How Well Do EMS Providers Predict Intracranial Hemorrhage in Head-Injured Older Adults?

Objective: To evaluate the accuracy of emergency medical services (EMS) provider judgment for traumatic intracranial hemorrhage (tICH) in older patients following head trauma in the field. We also compared EMS provider judgment with other sets of field triage criteria. Methods: This was a prospective observational cohort study conducted with five EMS agencies and 11 hospitals in Northern California. Patients 55 years and older who experienced blunt head trauma were transported by EMS between August 1, 2015 and September 30, 2016, and received an initial cranial computed tomography (CT) imaging, were eligible. EMS providers were asked, "What is your suspicion for the patient having intracranial hemorrhage (bleeding in the brain)?" Responses were recorded as ordinal categories (<1%, 1-5%, >5-10%, >10-50%, or >50%) and the incidences of tICH were recorded for each category. The accuracy of EMS provider judgment was compared to other sets of triage criteria, including current field triage criteria, current field triage criteria plus multivariate logistical regression risk factors, and actual transport. Results: Among the 673 patients enrolled, 319 (47.0%) were male and the median age was 75 years (interquartile range 64-85). Seventy-six (11.3%) patients had tICH on initial cranial CT imaging. The increase in EMS provider judgment correlated with an increase in the incidence of tICH. EMS provider judgment had a sensitivity of 77.6% (95% CI 67.1-85.5%) and a specificity of 41.5% (37.7-45.5%) when using a threshold of 1% or higher suspicion for tICH. Current field triage criteria (Steps 1-3) was poorly sensitive (26.3%, 95% CI 17.7-37.2%) in identifying tICH and current field trial criteria plus multivariate logistical regression risk factors was sensitive (97.4%, 95% CI 90.9-99.3%) but poorly specific (12.9%, 95% CI 10.4-15.8%). Actual transport was comparable to EMS provider judgment (sensitivity 71.1%, 95% CI 60.0-80.0%; specificity 35.3%, 95% CI 31.6-38.3%). Conclusions: As EMS provider judgment for tICH increased, the incidence for tICH also increased. EMS provider judgment, using a threshold of 1% or higher suspicion for tICH, was more accurate than current field triage criteria, with and without additional risk factors included.