title: High re-arrest rates among drug-impaired drivers despite zero-tolerance legislation.
abstract: BACKGROUND
  A zero-tolerance law for driving under the influence of drugs (DUID) in Sweden led to a 10-fold increase in the number of cases submitted by the police for toxicological analysis. The statutory blood-alcohol concentration (BAC) limit for driving is 0.2 mg/g ( approximately 0.02 g%).
  
  
  METHODS
  An in-house database (TOXBASE) was used to investigate re-arrests for impaired driving over 4 years (2001-2004), which comprised 36,799 cases. The age, gender, re-arrest rate of the offenders and the concentrations of ethanol and amphetamine in blood samples were evaluated.
  
  
  RESULTS
  We found that 44% of individuals (N=16,277) re-offended 3.2 times on average (range 1-23 arrests). Between 85 and 89% of first-time offenders were men and there was also a male dominance among the recidivists (88-93%). The mean age of drunken drivers was approximately 40 years compared with approximately 35 years for driving under the influence of amphetamine, which was the drug identified in 50-60% of DUID cases, either alone or together with other licit or illicit drugs. The median BAC was 1.5mg/g ( approximately 0.15 g%), which suggests a dominance of heavy drinkers. The median BAC was even higher in recidivists (1.6-1.7 mg/g). The median concentration of amphetamine in blood was 1.0 mg/L in recidivists compared with 0.5mg/L in the first-time offenders. About 14% of drunken drivers re-offended 1-10 times compared with 68% of DUID suspects, who were re-arrested 1-23 times. People with only a scheduled prescription drug in blood were re-arrested much less frequently ( approximately 17%) compared with those taking illicit drugs (68%).
  
  
  CONCLUSIONS
  The appreciable increase in number of arrests for DUID after a zero-tolerance law might reflect a heightened enthusiasm by the police authorities armed with knowledge that a prosecution is easier to obtain. Zero-tolerance laws do not deter people from impaired driving judging by the high re-arrest rates. During the sentencing of hardcore offenders, the courts should give more consideration to the underlying substance abuse problem.
authors.affiliation: Department of Forensic Genetics and Forensic Toxicology, National Board of Forensic Medicine, Artillerigatan 12, SE-581 33 Linköping, Sweden.
authors.forename: Anita
authors.initials: A
authors.lastname: Holmgren
authors.forename: Per
authors.initials: P
authors.lastname: Holmgren
authors.forename: Fredrik C
authors.initials: FC
authors.lastname: Kugelberg
authors.forename: A Wayne
authors.initials: AW
authors.lastname: Jones
authors.forename: Johan
authors.initials: J
authors.lastname: Ahlner
mesh_terms: D000328:Adult; D000428:Alcohol Drinking; D000435:Alcoholic Intoxication / Q000150:complications*; D001334:Automobile Driving / Q000331:legislation & jurisprudence*; D019992:Databases as Topic; D005260:Female; D006801:Humans; D013287:Illicit Drugs; D008297:Male; D011329:Prisoners; D011330:Prisons; D012307:Risk Factors; D013548:Sweden
chemical_list: D013287:Illicit Drugs