TABLE 2—
Intent-to-Treat Analyses: Significant Results of Analysis of Covariance Immediately After Intervention and at 6-Month Follow-Up
| Outcomes | Experimental Group, Adjusted Mean (SE) | Control Group, Adjusted Mean (SE) | Group F Value (P) | School × Group F Value (P) |
| Immediately after intervention (time 2) (n = 1220)a | ||||
| Progression of drug use | 1.98 (0.08) | 2.02 (0.08) | … | 2.28 (.02) |
| 6-month follow-up (time 3) (n = 1178)b | ||||
| Conventional peer bonding | 1.78 (0.03) | 1.87 (0.03) | 5.24 (.02) | … |
| High-risk peer bonding | 1.76 (0.04) | 1.62 (0.04) | 8.09 (.01) | … |
| Prosocial weekend activities | 3.87 (0.10) | 4.23 (0.10) | 6.89 (.01) | … |
Note. Predictors = group and school × group; covariates = baseline score, grade, and gender.
an = 608 in the experimental group and n = 612 in the control group.
bn = 597 in the experimental group and n = 581 in the control group.