The Trajectory of Fidelity in a Multiyear Trial of the Family Check-up Predicts Clinically Significant Change in Child Problem Behavior

Therapist fidelity to evidence-based family interventions has consistently been linked to child and family outcomes. However, few studies evaluate change in fidelity of therapists over repeated sessions with the same family. Evaluating drift could potentially illuminate the provider-client interactional processes that promote or inhibit intervention effectiveness via protocol delivery. We examined therapist fidelity with the same families across the first four years of the Early Steps Multisite Trial using the Family Check-Up (FCU) to: (1) evaluate drift in fidelity to the FCU and (2) examine the relation between within-family drift in fidelity with clinically significant change in parent-reported child problem behavior from age 2 to age 7.5 years. We hypothesized that changes in fidelity over time would be related to intervention outcomes for families with children rated in the clinical range for behavior problems at study entry.

This study examined a subsample of 79 families from the original 731 mother–child dyads (49% female) recruited from the Women, Infants, and Children Nutritional Supplement Program in three geographically and culturally diverse U.S. regions. Families were selected from the larger sample of intervention families based on having a child in the clinical range of problem behavior. Fidelity to the FCU is assessed using the COACH rating system (Dishion et al., 2010), which jointly assesses adherence to the FCU model and the quality of the delivery (competent adherence). The CBCL was used to assess child behavioral problems at age 2 (Achenbach & Rescorla, 2000) and age 7.5 (Achenbach & Rescorla, 2001). We calculated clinically meaningful change from ages 2 to 7.5 years on the Externalizing problems subscale using the Clinical Change Index (Jacobson & Truax, 1991), based on 3 categories: improved to the normal range, remained in the clinical range, and significantly deteriorated.

Latent growth modeling using Bayesian estimation revealed a significant decline in fidelity over time (M = – 0.34, SD = 0.34) and steeper declines were related to less improvement in caregiver-reported problem behaviors from baseline at age 2 to age 7.5 (B = 3.33, p= .05).

The analyses indicated that fidelity declined over time in general, and that steeper decline was associated with less change in child problem behavior from age 2 to 7.5. These findings add to the literature concerning the need to monitor and reassess therapist fidelity to an evidence-based practice over time to optimize family benefits. It appears crucial to develop fidelity of implementation monitoring systems involving the use of evidence-based fidelity assessment measures to successfully transfer evidence-based interventions to community service delivery systems.