Objective: This study examines observations of client in-session engagement and fidelity of implementation to the Family Check-Up (FCU) as they relate to improvements in caregivers' positive behavior support (PBS) and children's problem behavior in the context of a randomized prevention trial. The psychometric properties of fidelity scores obtained with a new rating system are also explored.
Method: The FCU feedback sessions of 79 families with children with elevated problem behavior scores at age 2 were coded by trained raters of fidelity, who used an observational coding system developed specifically for this intervention model.
Results: Path analysis indicated that fidelity to the FCU results in greater caregiver engagement in the feedback session, which directly predicts improvements in caregivers' PBS 1 year later (β = 0.06, 95% CI [.007, .129]). Similarly, engagement and PBS directly predict reductions in children's problem behavior measured 2 years later (β = -0.24, 95% CI [-.664, -.019]).
Conclusions: These results suggest fidelity within the context of this randomized intervention trial. Ratings of fidelity to the FCU covary with observed improvements in parenting and children's problem behavior in early childhood. Overall reliability of the fidelity scores was found to be acceptable, but some single-item reliability estimates were low, suggesting revisions to the rating system might be needed. Accurately assessing fidelity and understanding its relationship to change during intervention studies is an underdeveloped area of research and has revealed some inconsistent findings. Our results shed light on the mixed conclusions of previous studies, suggesting that future research ought to assess the role of intervening variable effects, such as observed engagement.