PloS one
The impact of contamination bias when replicating maltreatment effects on child behavior problems
By Olson AE, Felt JM, Greifer N and 4 others.
Abstract
Background
Contamination, when members of a comparison condition receive or are exposed to a treatment under investigation, can bias the direction, statistical significance, and magnitude of treatment effects.
Objective
This pre-registered study examined whether contamination biased estimates when replicating child maltreatment effects on two established outcomes, externalizing and internalizing behavior problems.
Methods
A multi-wave, U.S. national probability sample of children and families involved with child protective services (N = 4000; Age = 0-17.5; Sex = 48% Female; Race = 60% White; Ethnicity = 30% Hispanic). Child maltreatment and comparison conditions were established using official case records and contamination was identified as caregiver-reported maltreatment for those children assigned to the comparison condition. Outcomes were 6-month frequencies of externalizing and internalizing behaviors, represented in T-scores, three years post-maltreatment exposure.