title: Alcohol use and drunk driving: the modifying effect of impulsivity.
abstract: OBJECTIVE
  The aim of this study was twofold: (a) to examine how an increase in the frequency of heavy drinking episodes affects the incidence of drunk driving and (b) to examine whether the effect of alcohol use on drunk driving is contingent on impulsivity.
  
  
  METHODS
  Two waves of the Young in Norway Longitudinal Study were applied (N = 2,603; response rate: 67%), when the respondents were on average 17 (1994) and 28 (2005) years of age. Measurements consisted of self-reported heavy episodic drinking, drunk driving, and impulsivity.
  
  
  RESULTS
  The first difference method was applied to estimate the association between heavy episodic drinking and drunk driving. This means that changes in the frequency of drunk driving were regressed on changes in the frequency of drinking. In this way, the effects of time-invariant confounders were eliminated. The results showed that every additional episode of heavy drinking was associated with a 2.6% increase in the frequency of drunk driving. The increase for males was significantly higher than among females. The analyses supported the hypothesis that impulsivity modifies the association between alcohol use and drunk driving.
  
  
  CONCLUSIONS
  The association between drinking and drunk driving is significantly stronger among those with a high score on impulsivity compared with those who have a low score.
authors.affiliation: Norwegian Institute for Alcohol and Drug Research (SIRUS), Oslo, Norway. ism@sirus.no
authors.forename: Inger Synnøve
authors.initials: IS
authors.lastname: Moan
authors.forename: Thor
authors.initials: T
authors.lastname: Norström
authors.forename: Elisabet E
authors.initials: EE
authors.lastname: Storvoll
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000428:Alcohol Drinking / Q000453:epidemiology*; D000435:Alcoholic Intoxication / Q000453:epidemiology*; D001334:Automobile Driving / Q000331:legislation & jurisprudence*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007175:Impulsive Behavior / Q000453:epidemiology*; D008137:Longitudinal Studies; D008297:Male; D009664:Norway / Q000453:epidemiology; D012737:Sex Factors