,9,10 The authors specifically raise concern for using the "S" identifier among ICD-10 codes to identify operative facial nerve injury. However, the ICD-10 "S" identifier is a direct counterpart to the 800-999 range of codes within the ICD-9 system denoting injury and poisoning.…”

“…We appreciate the insightful letter submitted by Bowers et al 1 in response to our recent article, which used the Nationwide Inpatient Sample to create a custom risk stratification score for vestibular schwannoma (VS) resection outcomes (VS-5). 2 We commend their previous work in establishing how frailty predicts morbidity after VS resection. 3…”

“…We appreciate the insightful letter submitted by Bowers et al 1 in response to our recent article, which used the Nationwide Inpatient Sample to create a custom risk stratification score for vestibular schwannoma (VS) resection outcomes (VS-5). 2 We commend their previous work in establishing how frailty predicts morbidity after VS resection. 3 First, Bowers et al 1 expressed valid concerns regarding differences between the frequencies of preoperative cranial nerve palsies in our cohort, which were calculated using an algorithm from earlier National Inpatient Sample (NIS) neurosurgical studies, 4 and frequencies previously established in the literature, including lower than expected rates of hearing loss and disequilibrium.…”