Alcohol is a contributing cause of unintentional injuries, such as motor vehicle crashes. Prior research on the association between alcohol use and violent injury was limited to survey-based data, and the inclusion of cases from a single trauma centre, without adequate controls. Beyond these limitations was the inability of prior researchers to comprehensively capture most alcohol sales. In Ontario, most alcohol is sold through retail outlets run by the provincial government, and hospitals are financed under a provincial health care system. We assessed the risk of being hospitalized due to assault in association with retail alcohol sales across Ontario.
Methods and Findings
We performed a population-based case-crossover analysis of all persons aged 13 years and older hospitalized for assault in Ontario from 1 April 2002 to 1 December 2004. On the day prior to each assault case's hospitalization, the volume of alcohol sold at the store in closest proximity to the victim's home was compared to the volume of alcohol sold at the same store 7 d earlier. Conditional logistic regression analysis was used to determine the associated relative risk (RR) of assault per 1,000 l higher daily sales of alcohol. Of the 3,212 persons admitted to hospital for assault, nearly 25% were between the ages of 13 and 20 y, and 83% were male. A total of 1,150 assaults (36%) involved the use of a sharp or blunt weapon, and 1,532 (48%) arose during an unarmed brawl or fight. For every 1,000 l more of alcohol sold per store per day, the relative risk of being hospitalized for assault was 1.13 (95% confidence interval [CI] 1.02–1.26). The risk was accentuated for males (1.18, 95% CI 1.05–1.33), youth aged 13 to 20 y (1.21, 95% CI 0.99–1.46), and those in urban areas (1.19, 95% CI 1.06–1.35).
The risk of being a victim of serious assault increases with alcohol sales, especially among young urban men. Akin to reducing the risk of driving while impaired, consideration should be given to novel methods of preventing alcohol-related violence.
In a population-based case-crossover analysis, Joel Ray and colleagues find that the risk of being a victim of serious assault increases with retail alcohol sales, especially among young urban men.
Alcohol has been produced and consumed around the world since prehistoric times. In the Western world it is now the most commonly consumed psychoactive drug (a substance that changes mood, behavior, and thought processes). The World Health Organization reports that there are 76.3 million persons with alcohol use disorders worldwide. Alcohol consumption is an important factor in unintentional injuries, such as motor vehicle crashes, and in violent criminal behavior. In the United Kingdom, for example, a higher proportion of heavy drinkers than light drinkers cause violent criminal offenses. Other figures suggest that people (in particular, young men) have an increased risk of committing a criminally violent offense within 24 h of drinking alcohol. There is also some evidence that suggests that the victims as well as the perpetrators of assaults have often been drinking recently, possibly because alcohol impairs the victim's ability to judge potentially explosive situations.
Why Was This Study Done?
The researchers wanted to know more about the relationship between alcohol and intentional violence. The recognition of a clear link between driving when impaired by alcohol and motor vehicle crashes has led many countries to introduce public awareness programs that stigmatize drunk driving. If a clear link between alcohol consumption by the people involved in violent crime could also be established, similar programs might reduce alcohol-related assaults. The researchers tested the hypothesis that the risk of being hospitalized due to a violent assault increases when there are increased alcohol sales in the immediate vicinity of the victim's place of residence.
What Did the Researchers Do and Find?
The researchers did their study in Ontario, Canada for three reasons. First, Ontario is Canada's largest province. Second, the province keeps detailed computerized medical records, including records of people hospitalized from being violently assaulted. Third, most alcohol is sold in government-run shops, and the district has the infrastructure to allow daily alcohol sales to be tracked. The researchers identified more than 3,000 people over the age of 13 y who were hospitalized in the province because of a serious assault during a 32-mo period. They compared the volume of alcohol sold at the liquor store nearest to the victim's home the day before the assault with the volume sold at the same store a week earlier (this type of study is called a “case-crossover” study). For every extra 1,000 l of alcohol sold per store per day (a doubling of alcohol sales), the overall risk of being hospitalized for assault increased by 13%. The risk was highest in three subgroups of people: men (18% increased risk), youths aged 13 to 20 y (21% increased risk), and those living in urban areas (19% increased risk). At peak times of alcohol sales, the risk of assault was 41% higher than at times when alcohol sales were lowest.
What Do These Findings Mean?
These findings indicate that the risk of being seriously assaulted increases with the amount of alcohol sold locally the day before the assault and show that the individuals most at risk are young men living in urban areas. Because the study considers only serious assaults and alcohol sold in shops (i.e., not including alcohol sold in bars), it probably underestimates the association between alcohol and assault. It also does not indicate whether the victim or perpetrator of the assault (or both) had been drinking, and its findings may not apply to countries with different drinking habits. Nevertheless, these findings support the idea that the consumption of alcohol contributes to the occurrence of medical injuries from intentional violence. Increasing the price of alcohol or making alcohol harder to obtain might help to reduce the occurrence of alcohol-related assaults. The researchers suggest that a particularly effective approach may be to stigmatize alcohol-related brawling, analogous to the way that driving under the influence of alcohol has been made socially unacceptable.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0050104.
This study is further discussed in a PLoS Medicine Perspective by Bennetts and Seabrook
The US National Institute on Alcohol Abuse and Alcoholism provides information on all aspects of alcohol abuse, including an article on alcohol use and violence among young adults
Alcohol-related assault is examined in the British Crime Survey
Alcohol Concern, the UK national agency on alcohol misuse, provides fact sheets on the health impacts of alcohol, young people's drinking, and alcohol and crime
The Canadian Centre for Addiction and Mental Health in Toronto provides information about alcohol addiction (in English and French)