Strong Design and Comprehensive Analysis of the Child-Parent Center Study

摘要

Our study of the Child-Parent Center (CPC) early intervention program1 found that participation was associated with greater health and well-being by age 24 years. In one of the editorials that accompanied our article,2 Olds criticized the study as having limited validity because it was not a randomized controlled trial (RCT). Olds advocated that only RCTs can yield valid and confident estimates of effects. Indeed, only 1 of the 14 paragraphs in the editorial discussed the actual study at all, with the rest focused on particular research questions that the early intervention field should address with RCTs.As described in the article and in many supporting studies, the findings of the CPC study have high validity for many reasons: (1) the program was implemented in the most economically disadvantaged areas and program staff sought those who were most at risk; (2) the control group was mostly selected from randomly chosen schools; (3) the entire control group participated in an enriched all-day kindergarten intervention compared with only 60% of the CPC group, and 15% of the control group had attended a Head Start preschool; and (4) the project has, since its inception, completed many studies of possible selection bias due to both treatment selection and attrition, and findings have consistently showed positive effects of the program.3"7 This extensive robustness testing is unique in the intervention field and has been one of the hallmarks of the study.