Preventing preschool mental health problems: Population-based cluster randomized controlled trial

This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.Objective Prevention of child behavior problems may reduce later mental health problems. We compared the effectiveness, at the population level, of an efficacious targeted prevention program alone or following a universal parenting program. Method Three arm, cluster randomized controlled trial. 1353 primary caregivers and healthy eight-month-old babies recruited July 2010 to January 2011 from well-child centers (randomization unit). Primary outcome: Child Behavior Checklist (CBCL) externalizing and internalizing scales* at child age three and 4.5 years. Secondary outcomes: Parenting Behavior Checklist* and over-involved/protective parenting (primary caregiver report). Secondary caregivers completed starred measures at age three. Results Retention was 76% and 77% at ages three and 4.5 years, respectively. At three years, intention-to-treat analyses found no statistically significant differences (adjusted mean difference (95% CI; p-value)) for externalizing (Targeted versus Usual Care -0.2 (-1.7 to 1.2; p= 0.76); Combined versus Usual Care 0.4 (-1.1 to 1.9; p=0.60)) or internalizing behavior problems (Targeted versus Usual Care 0.2 (-1.2 to 1.6; p= 0.76); Combined versus Usual Care 0.4 (-1.1 to 2.0; p=0.58)). Primary outcomes were similar at 4.5 years. At three years, primary and secondary caregivers reported less over-involved/protective parenting in both the Combined and Targeted versus Usual Care arm; secondary caregivers also reported less harsh discipline in the Combined and Targeted versus Usual Care arm. Mean program costs per family were $A218 (Targeted arm) and A$682 (Combined arm). Conclusion When translated to the population level by existing staff, pre-existing programs appeared ineffective in improving child behavior, alone or in combination, but improved parenting