"Data Trends" reports present summaries of research on mental health services for children and adolescents and their families. The article summarized in this "Data Trends" discusses family-based interventions and how they may have both direct and indirect effects. While the measurement of direct outcomes for a targeted group is important, a better understanding of indirect effects may contribute to improved evidence-based decision-making by practitioners, administrators, and policy-makers. The aim of this research was to "evaluate the effects of a family-based, group preventive intervention on the older siblings of targeted high-risk preschoolers". This study is an important first step in expanding an evaluation framework to consider possible indirect program outcomes. Adolescent siblings of a preschooler who received a family-based targeted intervention had better outcomes in comparison to adolescents in the control group. More evidence is required to confirm whether this was due to changes in parenting practices or other factors not measured in the study, particularly in light of the absence of an effect for the school-age siblings. As recommended by the authors, future research should include additional outcome measures; for example, a more complete teacher report data set, direct measures of parenting, and measures of changes in sibling relationships. Advancing our understanding of multicomponent family-based interventions will require theoretical models that specify pathways for change in addition to predicting outcomes. Interventions will also need to be tested across different population groups and different levels of participation. [This "Data Trends" presents a summary of: Brotman, L. M., Dawson-McClure, S., Gouley, K. K., McGuire, K., Burraston, B., & Bank, L. (2005). Older siblings benefit from a family-based preventive intervention for preschoolers at risk for conduct problems. "Journal of Family Psychology," 19, 4, 581-591.]