Sustained, fade-out or sleeper effects? A systematic review and meta-analysis of parenting interventions for disruptive child behavior.

Parenting interventions are known to reduce disruptive child behavior immediately post intervention. But it is largely unknown how reduced disruptive behavior develops in the months and years after the intervention. The present systematic review and multilevel meta-analysis examines whether improvements in disruptive child behavior after parenting intervention are maintained (i.e., sustained effects), fall back (i.e., fade-out effects), or increase further (i.e., sleeper effects). We identified 40 randomized controlled trials with follow-up assessments (up to three years) that generated 91 effect sizes. Mean effect size of post-intervention change was d=0.01, 95% CI [-0.05, 0.07], p=0.78. This lack of change suggests that parenting interventions lead to sustained effects on disruptive behavior. However, there was heterogeneity within and between trials, indicating that some interventions, or interventions under certain circumstances do show fade-out or sleeper effects. None of the moderators tested (i.e., length of follow-up and initial intervention success) explained this heterogeneity. We conclude that parenting interventions generally lead to sustained reductions in disruptive child behavior, at least until three year after intervention. Better understanding is needed of when and why sustainability is stronger in some cases than in others.