Drug and Driving: A Compendium of Research Studies

Annotated Sources (cont'd)

Denmark

35. Behrensdorff, I., and Steentoft, A. (2003)

Medicinal and illegal drugs among Danish car drivers. Accident Analysis and Prevention, 35: 851-860.

Overview

Roadside survey of drug use among drivers in Denmark

Type of study, population(s) and proportion tested

1000 car or small van drivers stopped randomly by police in a rural area of Denmark

Overall time period not mentioned but time of day for collection of samples was broken down into three sessions
of 08:00-18:00, 18:00-24:00, 24:00-8:00

Drugs in question
  • Benzodiazepines
  • Cocaine
  • Cannabis
  • Opiates
  • Amphetamines
Method of testing and medium used

Saliva samples

Other dependent variables

Participants asked to complete and return, via mail, a questionnaire about their use of medicinal and illegal drugs prior to car driving and their opinion in police drug controls

Findings (including statistical methods)

Of 896 saliva samples, 2% positive for benzodiazepines or illegal drugs

Of that, 1.3% positive for illegal drugs, the majority concerned cannabis

In 0.7%, one or more benzodiazepines were detected

66% of questionnaires returned

6% stated using a medicinal or illegal drug within 24 hours of being stopped

3% indicated yes to driving despite the suspicion of being under the influence

4% admitted driving a few hours after have both illegal drugs and alcohol

9% admitted to driving a few hours after having a hazardous medicinal drug and alcohol

25% admitted driving when they suspected they were over the legal limit

36. Bernhoft, I.M. and Steentoft, A. (2002)

Licit and Illicit drugs among Danish car drivers. In: D.R. Mayhew and C. Dussault (Eds) Proceedings of the 16th International Conference on Alcohol, Drugs and Traffic Safety. Quebec: Société de l’Assurance Automobile du Québec.

Overview

Roadside survey of drivers on the road not suspected of drug use

Type of study, population(s) and proportion tested

Random roadside survey -- police stopped at random while on patrol

961 of 980 (98%) of drivers provided samples for analysis

896 of samples were adequate for testing

636 (66%) drivers returned a questionnaire

Drugs examined (threshold values for detection)
  • Cocaine
  • Cannabinoids
  • Alcohol
  • Opiates
  • Amphetamines
Method of testing and medium used

Saliva -- RapiScan replaced by Cozart (neither completely adequate)
Screening confirmed by GC/MS

Other dependent variables

Self-reported driving under influence of drugs

Findings (including statistical methods)

Screening: 7.1% positive for drugs

Confirmatory: 2.0%:

  • 0.7% benzodiazepines
  • 1.3% amphetamines, cannabis, cocaine, opiates (0.8% cannabis)

6.0% admit to driving under influence of drugs past 24 hours

  • 3.0% potentially hazardous prescriptions
  • 2.8% other drugs not a hazard to road safety
  • 0.2% illicit drugs

2.8% admit driving despite suspicion they were under influence

4% admit driving after using an illicit drug plus alcohol

8.5% admit driving after using a potentially hazardous drug plus alcohol

24.5% admit driving with BAC >.05%

Comments

"Random" stopping of drivers by police is questionable

Discrepancy between screening results and GC/MS results is troubling

37. Bernhoft, I. M., Steenhoft, A., Johansen, S., and Klitgaard, N. A. (2004)

A qualitative analysis of drugs as a contributing factor to accidents in Denmark.  In J. Oliver, P. Williams and A. Clayton (Eds), Proceedings of the 17th International Conference on Alcohol, Drugs and Traffic Safety (CD). Glasgow: Scottish Executive.

Overview

Emergency room study of injured drivers

Type of study, population(s) and proportion tested

Injured drivers of cars, motorcycles, and mopeds brought to or visited emergency rooms in two selected hospitals in Denmark

Time period not given (mentioned a period of year to obtain this data)

Drugs examined
  • Benzodiazepines
  • Opiates (including morphine and codeine)
  • Amphetamines
  • Methamphetamines (including ecstasy)
  • Cannabinoids
  • Cocaine
Method of testing and medium used

Injured drivers in emergency rooms were asked to answer questions, and give a saliva or blood sample (or both)

Those testing positive were asked to give an interview about their accident and drug use, physical and mental condition at time of accident, and knowledge of the influence of drugs on driving abilities

Other dependent variables
Findings (including statistical methods)

Of the 300 cases thus far, 21 confirmed positive (7%)

In this 7%, cannabinoids and benzodiazepines most common (67%)

15 of the 21 patients (71%) found positive for one drug (5 of these were also impaired by alcohol) and 6 (29%) were positive for two (3 of these also impaired by alcohol) – (38% total combined with alcohol)

Researchers characterized two common types of drug-impaired drivers:

Young men who take illegal drugs (amphetamines and cannabinoids) either during evenings or weekends, generally do not mix with alcohol, and who do not think it is dangerous to drive

Middle aged men and women who stopped working because of their dependency, do not refrain from mixing drugs with alcohol, and do not feel that it is dangerous to drive

Comments

Study is ongoing

38. Johansen, S. S. (2002)

Ecstasy and designer amphetamines: Findings in drivers and post-mortem cases in Denmark. In D. R. Mayhew and C. Dussault (Eds.) Proceedings of the 16th International Conference on Alcohol, Drugs and Traffic Safety. Quebec: Société de l’Assurance Automobile du Québec.

Overview

Historical overview of presence of amphetamine and ecstasy in Denmark drivers

Type of study, population(s) and proportion tested

Traffic cases requested by police for analysis of drugs from 1995 to 2001

Between 201-235 cases annually

Drugs examined (threshold values for detection)
  • Common drugs with emphasis on amphetamines and designer amphetamines (ecstasy)
  • Narcotics
  • Alcohol
Method of testing and medium used

Blood and urine samples

Other dependent variables
Findings (including statistical methods)

Prevalence of amphetamines from 1995 to 1998 increased from 10 to 15%

This dropped to 10% in 2000, followed by an increase to 18% in 2001

This increase coincides with an increase in designer amphetamine prevalence

Prevalence of designer amphetamines rose from 1% in 1997 to 4% in 2000 (3% in 2001)

39. Steentoft, A., and Worm, K. (1996)

Drugs in Danish traffic cases where no alcohol was found present. Journal of Traffic Medicine 24(3-4): 73-76.

Overview

Study of suspected impaired drivers in Denmark

Type of study, population(s) and proportion tested

294 drivers suspected of driving under the influence of alcohol and/or drugs in Denmark

Blood samples reveal no alcohol (<.10 mg/g)

Time period of half a year in 1991

Drugs examined
  • Benzodiazepines (.2 μmol/kg)
  • Morphine (.05 μmol/kg)
  • Cocaine (.3 μmol/kg)
  • Amphetamine (.2 μmol/kg)
Method of testing and medium used

Blood sample data obtained from Institute of Forensic Medicine in Copenhagen

Other dependent variables

None

Findings (including statistical methods)

Drugs detected in 27% of the 294 cases with 51% of these showing only one drug (mainly benzodiazepines)

23% of the 294 cases were positive for benzodiazepines

7% positive for morphine (all males)

5% positive for amphetamine

47% of the drug positive cases were connected with a traffic accident

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