Peer Coaching to Support Weight Management in Primary Care: A Cluster Randomized Clinical Trial.

Importance: Employing peer coaches to provide weight management counseling in primary care could address patient- and clinician-level barriers to obesity care, improve outcomes, and boost engagement in weight management programs. Objective: To evaluate the efficacy of peer coaching to deliver a low- to moderate-intensity intervention for weight management compared with enhanced usual care (EUC). Design, Setting, and Participants: This 2-arm, cluster randomized clinical trial was conducted from November 2017 to August 2021 at a single US Department of Veteran Affairs (VA) site. Primary care physicians (PCPs) and their patients with a body mass index (calculated as weight in kilograms divided by height in meters squared) of at least 25 (overweight) or 30 or more (obesity) were invited to participate. Enrollment was stopped early due to the COVID-19 pandemic, when weight management services at the VA site transitioned to primarily virtual care. PCPs were randomized to either the peer coaching (ie, Peer-Assisted Lifestyle) intervention or EUC arm, and their patients received the corresponding treatment for those arms. Data were analyzed according to the intention-to-treat principle from February 2023 and July 2024. Interventions: Patients in the peer coaching arm completed a tablet-based, goal-setting tool and received 1 in-person and up to 12 individual peer-coaching telephone sessions over 1 year. Peer coaches were veterans with a bachelor's degree and training for a minimum of 20 hours. Patients in the EUC control arm received health education materials. Main Outcomes and Measures: The primary outcome was mean (SE) change in weight (in kilograms) at 12 months. Secondary outcomes included mean (SE) weight change in percentage, proportion of patients achieving 5% or higher weight loss, and change in waist circumference in inches. Results: A total of 20 PCPs (11 women [55.0%]) and 281 patients were enrolled. Patients had a mean (SD) age of 50.6 (11.5) years and included 221 men (78.6%). The mean (SD) body mass index at baseline was 33.4 (5.1). At 12 months, the adjusted mean (SE) weight change was -2.51 (0.73) kg in the peer coaching arm and -0.79 (0.48) kg in the EUC arm, but the difference was not statistically signficant (difference, -1.72 [0.88] kg; P = .05). At 6 months, the adjusted mean (SE) proportion of patients who lost at least 5% of body weight was 16.68% (0.47%) in the peer coaching arm vs 5.50% (0.32%) in the EUC arm (difference, 11.18 [5.22] percentage points; P = .03). At 6 months, the adjusted mean (SE) proportion of patients who attended a weight management program was 28.68% (5.37%) in the peer coaching arm and 13.32% (3.38%) in the EUC arm (difference, 15.37 [6.45] percentage points; P = .02). Conclusions and Relevance: In this randomized clinical trial, a low- to moderate-intensity peer-coaching intervention did not result in greater weight loss at 12 months, but it improved attendance at weight management programs. Trial Registration: ClinicalTrials.gov Identifier: NCT03163264.