Neighborhood effects on the efficacy of a program to prevent youth alcohol use.

This study examines how neighborhood characteristics affect program efficacy. Data come from a randomized trial of a substance use prevention program called keepin' it REAL, which was administered to a predominantly Mexican American sample of 4,622 middle school students in Phoenix, Arizona, beginning in 1998. Multilevel models and multiple imputation techniques address clustered data and attrition. Among less linguistically acculturated Latinos, living in poorer neighborhoods and those with many single-mother families decreased program effectiveness in combating alcohol use. High neighborhood immigrant composition increased program effectiveness. Unexpectedly, the program was also more effective in neighborhoods with higher rates of crime. There were no significant effects on program efficacy for the more linguistically acculturated Latinos and non-Hispanic White students. Findings are discussed in light of theories of neighborhood social disorganization, immigrant adaptation, and social isolation.