title: Driving decisions when leaving electronic music dance events: driver, passenger, and group effects.
abstract: OBJECTIVE
  The goal of this article was to identify characteristics of drivers and passengers that predicted peer groups whose drivers exit dance clubs with alcohol levels indicative of impairment (blood alcohol content [BAC] ≥ 0.05 g/dL).
  
  
  METHODS
  We used the portal survey methodology to randomly sample groups of electronic music dance event (EMDE) patrons as they entered and exited a club. From May through November 2010, data were collected from 38 EMDEs hosted by 8 clubs in the San Francisco Bay area. Data included in these analyses are results from breath samples for measuring BAC and self-report data on demographics, recent drinking history drinking, drinking intentions, travel to and from the clubs, and the familiarity/experience with other group members. These data were collected from a subset of 175 drivers and 272 passengers.
  
  
  RESULTS
  Although drivers drank less than passengers, one driver in 5 groups had a BAC indicative of elevated crash risk (BAC ≥ 0.05 g/dL). Groups of drivers and/or passengers with a recent history of binge drinking were more likely to have drivers with BACs ≥ 0.05 g/dL. One unanticipated finding was that drivers who knew more group members relatively well were more likely to exit the club with a BAC ≥ 0.05 g/dL. Additionally, we found that groups with all female passengers were at greater risk for having a driver whose BAC was ≥ 0.05 g/dL.
  
  
  CONCLUSIONS
  Some group characteristics predicted drivers who exit clubs with BACs ≥ 0.05 g/dL. One intervention strategy to promote safety might be to encourage group members to reconsider who is sober enough to drive away from the club; for some groups, a change of drivers would be a safer choice, because a passenger may have a relatively safe BAC. Groups of females appear to have a particularly elevated risk of having a driver whose BAC exceeds 0.05 g/dL, and new intervention efforts should be particularly directed to these at-risk groups.
authors.affiliation: Pacific Institute for Research and Evaluation, Calverton, Maryland 20705, USA. mjohnson@pire.org
authors.forename: Mark B
authors.initials: MB
authors.lastname: Johnson
authors.forename: Robert B
authors.initials: RB
authors.lastname: Voas
authors.forename: Brenda A
authors.initials: BA
authors.lastname: Miller
mesh_terms: D000328:Adult; D000428:Alcohol Drinking / Q000453:epidemiology*; D001334:Automobile Driving / Q000523:psychology*; D003615:Dancing; D003657:Decision Making; D004581:Electronics; D000431:Ethanol / Q000097:blood; D005260:Female; D006801:Humans; D008297:Male; D009146:Music; D010379:Peer Group; D018570:Risk Assessment; D012919:Social Behavior; D055815:Young Adult
chemical_list: D000431:Ethanol