Clinical Trial: Rapid Response to Day Hospital Treatment in Bulimia Nervosa and Purging Disorder

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

Official Title: Rapid Response to Day Hospital Treatment in Bulimia Nervosa and Purging Disorder: A Randomized Controlled Trial of an Intervention to Facilitate Early Symptom Change

Brief Summary: Treatments for bulimia nervosa (BN) have relatively high rates of nonremission and relapse, meaning that improving treatments is a high priority in this area. Rapid response to treatment -cessation of binge eating and vomiting symptoms within the first weeks of treatment - is a robust predictor of improved post-treatment outcomes and lower relapse rates, but no study has tried to facilitate rapid response as a means of improving treatment outcomes. The present study responds to this gap in the literature by testing a 4-session CBT-based individual intervention for rapid response (i.e., "CBT-RR"), designed to augment standard day hospital (DH) treatment for BN and Purging Disorder (PD) by focusing on strategies and skills for rapid symptom interruption. CBT-RR will be compared to a matched-intensity augmentative motivational interviewing (MI) intervention. Participants will be recruited from a hospital-based day program for eating disorders, and will be randomly assigned to one of the two conditions in addition to the DH as usual. participants will be assessed at pre-intervention, post-intervention, week 4 of DH, post-DH, and 6 months follow-up. It is hypothesized that compared to those who receive MI, patients who receive CBT-RR will be more likely to exhibit a rapid response to day hospital treatment (i.e., </= 3 binge eating and/or vomiting episodes in the first 4 weeks). It is further hypothesized that patients who receive CBT-RR will exhibit fewer binge eating and/or vomiting episodes at post-DH and at 6-month follow-up. Potential mediators and moderators of these hypothesized treatment effects will be examined on an exploratory basis, including self-efficacy, motivation, and hope (potential mediators), and emotion regulation, depression, cognitive psychopathology of eating disorders, and working alliance with the therapist (potential moderators).

Detailed Summary: Cognitive behaviour therapy (CBT) is the most empirically supported treatment for bulimia nervosa (BN) and related disorders, yet approximately 1/3 of completers do not remit, there is a substantial treatment attrition rate, and 1/3 of remitted patients will relapse within the first 2 years. Improving CBT is an important research prerogative. Motivational interviewing (MI) is an augmentative intervention that has been investigated to improve CBT, but reviews indicate that it is not efficacious with eating disorders. The failure of MI with eating disorders has led to consideration that focusing on early behaviour change might be a more productive therapeutic strategy. Rapid response to treatment for eating disorders has been reliably identified as a prognostic indicator in eating disorders. For BN and similar disorders, rapid response is the rapid reduction of binge eating, vomiting, and dietary restriction during the first few weeks of treatment. Numerous studies have indicated that patients who rapidly respond to treatment are significantly more likely to be remitted at post treatment and significantly less likely to relapse, compared to those who respond more slowly. No preexisting clinical, demographic, personality or other factors have clearly emerged to account for this effect. Given that rapid response has clear prognostic importance, and given that research has failed to identify mechanisms driving this finding, this study seeks to determine whether rapid response can be facilitated clinically using a targeted intervention designed to provide patients with specific behavioural skills to decrease their bulimic symptoms rapidly. Improving remission and relapse rates is a high priority in the eating disorders research field. the investigators already know that cognitive and behavioural strategies have efficacy for eating disorders, but existing treatments need improvement. Rapid response is an area that has been frequently described and has clear prognostic impo
Sponsor: University Health Network, Toronto

Current Primary Outcome:

• Rapid response to day hospital treatment [ Time Frame: First 4 weeks of day hospital treatment ]
  Rapid response is a binary outcome variable (yes/no) of early bulimic symptoms. Rapid responders exhibit a total of three or fewer binge and/or vomit and/or laxative episodes in the first four weeks of day hospital treatment for eating disorders.
• Changes in bulimic symptom frequency [ Time Frame: Each of the following: Baseline, first 4 weeks of day hospital, last 4 weeks of day hospital, and months 1-6 in follow-up. ]
  Bulimic symptoms (binge eating and/or vomiting and/or laxative use) will be totalled for each 4 week period and changes modelled over time at the following time points: Baseline, first 4 weeks of day hospital, last 4 weeks of day hospital, and months 1-6 in follow-up.

Original Primary Outcome: Same as current

Current Secondary Outcome:

• End-of-Day Hospital Outcome [ Time Frame: Participants will be assessed at end of day hospital stay, an expected average of 8 weeks. ]
  Outcome is a binary outcome variable, remitted (yes/no). Remitted patients have one or fewer binge and/or vomit and/or laxative episodes in the last 4 weeks of day hospital treatment. Non-remitted patients have 2 or more episodes in this same period. Day hospital stays are expected to consist of an average of 8 weeks of treatment.
• 6-month relapse rate [ Time Frame: 6 months after discharge from day hospital ]
  Relapse is a binary outcome variable (yes/no). Relapsed patients have an average of 4 or more binge and/or vomit and/or laxative use episodes per month for three consecutive months, beginning in the first 6 months after discharge from day hospital program. Non-relapsed patients have bulimic symptoms below this threshold.

Original Secondary Outcome: Same as current

Information By: University Health Network, Toronto

Dates:
Date Received: April 23, 2015
Date Started: May 2014
Date Completion:
Last Updated: May 13, 2016
Last Verified: May 2016