A University of Washington study found that the positive influence of this community-led system was sustained through high school.

"These towns are safer now, because there are significantly fewer teens fighting, stealing or doing things under the influence that they'd regret later," said J. David Hawkins, lead author and founding director of the Social Development Research Group, affiliated with the UW School of Social Work.

The results also suggest that teens growing up in Communities That Care towns will go on to have healthier lives.

"Kids who don't try alcohol until after age 18 are much less likely to become addicted," Hawkins said. And, "kids who refrain from smoking or crime before age 18 are very unlikely to start either later."

The findings are published in the Dec. 9 issue of the Journal of the American Medical Association Pediatrics.

Communities That Care was developed by Hawkins with co-author Richard Catalano, director of the UW's Social Development Research Group. The prevention system is led by a coalition of diverse stakeholders in each community who use surveys of young people to identify risk factors that are widespread in their town and protective factors that need strengthening.

Choosing from a list of prevention approaches proven to work, the local coalitions implement policies and programs that best address their communities' needs.

Since 2003, the UW team has tracked the effectiveness of this strategy by measuring experiences and behaviors among a sample of about 4,500 fifth-grade students living in 24 small- to moderate-size towns (between 1,500 and 50,000 residents) in seven states: Colorado, Illinois, Kansas, Maine, Oregon, Utah and Washington. Half of the towns participated in Communities That Care, and the other towns served as a control group and did not receive training to use the Communities That Care system.

The new study followed those fifth graders through high school and found that by the end of 12th grade, the rates of never engaging in violence, delinquency, drinking and smoking in the sample in Communities That Care towns were significantly lower than in communities that did not receive training to use the system.

By the end of high school, 32 percent of teens from Communities That Care towns had never had an alcoholic drink compared with 23 percent of teens from the control towns.

That 10 percentage point is a shift in peer culture, Hawkins said. "Now you're one in three -- not one in four -- who hasn't tried alcohol. Abstaining from alcohol appears more popular."

Fewer Communities That Care teens tried smoking cigarettes by the end of high school: half of teens in the program had avoided smoking compared with 43 percent of the control group.

Delinquency -- including fighting, vandalism, shoplifting, carrying a handgun and being arrested -- also diminished with the program. Fifty-eight percent of Communities That Care teenagers reported involvement in delinquent acts by the end of 12th grade, compared with 67 percent of their peers in control communities.

A previous benefit-cost analysis showed $5.30 saved in future costs to society for every $1 spent on Communities That Care based on earlier reported results on the prevention of smoking and delinquency.

"We're learning that communities that initiate this science-based approach to reducing risk and strengthening protection in the middle school years can have lasting effects on whether kids start to engage in risky behaviors all the way through high school. That change will bring future benefits both to those young people and their communities," Hawkins said.