title: Effects of acute substance use and pre-injury substance abuse on traumatic brain injury severity in adults admitted to a trauma centre.
abstract: BACKGROUND
  The aims of this study were to describe the occurrence of substance use at the time of injury and pre-injury substance abuse in patients with moderate-to-severe traumatic brain injury (TBI). Effects of acute substance use and pre-injury substance abuse on TBI severity were also investigated.
  
  
  METHODS
  A prospective study of 111 patients, aged 16-55 years, injured from May 2005 to May 2007 and hospitalised at the Trauma Referral Centre in Eastern Norway with acute TBI (Glasgow Coma Scale 3-12). Based on structural brain damages shown on a computed tomography (CT) scan, TBI severity was defined by modified Marshall classification as less severe (score <3) and more severe (score >/=3). Clinical definition of substance use (alcohol and/or other psychoactive substances) was applied when hospital admission records reflected blood alcohol levels or a positive drug screen, or when a physician verified influence by examining the patient. Pre-injury substance abuse (alcohol and drug problems) was screened by using the CAGE questionnaire.
  
  
  RESULTS
  Forty-seven percent of patients were positive for substance use on admission to hospital. Significant pre-injury substance abuse was reported by 26% of patients. Substance use at the time of injury was more frequent in the less severe group (p = 0.01). The frequency of pre-injury substance abuse was higher in the more severe group (30% vs. 23%). In a logistic regression model, acute substance use at time of injury tended to decrease the probability of more severe intracranial injury, but the effect was not statistically significant after adjusting for age, gender, education, cause of injury and substance abuse, OR = 0.39; 95% CI 0.11-1.35, p = 0.14. Patients with positive screens for pre-injury substance abuse (CAGE >/=2) were more likely to have more severe TBI in the adjusted regression analyses, OR = 4.05; 95% CI 1.10-15.64, p = 0.04.
  
  
  CONCLUSIONS
  Acute substance use was more frequent in patients with less severe TBI caused by low-energy events such as falls, violence and sport accidents. Pre-injury substance abuse increased the probability of more severe TBI caused by high-energy trauma such as motor vehicle accidents and falls from higher levels. Preventive efforts to reduce substance consumption and abuse in at-risk populations are needed.
authors.affiliation: Department of Physical Medicine and Rehabilitation, Oslo University Hospital, Ulleval, Norway. nada.andelic@ulleval.no.
authors.forename: Nada
authors.initials: N
authors.lastname: Andelic
authors.forename: Tone
authors.initials: T
authors.lastname: Jerstad
authors.forename: Solrun
authors.initials: S
authors.lastname: Sigurdardottir
authors.forename: Anne-Kristine
authors.initials: AK
authors.lastname: Schanke
authors.forename: Leiv
authors.initials: L
authors.lastname: Sandvik
authors.forename: Cecilie
authors.initials: C
authors.lastname: Roe