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Drug and Driving: A Compendium of Research Studies
Annotated Sources (cont'd)
United Kingdom
57. Barbone, F., McMahon, A. D., Davey, P. G., Morris, A. D., Reid, I. C., McDevitt, D. G., and MacDonald, T. M. (1998). Association of road-traffic accidents with benzodiazepine use. Lancet 352: 1331-6.
Overview
Within-person case-crossover study of crashes among psychoactive drug users
Type of study, population(s) and proportion tested
All drivers 18 years or older who experienced a road-traffic accident between August 1, 1992 – June 30, 1995, which was attended by Tayside (UK) police
Residents in Tayside and had been registered with a Tayside general practitioner between January 1992 and January 1995
Had been using a psychoactive drug at some time during the study period
Drugs examined
Method of testing and medium used
Other dependent variables
Findings (including statistical methods)
Identified 1731 users of any study drug
Using logistic regression, the odds ratios for having a road-traffic accident on a day of drug use for different drugs were:
Risks associated with benzodiazepine use:
Was significant in drivers who failed a breath test for alcohol but was much stronger in those with a positive test (this difference in risk was significant)
Benzodiazepines with a long half-life were associated with an increased risk of accident
58. Buttress, S. C., Tunbridge, R. J., Oliver, J. S., Torrance, H., and Wylie, F. (2004). The incidence of drink and drug driving in the UK – A roadside survey in Glasgow. 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
Roadside survey as part of a larger case-control study
Type of study, population(s) and proportion tested
Non-accident involved drivers at sites within the area of the hospitals from which they obtained their accident-involved sample
Collected at same times of day as the people in the accident sample had their accidents
Time period from July 2003 to June 2004
Drugs examined (threshold values for detection)
Method of testing and medium used
Drivers stopped at random and asked to offer a sample of saliva and complete a questionnaire about items such as alcohol consumption, driving habits, use of drugs and medicines
Other dependent variables
None
Findings (including statistical methods)
As of March 2004, chemical analysis completed on 386 saliva samples
Eighteen drugs detected (incidence of 4.7%)
Much lower than the 22.9% found previously in their road fatality study
Ecstasy was most common, followed by cocaine and cannabis
However, only 65 of the 386 cases had been tested for cannabis so researchers suggest that cannabis is likely to be the most common once all analyses are complete
No questionnaires analyzed at this point
Comments
Study is ongoing
59. Sexton, B.F., Tunbridge, R.J., Board, A., Jackson, P.G., Wright, K., Stark, M.M., and Englehart, K. (2002) The Influence of Cannabis and Alcohol on Driving. TRL Report 543. Crowthorne, England: Transport Research Laboratory.
Overview
Study of the effects of cannabis in combination with alcohol
Type of study, population(s) and proportion tested
Male drivers
Simulator and laboratory tasks
Drugs examined (threshold values for detection)
Method of testing and medium used
Other dependent variables
Findings (including statistical methods)
Under the influence of cannabis subjects: reduced speed, increased headway, were aware of the effects, were less accurate in maintaining lane position, had poorer tracking, performed more poorly on sobriety tests
Subjects actively attempted to compensate for the effects
Alcohol and cannabis together produced an effect slightly greater than cannabis alone
60. Tunbridge, R. J., Keigan, M., and James, F. (2002). A comparison of the incidence of drugs in drink drivers and fatal road casualties. 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
Comparison of drug use trends in drinking drivers and fatal road users
Type of study, population(s) and proportion tested
Random selection of drinking driver cases from TRL for England and Wales (n=2000)
Fatal road casualties (n=1184)
Time period of 1997
Drugs examined
Method of testing and medium used
Blood sample information from Forensic Science Service
Other dependent variables
Sex, and age
Findings (including statistical methods)
