To use an independent cohort to validate the 2HELPS2B score and develop a practical guide for its use.

Seizure risk stratification is needed to boost inpatient seizure detection and to improve continuous electroencephalogram (cEEG) cost-effectiveness. 2HELPS2B can address this need but requires validation.

This multicenter retrospective medical record review analyzed clinical and EEG data from adult patients with an EEG duration of 12 hours or longer at 6 centers from January 2012 to January 2019. 2HELPS2B was evaluated with the validation cohort using the mean calibration error (CAL). A Kaplan-Meier analysis was used to determine the duration of EEG monitoring to achieve a seizure risk of less than 5%based on the 2HELPS2B score calculated on first- hour EEG.

The study included 2111 participants and the primary outcome was met with a validation cohort CAL error of 4.0% compared with a CAL of 2.7%in the foundational cohort (P = .13). For the 2HELPS2B score calculated on only the first hour of EEG in those without seizures the patients were stratified into low- (2HELPS2B = 0; <5%), medium- (2HELPS2B = 1; 12%), and high-risk (2HELPS2B,2; risk of seizures, >25%) groups. Each had minimum recommended duration of EEG monitoring to achieve at least a less than 5%risk of seizures, a 2HELPS2B score of 0 at 1-hour screening EEG, a 2HELPS2B score of 1 at 12 hours, and a 2HELPS2B score of 2 or greater at 24 hours.

In this study, 2HELPS2B was validated as a clinical tool to aid in seizure detection, clinical communication, and cEEG use. In patients without prior clinical seizures, a screening 1-hour EEG that showed no epileptiform findings was an adequate screen. In patients with any highly epileptiform EEG patterns during the first hour of EEG (ie, a 2HELPS2B score of2), at least 24 hours of recording is recommended.