Abstract
IMPORTANCE: Antisocial behavior and adult criminality often have origins in childhood and are best addressed early in the child's life using evidence-based parenting programs. However, families with additional risk factors do not always make sufficient changes while attending such programs; these families may benefit from additional support. OBJECTIVE: To evaluate the efficacy of adding a 10-session, structured home parent support (HPS) intervention to enhance outcomes for high-risk families attending the Incredible Years Parent (IYP) program. DESIGN, SETTING, AND PARTICIPANTS: A randomized clinical superiority trial of 126 parents of children aged 3 to 7 years with conduct problems compared the IYP program plus HPS with treatment as usual of the IYP program alone. Child behavior measures were collected before and after treatment and at the 6-month follow-up. Recruitment from 19 IYP groups began February 13, 2013, and follow-up data collection was completed June 4, 2015. All data were analyzed using an intention-to-treat design with last observation carried forward. Statistical analysis took place from May 20, 2015, to March 31, 2016. INTERVENTION: Parents were randomly assigned to receive IYP program plus HPS or IYP alone. MAIN OUTCOMES AND MEASURES: The primary outcome measure was the posttreatment change in Eyberg Child Behavior Inventory Total Problem Scale (ECBI-P) score. Secondary outcomes included maintenance of change on the ECBI-P score, ECBI Intensity Scale score, and Social Competence Scale score at the 6-month follow-up; percentage of child behavior scores in the clinical range after treatment; retention; and attendance. RESULTS: A total of 126 parents (112 women and 14 men; mean [SD] age, 34.7 [8.4] years) were included; 63 parents were randomly assigned to each intervention group. Analysis of variance using intention to treat showed no significant difference between groups after treatment (P = .62). At follow-up, there was a medium effect (d = 0.63) showing a significant benefit from IYP plus HPS of 3.6 (95% CI, 0.8-6.5) on the ECBI-P score (F1,124 = 6.3; P = .01). Families receiving the IYP plus HPS intervention had significantly fewer children with child behavior scores in the clinical range after treatment (9 of 51 [17.6%]) compared with families receiving the IYP program alone (18 of 45 [40.0%]), and this status was maintained at follow-up. The HPS intervention had better retention than the IYP program (dropout, 7 [5.6%] vs 16 [12.7%]) as well as better attendance. CONCLUSIONS AND RELEVANCE: In this trial, the IYP plus HPS intervention significantly improved outcomes for the most vulnerable families at 6 months. This study demonstrated that the HPS intervention is an effective addition to the IYP program to improve engagement and implementation of IYP program strategies and enhance child behavior outcomes for the most vulnerable families. TRIAL REGISTRATION: http://anzctr.org.au Identifier: ACTRN12612000878875.