Abstract
BACKGROUND: Empirical evidence supports the efficacy of behavioral online parent training. However, further large trials in school-age children with externalizing behavior problems and analyses on the impact of additional therapist support are needed. This three-arm randomized controlled trial examined the efficacy of guided and unguided web-assisted self-help (WASH) for parents of children with externalizing behavior problems. METHODS: Parents of 431 children (6-12 years) with elevated externalizing symptoms were randomly assigned to either treatment as usual (TAU), a 6-month behavioral WASH intervention (WASH+TAU), or WASH plus telephone-based support (WASH+S+TAU). Assessments took place at baseline and at 3, 6, and 12 months. The primary outcome was child externalizing symptoms as rated by a clinician blinded to condition; secondary outcomes were parent-rated child externalizing symptoms, internalizing symptoms, functional impairment, quality of life, parenting practices, and parental internalizing symptoms. (German Clinical Trials Register (DRKS): DRKS00013456; URL: https://drks.de/search/de/trial/DRKS00013456; registered on January 3rd 2018). RESULTS: Linear mixed models for repeated measures revealed a significant overall intervention effect on blinded clinician-rated externalizing symptoms at 6 months in both the intention-to-treat sample and per-protocol samples, with at least 25% (PP25) or 40% treatment utilization (PP40), respectively (intention-to-treat: p = .017). Subsequent pairwise comparisons revealed a greater symptom reduction in WASH+S+TAU than in the other conditions (intention-to-treat: WASH+S+TAU vs. WASH+TAU: p = .029, d = -0.28, 95% CI [-0.54, -0.03]; WASH+S+TAU vs. TAU: p = .009, d = 0.34 [-0.59, -0.09]). At 12 months, a significant overall effect on blinded clinician-rated externalizing symptoms only emerged in the PP40 sample (p = .035). Secondary analyses revealed an overall effect on child functional impairment at 12 months (intention-to-treat and per-protocol analyses) and on negative parenting behaviors at 6 months in the PP40 sample. For both variables, pairwise comparisons demonstrated significant differences between WASH+S+TAU and TAU. CONCLUSIONS: Parent-directed WASH is effective in reducing blinded clinician-rated externalizing symptoms, but only when combined with additional support.