Community Prevention Trial Reduces Risky Drinking, Alcohol-Related Crashes and Trauma -- Environmental strategies, plus public education and awareness prove effective
A study reported in the November 8 issue of the Journal of the American Medical Association (Volume 284, Number 18) shows that communities that undertake comprehensive prevention strategies can effectively reduce alcohol-related traffic crashes and injuries from crashes and assaults. Relative to matched comparison sites, intervention communities (two in California and one in South Carolina) experienced marked reductions in alcohol-related crashes, nighttime injury crashes, injuries due to assault, and assaults that required hospitalization, as well as in self-reported alcohol consumption, heavy drinking, and drinking and driving.
First author Harold D. Holder, Ph.D., and his colleagues at the Prevention Research Center, Berkeley, California, and the Pacific Institute for Research and Evaluation reported the gains at the conclusion of the April 1992-December 1996 Community Prevention Trial (CPT). The National Institute on Alcohol Abuse and Alcoholism supported the study.
"Dr. Holder and his colleagues demonstrate that complex community systems can be studied rigorously-a formidable achievement given the complexity of the environment," said NIAAA Director Enoch Gordis, M.D. AThe CPT provides powerful new evidence that comprehensive, coordinated environmental prevention programs can be effective in reducing alcohol-related injuries and accidents in the community."
In a comprehensive public health approach, the CPT involved local city councils, the police, the media, alcohol sales and service institutions, and others in an array of interventions designed to
- mobilize communities through coalition-building and media advocacy,
- encourage responsible beverage service,
- reduce underage drinking by limiting access to alcohol,
- increase local enforcement of drinking and driving laws, and
- limit alcohol access through zoning measures.
Earlier studies had shown each intervention to be independently effective but they had never before been combined in a comprehensive program.
Rather than drinking per se the CPT targeted environmental conditions and drinking patterns that are likely to be antecedents to trauma. While the proportion of respondents who reported drinking remained essentially unchanged across the five-year study, the intervention communities experienced substantial reductions in the quantity of alcohol consumed per occasion.
The researchers implemented the interventions in successive stages tied to specific effectiveness indices. For example, phase 1 and phase 2, which focused in large part on drunk driving prevention, were indexed by police use of breath-testing devices and roadside checkpoints, respectively. The date of onset for each phase provided an intervention "pulse" that enabled the researchers to track intervention effects on drinking behavior and alcohol-related injuries.
Outcome measures included self-reported and objective measures. To obtain the self-reports, the investigators placed 120 random general population telephone calls each month for 66 months in both the intervention and control communities. For the objective outcomes, they relied on routinely collected traffic and hospital discharge data. They found that, at five years, nighttime car crashes with injuries had declined by 10 percent, crashes involving drunk drivers had declined by 6 percent, injuries due to assault had fallen by 43 percent and hospitalized assaults by 2 percent. Self-reported alcohol consumption per drinking occasion declined by 6 percent, having "too much to drink" declined by 49 percent, and driving while "over the legal limit" declined by 51 percent in the intervention relative to the control communities.
The study has several limitations, the authors point out: The intervention communities were not randomly selected, and the interventions may have introduced a bias that influenced self-reports. Even so, "the CPT shows that the public need not remain passive recipients of trauma caused by heavy drinking," said Dr. Holder.
Research interest in community-based prevention programs is based in part on the successes from the study of cardiovascular disease, which began more than 20 years ago. The heart disease interventions were helpful in changing behaviors by reducing smoking and dietary fat intake and by controlling blood pressure, and have led to a lower incidence of acute coronary syndromes such as heart attack and unstable angina. During recent years, alcohol researchers have adapted these approaches in community interventions to prevent and reduce youth alcohol use and drinking and driving (see News Releases at http://www.niaaa.nih.gov).
"While education and public awareness campaigns alone are unlikely to prove effective in reducing the rate of alcohol-related injury and death, a combination of those programs with some of the environmental strategies is mutually reinforcing and thus can be successful," Dr. Holder writes.
For interviews with Dr. Holder, telephone the Pacific Institute for Research and Evaluation and Prevention Research Center in Berkeley, California (510/486-1111). For interviews with Dr.Gordis, telephone NIAAA Press (301/443-0595). For additional information on alcohol research, please visit http://www.niaaa.nih.gov/