Objective
We examined rapid response among obese patients with binge-eating disorder (BED) in a randomized clinical trial testing anti-obesity medication and self-help cognitive-behavioral therapy (shCBT), alone and in combination, in primary-care settings.
Method
104 obese patients with BED were randomly assigned to one of four 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, post-treatment (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. Rapid response was unrelated to demographic and baseline clinical characteristics. Rapid response was significantly associated prospectively with remission from binge eating at post-treatment (51% versus 9% for non-rapid responders), 6-month (53% vs 23.6%), and 12-month (46.9% vs 23.6%) follow-ups. Mixed effects model analyses revealed rapid response was significantly associated with greater decreases in binge-eating, eating-disorder psychopathology, depression, and percent weight loss.
Discussion
Our findings, based on a diverse obese patient group receiving medication and self-help CBT treatments 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 treatments. 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