Infrequent emergency department diagnosis and outpatient follow-up of mild traumatic brain injury after closed head injury: age and rurality patterns.

Mild traumatic brain injury (mTBI) is commonly encountered in the emergency department (ED), but there is wide variation in diagnosis, specialist referral, and follow-up. Our goal was to measure how frequently ED clinicians diagnosed mTBI during head injury evaluation at ED discharge and compare this to 1) mTBI diagnosis at outpatient follow-up and 2) mTBI diagnosis based on consensus diagnostic criteria via retrospectively reviewed clinical signs & symptoms. We further sought to assess how these frequencies vary with age and rurality. We performed a retrospective cohort study of adults treated and discharged from the ED with a diagnosis of closed head injury or mTBI for three months in one health system through electronic medical record data abstraction. We compared clinician diagnosis to 2023 American College of Rehabilitation Medicine (ACRM) consensus diagnostic criteria for mTBI and suspected mTBI. 314 patients were included and were predominantly urban (76%), age 65 years or older (42%) and female (62%). Forty patients (13%) had an ED diagnosis of mTBI, and 27 (9%) had suspected mTBI. ACRM-defined mTBI or suspected mTBI comprised 129 patients (41%), compared to 67 (21%) of clinician-documented mTBI or suspected mTBI. Eighty-four patients (27%) had a follow-up visit; 23 (8%) received mTBI diagnosis at follow-up. Young and urban adults were most frequently diagnosed with mTBI while rural and older adults were least frequently diagnosed. In conclusion, less than half of patients likely to have mTBI based on consensus criteria were diagnosed with mTBI at ED discharge, suggesting opportunities for improvement in ED management.