The sample for this study was recruited from the total enrollment of two middle schools (Grades 6–8) in central Connecticut that agreed to participate in the study. The parents of all eligible children (N=1567) in the participating middle schools were asked to provide active consent for their children to participate in the study. Parents who did not return written consent forms to the school were contacted by telephone. Twenty-two percent of parents did not return consent forms and could not be reached to obtain consent, and 6% of parents declined to provide consent. The overall participation rate in the study at baseline was 72%. Of participants who were present at baseline, 221 (20.8%) did not participate at the Time 2 assessment, and 217 (20.4%) did not participate at the Time 3 assessment, largely due to transient student enrollment in this district. Data from the school district indicate that over the 4-year period from 2000 to 2004, 22.7% of students had left the district (Connecticut Department of Education 2006). Analyses were conducted using the sample of 1,065 participants who were present at the baseline assessment, excluding participants who were present at Time 2 and/or Time 3 but not at Time 1.
