Does a maternal history of childhood maltreatment influence prevention program impact on child outcomes? Exploratory findings from a randomized controlled trial in British Columbia, Canada

Background Nurse-home visiting programs starting prenatally are a promising approach for preventing child maltreatment including injuries. Understanding which families benefit the most can inform policies to ensure greater impact and efficiency. Objective We investigated whether maternal history of childhood maltreatment (CM) moderated Nurse-Family Partnership (NFP) impact on child outcomes. Participants and setting We utilized secondary data from the Canadian NFP randomized controlled trial (RCT) involving 739 mothers aged 14–24 years and their 737 children in British Columbia (data collected 2013–2019). Methods Baseline data, including maternal CM history, were collected during pregnancy and before random assignment to existing services or NFP plus existing services. Data on main child outcome indicators: injuries (emergency department events), problem behaviour and language (maternal report) and language and cognition (in-home observations) were collected at age two years. Results Many maternal participants reported CM exposure (73.1%), including 57% medium-to-severe and 41.8% severe thresholds. CM history significantly moderated NFP impacts on selected child outcomes including injuries (adjusted differences in rate differences =102.92, 95% CI: 15.18, 193.45) and language via maternal report (adjusted differences in mean differences = −82.52, 95% CI: −150.77, −14.27). Conclusions A maternal history of CM moderated NFP impacts on injuries and language, but not all child outcomes examined. Researchers are encouraged to harness existing RCT data to learn how prevention program outcomes vary across populations. Policymakers may then apply this nuanced guidance to inform the refinement of prevention programs for families with unmet needs, fulfilling the ethical obligation to ensure that programs are effective for all.