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.
Keywords: adolescents; anorexia nervosa; family-based treatment; fidelity.
© 2019 John Wiley & Sons, Ltd and Eating Disorders Association.