title: Trauma center-related biases in injury research.
abstract: OBJECTIVE
  Most studies from trauma centers analyze and present combined data on patients from their surrounding communities and patients referred for specialized services from service areas of other hospitals. Information is needed about the effect of combining data from the two groups on conclusions about injury in the community.
  
  
  METHODS
  All injured patients seen in a trauma center emergency department of 30% of days over one year were studied concerning referral status, age, sex, type of activity when injured, injury type and severity, hospitalization, and prior medical history.
  
  
  RESULTS
  Combining data for both groups suggested an older, more medically impaired population, with more severe injuries, more frequent hospitalization, more serious head and spine injuries, fewer extremity fractures, and fewer household-related and more transportation-related injuries than were actually occurring in the community.
  
  
  CONCLUSIONS
  Data from local and out-of-area referred patients at trauma centers should be analyzed and presented separately in studies from this source if an accurate representation is to be provided of the role of injury in the population at large of the community.
authors.affiliation: Department of Medicine, University of Vermont, Burlington 05405, USA.
authors.forename: J A
authors.initials: JA
authors.lastname: Waller
authors.forename: J M
authors.initials: JM
authors.lastname: Skelly
authors.forename: J H
authors.initials: JH
authors.lastname: Davis
mesh_terms: D015998:Abbreviated Injury Scale; D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D002648:Child; D005260:Female; D006302:Health Services Research / Q000379:methods*; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D015601:Injury Severity Score; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance; D012017:Referral and Consultation; D012042:Registries; D015983:Selection Bias; D014193:Trauma Centers / Q000706:statistics & numerical data*; D014707:Vermont / Q000453:epidemiology; D014947:Wounds and Injuries / Q000453:epidemiology*