Sheila MacDonald

Multicentre study of acute alcohol use and non-fatal injuries: data from the WHO collaborative study on alcohol and injuries

OBJECTIVES To study the risk of non-fatal injury at low levels and moderate levels of alcohol consumption as well as the differences in risk across modes of injury and differences among alcoholics. METHODS Data are from patients aged 18 years and older collected in 2001-02 by the WHO collaborative study on alcohol and injuries from 10 emergency departments around the world (n = 4320). We used a case-crossover method to compare the use of alcohol during the 6 hours prior to the injury with the use of alcohol during same day of the week in the previous week. FINDINGS The risk of injury increased with consumption of a single drink (odds ratio (OR) = 3.3; 95% confidence interval = 1.9-5.7), and there was a 10-fold increase for participants who had consumed six or more drinks during the previous 6 hours. Participants who had sustained intentional injuries were at a higher risk than participants who had sustained unintentional injuries. Patients who had no symptoms of alcohol dependence had a higher OR. CONCLUSION Since low levels of drinking were associated with an increased risk of sustaining a non-fatal injury, and patients who are not dependent on alcohol may be at higher risk of becoming injured, comprehensive strategies for reducing harm should be implemented for all drinkers seen in emergency departments.

Non-response bias in alcohol and drug population surveys.

INTRODUCTION AND AIMS This proposed study was to assess non-response bias in the 2004 Canadian Addictions Survey (CAS). DESIGN AND METHODS Two approaches were used to assess non-response bias in the CAS which had a response rate of only 47%. First, the CAS sample characteristics were compared with the 2002 Canadian Community Health Survey (CCHS, response rate 77%) and the 2001 Canada Census data. Second, characteristics of early and late respondents were compared. RESULTS People with lowest income and less than high-school education and those who never married were under-represented in the CAS compared with the Census, but similar to the CCHS. Substance use was more prevalent in the CAS than the CCHS sample, but most of the CAS and CCHS estimates did not exceed +/-3% points. Late respondents were also significantly more likely to be male, young adult, highly educated, used, have high income, live in different provinces and report substance use. Multivariate logistic regression found significant non-response bias for lifetime, past 12 months, chronic risky, acute risky and heavy monthly alcohol use, lifetime and past year cannabis use, lifetime hallucinogen use, any illicit drug uses of lifetime and past year. Adjustment for non-response bias substantially increased prevalence estimates. For example, the estimates for lifetime and past 12 month illicit drug use increased by 5.22% and 10.34%. DISCUSSION AND CONCLUSIONS It is concluded that non-response bias is a significant problem in substance use surveys with low response rates but that some adjustments can be made to compensate.

Driving Behavior Under the Influence of Cannabis or Cocaine

Objective. The purpose of this study is first to describe perceptions of driving under the influence of cannabis or cocaine among clients in treatment and, second, to assess whether these perceptions are related to the frequency of driving under the influence of cannabis or cocaine. Methods. A questionnaire was administered to clients in treatment for abuse of either cocaine or cannabis, many of whom also had a problem with alcohol; additional groups of clients consisted of those in smoking cessation and gambling programs (N = 1021). Open-ended and close-ended questions were used to assess self-reported effects of cannabis or cocaine on driving and frequency of driving under the influence of cannabis, cocaine, or alcohol. Results. Two dimensions of driving behavior under the influence of cocaine or cannabis were found in both qualitative and quantitative analyses: 1) physical effects and 2) reckless styles of driving. Common physical effects for both drugs were heightened nervousness, greater alertness, and poorer concentration. In terms of driving behavior, cautious or normal driving was commonly reported for cannabis, whereas reckless or reduced driving ability was frequently reported for cocaine. When comparing negative physical effects and reckless style of driving with frequency of driving under the influence of cannabis or cocaine, increased negative physical effects from cannabis were inversely related to frequency of driving under the influence of cannabis (p = .001), but other relationships were not significant. Conclusions. The findings indicate that both cannabis and cocaine have detrimental but different effects on driving. The negative physical effects of cannabis may reduce the likelihood of driving under the influence of cannabis.

Driving While Impaired (DWI) by Alcohol, Convictions Among Alcohol, Cocaine, and Cannabis Clients in Treatment

Objective. Although studies have demonstrated that clients in treatment for alcohol abuse are more at risk of driving while impaired (DWI) by alcohol than normal licensed drivers from the general population, no research was found on DWI convictions among those in treatment for abusing cannabis or cocaine. The purpose of this article is to compare DWI convictions among clients in treatment for alcohol, cannabis, cocaine, or various combinations of these substances, compared to a matched population control group. Method. A stratified random sample of driver records was drawn from seven client groups who sought treatment in 1994 for alcohol, cannabis, cocaine, or any combination of these substances (n = 445). A random sample of drivers, frequency matched by age and sex (n = 566), served as control subjects. Results. Logistic regression analysis, controlling for sex and age, was conducted to assess whether DWI convictions were elevated for each of the client groups, compared to controls. Two sets of analyses were conducted, before treatment (from 1985 to 1993) and after treatment (from 1995 to 2000). In the time period before treatment, every drug group except the “cannabis only” group had significantly more DWI convictions than controls (p < .05). In the period after treatment, the “alcohol only,” “cocaine only,” “alcohol and cocaine,” and the “cocaine and cannabis” groups still had significantly more DWI convictions than controls (p < .05). Conclusion. The results show that DWI convictions are elevated among those who abused cocaine but not among those who abused cannabis. The results suggest that cross-addiction of alcohol and cocaine is common, and problematic drinking among cocaine clients can go undetected when clients are being diagnosed for treatment.