title: Predictive effect of out-of-hospital time in outcomes of severely injured young adult and elderly patients.
abstract: BACKGROUND
  The importance of accessing care within the first hour after injury has been a fundamental tenet of trauma system planning for 30 years. However, the scientific basis for this belief either has been missing or largely derived from case series from trauma centers. This study sought to determine the correlation between prehospital times and outcomes among severely injured elderly patients.
  
  
  METHODS
  This is a cross-sectional, observational study. All adults (> or = 18 years of age) with acute trauma as defined by The International Classification of Diseases Ninth Edition, Clinical Modification diagnostic codes and E-codes were included. Poisonings, single system burns, and late effects of injury were excluded. Chi-square and Student's t-test were used for significance testing. To assess the predictive effects of prehospital time and outcomes, three independent logistic regression models were constructed for both young and elderly groups, with hospital length of stay, mortality, and complications as individual dependent variables. Statistical significance was set at the 0.05 level.
  
  
  RESULTS
  Of 41,041 cases, 37,276 were > or = 18 years of age. Of the 1,866 with an Injury Severity Score (ISS) > 15, 1,205 were young and 661 elderly. Logistic regression results showed that prehospital time correlated significantly with hospital length of stay (p = 0.001) and complications (p = 0.016), but not with mortality (p = 0.264) among young patients, whereas in the elderly group pre-hospital time had no significant predictive effect for length of stay, complications, or mortality (p = 0.512, p = 0.512, and p = 0.954 respectively).
  
  
  CONCLUSIONS
  This population-based study has demonstrated that prehospital time correlates with length of stay and complications in young patients. In elderly patients, prehospital time failed to show correlation with any outcomes measured.
authors.affiliation: Division of Trauma, Burns and Surgical Critical Care, Department of Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA. aabaez@partners.org
authors.forename: Amado Alejandro
authors.initials: AA
authors.lastname: Báez
authors.forename: Peter L
authors.initials: PL
authors.lastname: Lane
authors.forename: Barbara
authors.initials: B
authors.lastname: Sorondo
authors.forename: Ediza M
authors.initials: EM
authors.lastname: Giráldez
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D004632:Emergency Medical Services; D006801:Humans; D015601:Injury Severity Score; D007902:Length of Stay; D016015:Logistic Models; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D010414:Pennsylvania; D013997:Time Factors; D014947:Wounds and Injuries / Q000145:classification / Q000628:therapy*