Frailty in aneurysmal subarachnoid hemorrhage: the risk analysis index

Few studies have evaluated frailty in the setting of aneurysmal subarachnoid hemorrhage (aSAH) using large-scale data. The risk analysis index (RAI) may be implemented at the bedside or assessed retrospectively, differentiating it from other indices used in administrative registry-based research.

Adult aSAH hospitalizations were identified in the National Inpatient Sample (NIS) from 2015 to 2019. Complex samples statistical methods were performed to evaluate the comparative effect size and discriminative ability of the RAI, the modified frailty index (mFI), and the Hospital Frailty Risk Score (HFRS). Poor functional outcome was determined by the NIS-SAH Outcome Measure (NIS-SOM), shown to have high concordance with modified Rankin Scale scores > 2.

42,300 aSAH hospitalizations were identified in the NIS during the study period. By both ordinal [adjusted odds ratio (aOR) 3.20, 95% confidence interval (CI) 3.05, 3.36, p < 0.001] and categorical stratification [frail aOR 3.59, 95% CI 3.39, 3.80, p < 0.001; severely frail aOR 6.67, 95% CI 5.78, 7.69, p < 0.001], the RAI achieved the largest effect sizes for NIS-SOM in comparison with the mFI and HFRS. Discrimination of the RAI for NIS-SOM in high-grade aSAH was significantly greater than that of the HFRS (c-statistic 0.651 vs. 0.615). The mFI demonstrated the lowest discrimination in both high-grade and normal-grade patients. A combined Hunt and Hess-RAI model (c-statistic 0.837, 95% CI 0.828, 0.845) for NIS-SOM achieved significantly greater discrimination than both the combined models for mFI and HFRS (p < 0.001).

The RAI was robustly associated with poor functional outcomes in aSAH independent of established risk factors.