Who Benefits and How Does It Work? Moderators and Mediators of Outcome in an Effectiveness Trial of a Parenting Intervention

We examined mediators and moderators of change in conduct problems, in a multiagency randomized trial of the Incredible Years parenting program. Preschoolers (n = 153) at risk for conduct problems were randomly assigned to intervention (n = 104) and wait-list (n = 49) groups. Boys and younger children, and those with more depressed mothers, tended to show greater improvement in conduct problems post-intervention. Other risk factors (i.e., teen or single parenthood, very low income, high initial levels of problem behavior) showed no predictive effects, implying intervention was at least as successful at helping the most disadvantaged families, compared to more advantaged. Mediator analyses found change in positive parenting skill predicted change in conduct problems.