Investigating The Effect Of Extra Sessions Of A Structured

1. Investigating The Effect Of Extra Sessions Of A Structured Peer Interaction Program On Social Competence Herle McGowan, University of Michigan; Robert Nix, Pennsylvania State University; Susan Murphy, University of Michigan; Karen Bierman, Pennsylvania State University; and the Conduct Problems Prevention Research Group* Background To make progress in the prevention and treatment of children’s mental health problems, we must determine not only which intervention programs are effective but also how they work (Kazdin, 2000). Examining dose-response relations between the hypothesized agents of therapeutic change and children’s functioning in clinically-relevant domains is one way of testing underlying theories of disorder and treatment. This can be difficult, however, because clinical staff members often end up providing more services to those children who demonstrate greater need over time. Thus, even when those extra intervention services are successful in preventing additional problems, a positive dose-response relation can be obscured by unmeasured selection effects. Some natural experiments circumvent this problem by providing more intervention services based on factors other than children’s need, and they have demonstrated positive dose-response relations (e.g., Seitz, Apfel, & Rosenbaum, 1991). Other studies have attempted to control statistically for measured and unmeasured selection effects associated with children’s need. Depending on the presence or absence of strong instrumental variables, such efforts have led to contradictory results regarding dose-response relations even in the same intervention program (e.g., Foster, in press; Salzer, Bickman, & Lambert, 1999). In this study within Fast Track (Conduct Problems Prevention Research Group [CPPRG], 1992), a preventive intervention program for children with conduct problems, we had the opportunity to examine dose-response relations between one component of the intervention, peer pairing, and one outcome measure, social competence. (Comprehensive evaluations of Fast Track are available elsewhere [i.e., CPPRG, 1999; 2002]). We examined dose-response relations among two groups of children: The group of children who met formal project guidelines at the end of 1st grade and received extra peer pairing in 2nd grade and the entire group of children who participated in the intervention in 2nd grade. Study Hypotheses • Fast Track will have a positive impact on children’s social competence • There will be a positive relation between peer pairing and social competence • That relation will be weaker for the children who received peer pairing as a result of staff members’ clinical judgment because unmeasured selection effects will be more problematic • Sample Characteristics • • Intervention group: n = 410 • • Control group: n = 403 • • All children in 2nd grade; children who repeated first grade were excluded • • All scored above 85th percentile among classmates for oppositional and aggressive behavior • • 55% minority; 28% female • Intervention Procedure • • In 1st grade, all families were supposed to receive the same amount of intervention services • • Intervention services consisted of social skills training, reading tutoring, peer pairing, friendship groups, parent training groups, and home visits • • In 2nd grade, children and families received different amounts of reading tutoring, peer pairing, and home visits based on project guidelines or clinical judgment of assessed need. • Description of Peer Pairing • • Weekly 30-minute structured dyadic play session • • Designed to further develop intervention children’s social skills • • Also designed to foster positive interactions between intervention children and their classmates and thereby decrease the likelihood of peer rejection • • Intervention child paired with same-sex classmate without behavior problems • • Classmate rotated each week • • Session coached by Fast Track staff member • Project Guidelines Regarding Need for Peer Pairing • • Clinical range on Teacher Report Form aggressive behavior syndrome (Achenbach, 1991), or • • Clinical range on attention problems syndrome (Achenbach, 1991), or • • Rejected status based on peer sociometric nominations • Use Clinical Judgment to Recommend Peer Pairing • • Borderline range on aggressive behavior syndrome, or • • Borderline range on attention problems syndrome, or • • Controversial status based on peer sociometric nominations, or • • Neglected status based on peer sociometric nominations, or • • Unique information staff member had about child functioning • Peer Pairing Implementation • • 65% of intervention children received some peer pairing in 2nd grade • • If children were determined by project guidelines or judged by Fast Track staff members to need peer pairing, they were supposed to receive 22 sessions • • Children actually received between 1 and 30 sessions • Assessment Procedure • • Measures to determine need for peer pairing collected at end of 1st grade • • Peer pairing sessions were delivered throughout the fall and spring semesters of 2nd grade • • Social competence outcome measure collected at end of 2nd grade • • Teacher ratings of 9 items on 6-point Likert scale (α > .80) • • Typical items: Friendly; controls temper when there is a disagreement • Intervention and Control Group Differences • • Purpose: Estimate the overall effect of participating in Fast Track (1 = intervention; 0 = control) on children’s social competence in 2nd grade • • n = 762 • • Standardized β = .07 (p = .05) • • Conclusion: Compared to control group children, intervention children displayed more social competence at the end of 2nd grade • Dose-Response Relation For Children Who Should Have Got Extra Peer Pairing and Did • • Purpose: Estimate the dose-response relation for children who met project guidelines and actually received at least one session of peer pairing in both the fall and spring • • n = 157 • • Standardized β = .18 (p = .02) • • Conclusion: When intervention services were believed to be less determined by unmeasured selection effects, there was a positive relation between peer pairing and social competence • • It is possible that there is an even stronger positive relation between • peer pairing and social competence that is reduced by our inability to • control for the use of clinical judgment inc adjusting the number of peer • pairing sessions children actually received • • It is also possible that the relation between the dose of peer pairing and • social competence among these children is actually due to other factors: • For example, staff members may have provided both more sessions of • peer pairing sessions and higher levels of other components of Fast Track • to children who needed help in improving social competence. • • We cannot distinguish between these alternative explanations without • measures of child functioning, which were believed to influence clinical • judgment, collected throughout 2nd grade • Dose-Response Relation For All Intervention Children • • Purpose: Estimate the dose-response relation for all intervention children, including those who received peer pairing as a result of project guidelines or staff members’ clinical judgment and those did not receive peer pairing at all • • n = 328 • • Standardized β = -.15 (p = .003) • • Conclusion: When use of clinical judgment was believed to result in unmeasured selection effects, there was a significant negative relation between peer pairing and social competence • • It is possible that staff members used more proximal information, which • was not recorded, about current functioning to provide more peer pairing • to those children with more serious behavior problems and less social • competence, resulting in the observed negative relation • • It is possible, although believed unlikely, that peer pairing impeded the • development of social competence for those children who did not need • peer pairing but received it anyway • • We cannot distinguish between these alternative explanations without • measures of child functioning, which were believed to influence clinical • judgment, collected throughout 2nd grade • Discussion • At the end of 2nd grade, the entire Fast Track preventive intervention program resulted in a small but statistically significant treatment effect on children’s social competence. A positive dose-response relation emerged among the children who met project guidelines at the end of 1st grade and who received at least one session of peer pairing in the fall and spring semesters of 2nd grade. Staff members were not supposed to exercise clinical judgment in adjusting services for these children, so it is believed that selection effects were less problematic. A negative dose-response relation emerged, however, when considering all intervention children. It is believed that staff members used accurate but unmeasured information about children’s functioning in 2nd grade to determine whether and how much peer pairing some children should receive, thus confounding their need for peer pairing with their response to it. In sum, it is critical to have current and valid measures of functioning at each point in which the amount of intervention services can be adjusted in preventive intervention programs. This is of particular importance in multiple component intervention programs such as Fast Track. Even if the intervention as a whole is known to be beneficial, without such measures recorded each time a decision regarding treatment is made for a particular component of the intervention, it will be impossible to determine the effect of that component. Results Plans for Analyses • Multiple linear regression equations • All analyses controlled for study site, cohort, child sex, and child race • Additional analyses controlling for 15 relevant pretreatment or 1st-grade covariates produced similar results • Additional analyses with imputed missing data produced similar results • Additional analyses with propensity scores produced similar results • Additional analyses with other outcome measures produced similar results Method Study Design • Four sites: Durham, NC; Nashville, TN; Seattle, WA; rural central Pennsylvania • Intervention and control group children randomly assigned by school • All schools served poor, high-crime neighborhoods • Two-stage teacher and parent screening process in three successive cohorts ________________________________________________________________ *Members of the Conduct Problems Prevention Research Group are, in alphabetical order, Karen Bierman, Pennsylvania State University; John Coie, Duke University; Kenneth Dodge, Duke University; Michael Foster, Pennsylvania State University; Mark Greenberg, Pennsylvania State University; John Lochman, University of Alabama; Robert McMahon, University of Washington; and Ellen Pinderhughes, Tufts University.