In the Absence of Clear Causation, Casting a Wider Net for Prevention

Although substantial evidence shows a positive association between nonparental child care arrangements and higher child weight status,1–6 the question of causality has remained wide open until now. In this issue of Pediatrics, Isong et al7 take some creative approaches to their analysis of cohort data to better understand the nature of the association. When using conventional models, analyses resulted in findings similar to previous studies: children in nonparental child care have a higher risk of subsequent obesity than children in parental care. However, when using models that adjust for the unmeasured confounders endemic to any nonexperimental study, no such association was found. The authors conclude that “unobserved” differences in family circumstances may contribute to parents’ selection of child care, which then confounds the association between child care and weight status.7 This article is interesting, has face validity, and certainly will help assuage working parents’ guilt: placing children in child care may not, in fact, put their children at risk for obesity. All this is reassuring, but leaves us with many unanswered questions ripe for research to guide policy and pediatric guidance. The authors suggest further exploration of the factors … Address correspondence to Eliana M. Perrin, MD, MPH, Department of Pediatrics, 333 South Columbia St, 231 MacNider Building, CB 7225, Chapel Hill, NC 27599-7225. E-mail: eliana_perrin{at}med.unc.edu