Introduction: A simple tool that could support individualized approach to anticonvulsant prophylaxis during hospital admission in patients with subarachnoid hemorrhage (SAH) would have clinical utility. This study was aimed at developing such a tool.
Methods: We developed a risk score in 1500 patients from the SAH outcomes project of Columbia University, and validated it in 825 patients derived from the Washington University Database of SAH including patients from the CONSCIOUS 1 trial. Candidate predictors were identified by systematic review of literature and included in a backward stepwise logistic regression model with in-hospital seizure as dependent variable. The performance of the risk score was assessed using the area under the receiver operator characteristics curve (AUC) and calibration plots.
Results: The SAFARI score (Seizure AFter aneurysmal subarachnoid hemorrhage RIsk score) based on four items including age > 60 years, seizure occurrence prior to hospitalization, aneurysm location and hydrocephalus had AUC = 0.77 (95% Confidence Intervals [CI]: 0.73 – 0.82) in the development cohort. In the validation cohort, the AUC was 0.65 (95% CI: 0.56 – 0.73). Calibration plots demonstrated excellent agreement between observed and predicted risk of in-hospital seizure.
Conclusions: We have developed a simple tool for predicting the likelihood of seizure during hospitalization for SAH. The SAFARI score could be helpful to guide treatment choices regarding the use of anticonvulsants during admission, and to optimize patient enrolment for clinical trials evaluating seizure management after SAH, among other benefits.