All intervention components were guided by detailed manuals, and annual cross-site trainings and weekly supervisory meetings served to standardize intervention approaches across site. Multiple strategies were used to increase parental involvement (e.g., transportation, child-care, refreshments, nominal payment ($15) for each group session attended). Only a few families (6 % of the sample) declined to initiate participation in the intervention. Of the 94 % participating, 79 % of the parents and 90 % of the children attended at least 50 % of the sessions offered. Intervention participation decreased gradually across the years, and by grade 6, 10 % of the families had moved outside of the service delivery area. During the middle school years, approximately 15 % of the youth were rated as low risk, but a majority continued to receive some services through tenth grade. On average, 63 % of the parents and 78 % of the youth attended group sessions held in middle school (parent mean of 3.8 meetings attended; youth mean of 6.4 meetings attended). Individualized services were provided to 80 % of the parents and 78 % of the youth during grades 8–10.
