Therapist adherence to family-based treatment for adolescents with anorexia nervosa: A multi-site exploratory study

Objective: This exploratory study is the first to examine family-based treatment (FBT) adherence and association to treatment outcome in the context of a large-scale, multi-centre study for the treatment of adolescents with anorexia nervosa. Method: One hundred and ninety recorded FBT sessions from 68 adolescents with anorexia nervosa and their families were recruited across multiple sites (N = 6). Each site provided 1–4 tapes per family over four treatment time points, and each was independently rated for therapist adherence. Results: There were differences in adherence scores within and between sites. ANOVA produced a main effect for site, F(5, 46) = 8.6, p <.001, and phase, F(3, 42) = 12.7, p <.001, with adherence decreasing in later phases. Adherence was not associated to end of treatment percent ideal body weight after controlling for baseline percent ideal body weight (r =.088, p =.48). Conclusions: Results suggest that FBT can be delivered with adherence in phase one of treatment. Adherence was not associated with treatment outcome as determined using percent ideal body weight.