Frailty is a risk factor for intracranial abscess and is associated with longer length of stay: a retrospective single institution case-control study.

Abstract

Background: Intracranial abscess (IA) causes significant morbidity and mortality. The impact of baseline frailty status on post-operative outcomes of IA patients remains largely unknown. The present study evaluated if frailty status can be used to prognosticate outcomes in IA patients.

Methods: We retrospectively reviewed all IA patients undergoing craniotomy at our institution from 2011 to 2018 (N.=18). These IA patients were age and gender matched with patients undergoing craniotomy for intracranial tumor (IT), an internal control for comparison. Demographic and clinical data were collected to measure frailty, using the modified frailty index-11 (mFI-11) and pre-operative American Society of Anesthesiologists Physical Status Classification System (ASA). Post-operative complications were measured by the Clavien-Dindo Grade (CDG).

Results: No significant difference in mFI-11 or ASA score was observed between the IA and IT groups (P=0.058 and P=0.131, respectively). IA patients had significantly higher CDG as compared with the control IT patients (P<0.001). There was a trend towards increasing LOS in the IA group as compared to the IT group (P=0.053). Increasing mFI and ASA were significant predictors of LOS by multiple linear regression in the IA group (P=0.006 and P=0.001, respectively), but not in the control IT group. Neither mFI-11 nor ASA were found to be predictors for CDG in either group. Within this case-control group of patients, we found an increase for odds of having IA with increasing mFI (OR=1.838, 95% CI: 1.016-3.362, P=0.044).

Conclusions: Frail IA patients tend to have more severe postoperative complications. The mFI-11 seems to predict increased resource utilization in the form of LOS. This study provides the initial retrospective data of another neurosurgical pathology where frailty leads to significantly worse outcomes. We also found that mFI may serve as a potential risk factor for severe disease.