Predicting meaningful outcomes to medication and self-help treatments for binge-eating disorder in primary care: The significance of early rapid response

Abstract

Objective: We examined rapid response among obese patients with binge-eating disorder (BED) in a randomized clinical trial testing antiobesity medication and self-help cognitive-behavioral therapy (shCBT), alone and in combination, in primary-care settings.

Method: One hundred four obese patients with BED were randomly assigned to 1 of 4 treatments: sibutramine, placebo, shCBT + sibutramine, or shCBT + placebo. Treatments were delivered by generalist primary-care physicians and the medications were given double-blind. Independent assessments were performed by trained and monitored doctoral research clinicians monthly throughout treatment, posttreatment (4 months), and at 6- and 12-month follow-ups (i.e., 16 months after randomization). Rapid response, defined as ≥65% reduction in binge eating by the fourth treatment week, was used to predict outcomes.

Results: Rapid response characterized 47% of patients, was unrelated to demographic and baseline clinical characteristics, and was significantly associated, prospectively, with remission from binge eating at posttreatment (51% vs. 9% for nonrapid responders), 6-month (53% vs. 23.6%), and 12-month (46.9% vs. 23.6%) follow-ups. Mixed-effects model analyses revealed that rapid response was significantly associated with greater decreases in binge-eating or eating-disorder psychopathology, depression, and percent weight loss.

Discussion: Our findings, based on a diverse obese patient group receiving medication and shCBT for BED in primary-care settings, indicate that patients who have a rapid response achieve good clinical outcomes through 12-month follow-ups after ending treatment. Rapid response represents a strong prognostic indicator of clinically meaningful outcomes, even in low-intensity medication and self-help interventions. Rapid response has important clinical implications for stepped-care treatment models for BED.

Clinical trial registration: clinicaltrials.gov: NCT00537810 (PsycINFO Database Record

(c) 2015 APA, all rights reserved).

Figures

Figure 1. Frequency of Binge-eating Over Time by Rapid Response Status

Frequency of binge-eating (per week) by participants with rapid response versus without rapid response over time based on two complementary assessments. The top figure shows binge-eating frequency during the major assessment points through the 12-month follow-up. The bottom figure shows binge-eating frequency based on the Eating Disorder Examination – Questionnaire monthly during the course of treatment and at 6- and 12-month post-treatment follow-up assessments. The data shown are based on estimated marginal means (derived from mixed models analyses of log transformed binge-eating data) for all N=104 participants.

Figure 2. Depression (Beck Depression Inventory (BDI) Scores) by Rapid Response Status

Depression (Beck Depression Inventory [BDI]) scores for participants with rapid response versus without rapid response monthly during the course of treatment and at 6- and 12-month post-treatment follow-up assessments. The data shown are based on estimated marginal means (derived from mixed models analyses) for all N=104 participants.

Figure 3. Percent Weight Loss by Rapid Response Status

Percent weight by participants with rapid response versus without rapid response monthly during the course of treatment and at 6- and 12-month post-treatment follow-up assessments. The data shown are based on estimated marginal means (derived from mixed models analyses) for all N=104 participants.