A comparison of frailty indices in predicting length of inpatient stay and discharge destination following angiogram-negative subarachnoid hemorrhage

Abstract

Background and Purpose While patients with angiogram-negative subarachnoid hemorrhages (ANSAH) have better prognoses than those with aneurysmal SAH, frailty’s impact on outcomes in ANSAH is unclear. We previously showed that the modified frailty index (mFI-11) is associated with poor outcomes following ANSAH. Here, we compared the mFI-5, mFI-11, Charlson Comorbidity Index (CCI), and temporalis thickness (TMT) to determine which index was the best predictor of ANSAH outcomes and mortality rates. Methods In this retrospective cohort analysis between 2014 and 2018, patients with non-traumatic, angiogram negative SAH (ANSAH) were identified. The admission mFI-5, mFI-11, CCI, and TMT were calculated for each patient. Primary outcomes were mortality rate, discharge location, and prolonged length of stay (PLOS; LOS >85th percentile). Multivariate logistic regression and receiver operating characteristic (ROC) curves were used to evaluate frailty as predictors of primary endpoints. Results We included 75 patients with a mean age of 55.4 ± 1.5 years. There were 4 patient deaths (5.3%), 53 patients (70.7%) discharged home, and 11 patients (14.7%) with PLOS. On ROC analysis, the mFI-5 had the highest discriminatory value for mortality (AUC = 0.97) while the mFI-11 was most discriminatory for discharge home (AUC = 0.85) and PLOS (AUC = 0.78). On multivariate analysis, the only independent predictor of mortality was the mFI-11 (OR = 0.46; 95%CI: 1.45–14.23; p = 0.009) while the mFI-5 was the best predictor of discharge home (OR = 0.21; 95% CI: 0.08–0.61; p = 0.004). On multivariate analysis, the only independent predictor of PLOS was the Hunt and Hess score (OR = 2.63; 95%CI: 1.38–5.00; p = 0.003). The CCI and TMT were inferior to either mFI for predicting primary endpoints. Conclusions Increasing frailty is associated with poorer outcomes and higher mortality following ANSAH. The mFI-5 and mFI-11 were found to be superior predictors of discharge home and mortality rate. While larger prospective study is needed, frailty, as measured by mFI-11 and -5, should be considered when evaluating ANSAH prognosis.