Moderators of change in problem behavior Running Head: MODERATORS OF OUTCOME Moderators of Outcome in a Brief Family-Centred Intervention for Preventing Early Problem Behavior

This study investigates moderators of change in an empirically supported family-centered intervention (the Family Check Up) for problem behavior in early childhood, among low-income families screened for risk family stress and early onset problem behavior. 731 2-3 year-olds were randomized to the Family Check Up intervention, or to a control group. Latent Growth Models examined socio-demographic and parent psychological risk factors as potential moderators of change in problem behavior between age 2, 3 and 4. Results revealed two moderators of intervention effectiveness. Caregivers with the lowest educational levels were more responsive to the family-centered intervention, and two-parent families were more responsive to the intervention. Other risk factors showed no predictive effects. Overall, findings suggest that this brief family-centered intervention can be equally effective in reaching the most distressed and disadvantaged families, compared to those who are more advantaged. However, these results suggest that more attention is needed to address the intervention needs of single parent families in reducing problem behavior in early childhood.