Families Who Benefit and Families Who Do Not: Integrating Person- and Variable-Centered Analyses of Parenting Intervention Responses

Objective: Families with disruptive child behavior are typically referred to services based on children's behavior alone, rather than on underlying mechanisms of disruptive behavior. Yet, the presence of the precise mechanisms targeted by services might be essential for intervention success. We integrated person- and variable-centered approaches to test whether families with combined disruptive child behavior and harsh/inconsistent parenting indeed benefit most from a behavioral parenting intervention in indicated prevention context, compared to families with disruptive child behavior but less harsh/inconsistent parenting, and families with less severe disruptive behavior. Method: Families (N = 387) of children aged 4 to 8 years (disruptive behavior >75^th percentile) participated in a randomized trial of the Incredible Years parenting intervention (Trial NTR3594, www.trialregister.nl). We identified different response trajectories and tested whether families with combined child and parenting difficulties had a higher probability of responding well, compared to families with only child difficulties or less severe difficulties. Results: Most intervention group families (82%) showed a nonresponse trajectory. A minority (18%) showed a response trajectory with strong reductions in disruptive behavior (Cohen's d =1.45). As expected, families with both child and parenting difficulties were most likely to respond: 20% more than families with only child difficulties, and 40% more than families with less severe difficulties. Conclusion: Incredible Years, as an indicated prevention program, benefits mainly families in which the mechanisms targeted by the intervention (ie, harsh/inconsistent parenting) is actually present, rather than all families. Careful matching of children to services based on assessments of both child and parenting behavior seems critical for intervention success. Clinical trial registration information: ORCHIDS: Study on Children's Genetic Susceptibility to Their Environment; https://www.trialregister.nl; 3594.