Continuous EEG Monitoring Practice Variation in TBI: Early Findings in the ELECTRO-BOOST Cohort
Kaitlyn Piotrowski1, Andrew Webb1, Benjamin MacDonald1, Eric Rosenthal1, Emily Gilmore2, Puneet Uppal2, Robert Silbergleit3, Ramon Diaz-Arrastia4, Jennifer Kim2, Sharon Yeatts5, Kan Ding6
1Massachusetts General Hospital, 2Yale University School of Medicine, 3University of Michigan, 4University of Pennsylvania, 5Medical University of South Carolina, 6UT Southwestern Medical Center
Objective:
Assess potential practice-pattern variation and referral bias regarding initiation of continuous EEG (cEEG) monitoring in the ELECTRO-BOOST study.
Background:
ELECTRO-BOOST, an ongoing ancillary study of BOOST-3 (Brain Oxygenation Optimization in Severe TBI), aims to assess associations of seizures and high-frequency EEG patterns on brain oxygenation, intracranial pressure, treatment, and outcome. Enrolled patients undergoing cEEG may differ from those not enrolled, and institutional or regional indications for cEEG may present variability, which can impact our primary analyses. To begin addressing these potential limitations, we explored site-specific differences in baseline characteristics, EEG monitoring type, and duration.
Design/Methods:
Variables collected from case report forms for 179 BOOST-3 participants at 12 ELECTRO-BOOST sites were analyzed. Associations between demographic characteristics, hospital, US region, baseline GCS, EEG type (none, routine, or continuous), cEEG duration, and invasive intracranial monitoring duration were assessed using a combination of statistical tests.
Results:
Participants undergoing cEEG monitoring (n=123), routine EEG (n=10), and no EEG (n=46) had a baseline GCS of 6 (IQR 4-7), 6 (IQR 3-6), and 6 (IQR 5-7), respectively. Those receiving any EEG monitoring had lower baseline GCS (p=0.03). Average cEEG duration across sites was 53.3 hours (95% CI:43.8-62.8) and varied significantly by hospital (p<0.001) and region (p=0.006). EEG monitoring type (p<0.001), race (p<0.001), and ethnicity (p<0.001) differed across hospitals, but sex and age did not. cEEG duration and EEG type did not differ based on demographics. Hospital site was significantly associated with cEEG duration (p<0.001) after adjustment for demographics and injury severity. Invasive intracranial monitoring duration differed based on EEG type (p=0.03).
Conclusions:
Preliminary review of patient characteristics confirm practice-pattern variation of cEEG monitoring in TBI even after adjusting for baseline demographics and injury severity. Next steps include exploring whether cEEG monitoring introduces additional practice-pattern variation related to medication use (i.e., seizure prophylaxis, sedation, and hyperosmolar therapy) that could confound our results.