A case-control study of driving-while-impaired offenders.

A case control approach was used to identify variables associated with driving while impaired (DWI). Data utilized for this study were obtained from interviews with individuals in a representative sample of 9943 Canadians. Individuals convicted for DWI were matched with control subjects (i.e. no DWI convictions) by gender, age, province of residence, education, income, and recent drinking behaviour. During the matching process, 39 current abstainers were found among the DWI offenders and were treated as a separate group for statistical purposes. Three groups were compared: 78 DWI cases, 78 matched controls, and 39 DWI current abstainers. Statistical analyses were used to detect significant differences among these three groups for 81 variables within the following categories: (a) attitudes, knowledge and behaviour related to drinking and driving; (b) driving behaviour; (c) drinking behaviour and drug use; (d) social issues; and (e) attitudes towards different policy approaches to reducing drinking and driving. DWI cases were significantly different from control subjects for only 10 variables. A high proportion of differences found between these two groups related to attitudes regarding drinking and driving behaviour. For example, DWI cases were more likely than controls to believe that some people drive better after drinking, that it takes more alcohol to be legally impaired, and that there is an excuse for DWI. DWI cases were more likely to drink due to sadness or loneliness, and reported higher cannabis use over previous years. Little evidence was found to support the hypothesis that DWI offenders are less likely to perceive deterrents to DWI. However, evidence does support the notion that many DWI offenders do not believe that they have a drinking problem. Implications of the findings are discussed.