Alcohol use at time of injury and survival following traumatic brain injury: results from the National Trauma Data Bank.
OBJECTIVE
Premised on biological evidence from animal research, recent clinical studies have, for the most part, concluded that elevated blood alcohol concentration levels are independently associated with higher survival or decreased mortality in patients with moderate to severe traumatic brain injury (TBI). This study aims to provide some counterevidence to this claim and to further future investigations.


METHODS
Incident data were drawn from the largest U.S. trauma registry, the National Trauma Data Bank, for emergency department admission years 2002-2006. TBI was identified according to the National Trauma Data Bank's definition using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM), codes. To eliminate confounding, the exact matching method was used to match alcohol-positive with alcohol-negative incidents on sex, age, race/ethnicity, and facility. Logistic regression compared in-hospital mortality between 44,043 alcohol-positive and 59,817 matched alcohol-negative TBI incidents, with and without causes and intents of TBI and Injury Severity Score as covariates. A sensitivity analysis was performed within a subsample of isolated moderate to severe TBI incidents.


RESULTS
Alcohol use at the time of injury was found to be significantly associated with an increased risk for TBI. Including varied causes and intents of TBI and Injury Severity Score as potential confounders in the regression model explained away the statistical significance of the seemingly protective effect of alcohol against TBI mortality for all TBIs and for isolated moderate to severe TBIs.


CONCLUSIONS
The null finding shows that the purported reduction in TBI mortality attributed to positive blood alcohol likely is attributable to residual confounding. Accordingly, the risk of TBI associated with alcohol use should not be overlooked.
Alcohol Epidemiologic Data System, CSR, Incorporated, Arlington, VA, USA. cchen@csrincorporated.com
Chiung M
CM
Chen
Hsiao-Ye
HY
Yi
Young-Hee
YH
Yoon
Chuanhui
C
Dong
D000293:Adolescent; D000328:Adult; D000368:Aged; D000428:Alcohol Drinking / Q000009:adverse effects* / Q000453:epidemiology; D001930:Brain Injuries / Q000097:blood* / Q000453:epidemiology / Q000401:mortality* / Q000503:physiopathology; D015331:Cohort Studies; D015986:Confounding Factors, Epidemiologic; D004636:Emergency Service, Hospital; D000431:Ethanol / Q000097:blood*; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D015994:Incidence; D038801:International Classification of Diseases; D008297:Male; D016555:Matched-Pair Analysis; D008875:Middle Aged; D012042:Registries; D012306:Risk; D012720:Severity of Illness Index; D014481:United States / Q000453:epidemiology; D055815:Young Adult
D000431:Ethanol