Contamination, when members of a comparison or control condition are exposed to the event or intervention under scientific investigation, is a methodological phenomenon that downwardly biases the magnitude of effect size estimates. This study tested a novel approach for controlling contamination in observational child maltreatment research. Data from The Longitudinal Studies of Child Abuse and Neglect (LONGSCAN; N = 1354) were obtained to estimate the risk of confirmed child maltreatment on trajectories of internalizing and externalizing behaviors before and after controlling contamination. Baseline models, where contamination was uncontrolled, demonstrated a risk for greater internalizing (b =.29, p <.001, d =.40) and externalizing (b =.14, p =.040, d =.19) behavior trajectories. Final models, where contamination was controlled by separating the comparison condition into subgroups that did or did not self-report maltreatment, also demonstrated risks for greater internalizing (b =.37, p <.001, d =.51) and externalizing (b =.22, p =.028, d =.29) behavior trajectories. However, effect size estimates in final models were 27.5%-52.6% larger compared to baseline models. Controlling contamination in child maltreatment research can strengthen effect size estimates for child behavior problems, aiding future child maltreatment research design and analysis.
All Science Journal Classification (ASJC) codes
- Developmental and Educational Psychology
- Psychiatry and Mental health