title: Intervention Effectiveness of The Incredible Years: New Insights Into Sociodemographic and Intervention-Based Moderators.
abstract: We tested the effectiveness of the preventive behavioral parent training (BPT) program, The Incredible Years (IY), and the independent effects of previously suggested sociodemographic and intervention-based moderator variables (i.e., initial severity of externalizing problem behavior, child gender, social economic status, family composition, and number of sessions parents attended), in a large-scale randomized controlled trial. Questionnaire and observation data from 387 parents and children ages 4-8 years (Mage= 6.21, SD = 1.33, 55.30% boys) across pretest, posttest, and 4-month follow-up were analyzed, using full intention-to-treat analyses and correcting for multiple testing. IY was successful in decreasing parent-reported child externalizing behavior (Cohen's d = 0.20 at posttest, d = 0.08 at follow-up), increasing parent-reported (d = 0.49, d = 0.45) and observed (d = 0.06, d = 0.02) positive parenting behavior, and decreasing parent-reported negative parenting behavior (d = 0.29, d = 0.25). No intervention effects were found for reported and observed child prosocial behavior, observed child externalizing behavior, and observed negative parenting behavior. Out of 40 tested moderation effects (i.e., 8 Outcomes × 5 Moderators), only three significant moderation effects appeared. Thus, no systematic evidence emerged for moderation of IY effects. The present multi-informant trial demonstrated that many previously suggested moderators might not be as potent in differentiating BPT effects as once thought.
authors.affiliation: University of Amsterdam; Utrecht University.
authors.forename: Joyce
authors.initials: J
authors.lastname: Weeland
authors.affiliation: University of Amsterdam; Utrecht University.
authors.forename: Rabia R
authors.initials: RR
authors.lastname: Chhangur
authors.affiliation: University of Amsterdam.
authors.forename: Danielle
authors.initials: D
authors.lastname: van der Giessen
authors.affiliation: Utrecht University.
authors.forename: Walter
authors.initials: W
authors.lastname: Matthys
authors.affiliation: Utrecht University.
authors.forename: Bram Orobio
authors.initials: BO
authors.lastname: de Castro
authors.affiliation: University of Amsterdam. Electronic address: g.overbeek@uva.nl.
authors.forename: Geertjan
authors.initials: G
authors.lastname: Overbeek
mesh_terms: D002648:Child; D002652:Child Behavior / Q000523:psychology; D002653:Child Behavior Disorders / Q000517:prevention & control*; D002675:Child, Preschool; D003156:Community Mental Health Services / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D010287:Parent-Child Relations; D016487:Parenting / Q000523:psychology*; D010290:Parents / Q000193:education*; D011340:Problem Solving; D012919:Social Behavior; D012959:Socioeconomic Factors
keywords: The Incredible Years; externalizing disorders; moderators; prevention; randomized controlled trial