title: Empirically defining rapid response to intensive treatment to maximize prognostic utility for bulimia nervosa and purging disorder.
abstract: Rapid response (RR) to eating disorder treatment has been reliably identified as a predictor of post-treatment and sustained remission, but its definition has varied widely. Although signal detection methods have been used to empirically define RR thresholds in outpatient settings, RR to intensive treatment has not been investigated. This study investigated the optimal definition of RR to day hospital treatment for bulimia nervosa and purging disorder. Participants were 158 patients who completed ≥6 weeks of day hospital treatment. Receiver operating characteristic (ROC) analysis was used to create four definitions of RR that could differentiate between remission and nonremission at the end of treatment. Definitions were based on binge/vomit episode frequency or percent reduction from pre-treatment, during either the first four or first two weeks of treatment. All definitions were associated with higher remission rates in rapid compared to nonrapid responders. Only one definition (i.e., ≤3 episodes in the first four weeks of treatment) predicted sustained remission (versus relapse) at 6- and 12-month follow-up. These findings provide an empirically derived definition of RR to intensive eating disorder treatment, and provide further evidence that early change is an important prognostic indicator.
authors: Ryerson University, 350 Victoria Street, Toronto, Ontario M5B2K3, Canada; University Health Network, 200 Elizabeth Street, Toronto, Ontario M5G2C4, Canada. Electronic address: Danielle.macdonald@psych.ryerson.ca.
authors: Danielle E
authors: DE
authors: MacDonald
authors: University Health Network, 200 Elizabeth Street, Toronto, Ontario M5G2C4, Canada; University of Toronto, Toronto, Ontario M5S2J7, Canada.
authors: Kathryn
authors: K
authors: Trottier
authors: Ryerson University, 350 Victoria Street, Toronto, Ontario M5B2K3, Canada; University Health Network, 200 Elizabeth Street, Toronto, Ontario M5G2C4, Canada; University of Toronto, Toronto, Ontario M5S2J7, Canada.
authors: Traci
authors: T
authors: McFarlane
authors: University Health Network, 200 Elizabeth Street, Toronto, Ontario M5G2C4, Canada; University of Toronto, Toronto, Ontario M5S2J7, Canada.
authors: Marion P
authors: MP
authors: Olmsted
mesh_terms: D000293:Adolescent; D000328:Adult; D002032:Bulimia / Q000628:therapy*; D052018:Bulimia Nervosa / Q000628:therapy*; D015928:Cognitive Behavioral Therapy / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012372:ROC Curve; D012008:Recurrence
keywords: Bulimia; Eating disorders; Purging disorder; Rapid response; Receiver operating characteristic; Relapse