The Impact of a Preventive Intervention on Persistent, Cross-Situational Early Onset Externalizing Problems.

The Nurse-Family Partnership (NFP) home visiting intervention for low-income first-time mothers was evaluated for its preventive impact on persistent, cross-situational early-onset externalizing problems (EXT). Seven hundred thirty-five women in the Denver, CO, area were randomly assigned into one of two active conditions (nurse or paraprofessional home visiting from pregnancy through child age 2) or a control group in which children were screened and referred for behavioral and developmental problems. Externalizing behavior was assessed by parent report when the children were 2, 4, 6, and 9 years old; teachers provided reports at ages 6 and 9. Latent profile analyses suggested the presence of persistent, cross-situational early onset EXT in approximately 6 to 7% of girls and boys. The intervention deflected girls away from these EXT and toward a pattern marked by a persistent moderate elevation of externalizing behavior that was evident at home and not at school. This finding should be interpreted cautiously given the small number of girls with the elevated EXT. Surprisingly, the intervention also moved girls away from stable low level externalizing behavior toward the moderately elevated pattern. Both of the significant effects on girls' externalizing behavior were modest. No statistically significant effects were found for boys' externalizing behaviors, which exhibited a somewhat different patterning across time and reporter. Effect sizes were generally similar for the nurse and paraprofessional-visited groups. The results are discussed in the context of prior efforts to prevent early EXT and emerging evidence on the normative development of externalizing behavior.