Communities That Care (CTC) is a prevention system designed to reduce adolescent substance use and delinquency through the selection of effective preventive interventions tailored to a community's specific profile of risk and protection. A community-randomized trial of CTC, the Community Youth Development Study, is currently being conducted in 24…

Prediction of success in a special program often guides program participant selection and treatment. If the statistical analysis used to develop such predictions is based on the special selectivity built into the program, the predictions can be misleading and the validation tests uninformative. Federal district court pretrial release data is used…

This article presents a synopsis of each of seven presentations given at a conference on design and analysis in community trial studies. Papers identify problems with community trials and discuss strengths and weaknesses associated with design and analysis strategies. Areas of consensus are summarized. (SLD)

Self-generated codes to insure student anonymity were used in a study of substance use among 2500 adolescents. Matching rates for various cohorts as a proportion of total respondents at different survey periods were less than ideal. The effects of coding and other attrition factors on the tracking are discussed. (JAZ)

A meta-analysis of school-based substance abuse prevention studies revealed that the mean proportion of subjects retained dropped from 81.4 percent at the three-month followup to 67.5 percent at the three-year followup. Researchers should interpret their results in light of these normative data and adopt second-effort strategies to reduce…

Statistical methods for program evaluation with nonexperimental data are reviewed with emphasis on circumstances in which nonexperimental data are valid. Three solutions are proposed for problems of selection bias, and implications for evaluation design and data collection and analysis are discussed. (SLD)

A controlled, parent-targeted intervention followed two cohorts of students (1,034 fifth graders and 1,244 seventh graders) to determine the effects of encouraging parents to intervene in risk factors for adolescent tobacco and alcohol use. Such programs should focus on protective factors rather than on control of risk factors. (SLD)