Knowledge about the causes and time of injury for traumatic brain injury (TBI) is important for the development of efficient prevention policies.
We aimed to study time of injury and relation to alcohol intoxication for moderate to severe TBI in a level 1 trauma center in Norway.
From October 2004 to September 2014, 493 consecutive moderate (Glasgow Coma Scale score [GCS] 9-13) and severe TBI (GCS score 3-8) patients (=16 years) were prospectively included in the Trondheim TBI Study (222 moderate and 270 severe TBI patients).
Mean age was 47 years (SD 21). Positive blood alcohol concentration (BAC) was found in 29% and median BAC was 41.5 mmol/l (IQR 28.7 to 54.3), equal to 1.91‰. Admissions were more frequent on Saturdays (RR 2.67, 95% CI 1.87 to 3.80) and Sundays (RR 2.10, 95% CI 1.45 to 3.03) compared to Mondays, and positive BAC was more common on weekends than weekdays (43% versus 16%). Furthermore, admissions were more frequent in June (RR 2.26, 95% CI 1.44 to 3.55), July (RR 2.07, 95% CI 1.31 to 3.28) and December (RR 2.07, 95% CI 1.31 to 3.28) compared to January. The number of patients with positive BAC was highest in December (RR 5.75, 95% CI 1.99 to 16.63) and 70% of these were caused by falls.
Our findings demonstrate that moderate to severe TBI admissions display a clear weekly and seasonal variation, and that alcohol is an important modifiable risk factor for moderate to severe TBI.; Abbreviations: BAC = Blood alcohol concentration, GCS = Glasgow coma scale, TBI = Traumatic brain injury.