Non-Hospitalized Patients with Mild Traumatic Brain Injury: The Forgotten Minority.

Non-hospitalized mild traumatic brain injury (mTBI) patients comprise a substantial part of the trauma population. For these patients, guidelines recommend specialized follow-up only in the case of persistent complaints or problems in returning to previous activities. This study describes injury and outcome characteristics of non-hospitalized mTBI patients, and the possibility of predicting which of the non-hospitalized patients will return to the outpatient neurology clinic. Data from all non-hospitalized mTBI patients (Glasgow Coma Scale [GCS] score 13-15, n = 462) from a prospective follow-up study on mTBI (UPFRONT-study) conducted in three level 1 trauma centers were analyzed. At 2 weeks, and 3 and 6 months after injury, patients completed questionnaires on post-traumatic complaints, depression, anxiety, outpatient follow-up, and resumption of activities. Most patients were male (57%), with a mean age of 40 years (range 16-91 years). Injuries were most often caused by traffic accidents (32%) or falls (39%). Six months after injury, 36% showed incomplete recovery as defined by the Glasgow Outcome Scale - Extended (GOS-E). Twenty-five percent of the non-hospitalized patients returned to the outpatient neurology clinic within 6 months after injury, of which one third had not completely resumed pre-injury activities. Regression analyses showed an increased risk for outpatient follow-up for patients scoring above the cutoff value for anxiety (odds ratio [OR] = 3.0), depression (OR = 3.5), or both (OR = 3.7) 2 weeks after injury. Our findings underline that clinicians and researchers should be aware of recovery for all mTBI patients, preventing their transition into a forgotten minority.