From efficacy to effectiveness: Comparing outcomes for youth with anorexia nervosa treated in research trials versus clinical care

•Clinic and research samples of youth with AN are largely similar.•Younger age and greater depressive symptoms predicted faster weight restoration.•Weight restoration was slower for clinical patients with a lower initial body weight.•Research and clinical setting differences may account for differences in outcome.•FBT generally appears to be effective in non-research clinical contexts.

This study examined outcomes for 84 youth with anorexia nervosa (AN) who received family-based treatment (FBT) in a research trial (randomized trial care [RTC]: n = 32) compared to fee-for-service care (specialty clinical care [SCC]: n = 52) at an outpatient eating disorder clinic. Weight was collected up to 12 months post-baseline. Survival curves were used to examine time to weight restoration as predicted by type of care, baseline demographic and clinical characteristics, and their interaction. There was not a significant main effect for type of care, but its interaction with initial %EBW was significant (p = .005), indicating that weight restoration was achieved faster in RTC compared to SCC for youth with a lower initial %EBW (i.e., ≤81), while rates of weight restoration were comparable for those with a higher initial %EBW (i.e., >81). These data suggest that FBT is as effective as it is efficacious, except for youth with lower initial body weights. Therefore, clinicians may need to be particularly active in encouraging early weight gain for this subset of patients. Nevertheless, this study suggests that FBT is appropriate as a first-line treatment for youth with AN who present for clinical care.