Pragmatic online obesity treatment in primary care: a hybrid randomized clinical trial of implementation strategies

Online behavioral weight loss (BWL) in primary care is effective and disseminable. This trial compared two implementation approaches on program uptake, use, and weight loss via a pragmatic hybrid type 2 implementation-effectiveness design to evaluate online BWL implementation (Rx Weight Loss [RxWL]) and effectiveness. This manuscript presents the implementation results. RxWL was implemented across a state-wide network of primary care clinics using lower- and higher-intensity implementation strategies (Basic [base program] and Enhanced [base plus enhanced training and dashboard], respectively) between 2018 and 2022. Nurse care managers (NCMs; N = 23) were recruited and block-randomized to implementation condition. Adult primary care patients (body mass index [BMI] > 25 kg/m², internet-connected device access) were referred and enrolled by their NCMs. Outcomes were the proportion of eligible patients who enrolled in and completed RxWL by NCM condition, initial weight loss and regain over 12 and 24 months by NCM condition, and clinician acceptability and feasibility. NCMs (N = 12 Enhanced, N = 11 Basic) in Enhanced enrolled more patients (N = 490) than in Basic (N = 164). Although the proportion of patients who completed RxWL and mean weight loss did not differ by condition, different enrollment rates resulted in the Enhanced condition engaging more patients. NCMs rated RxWL as acceptable and feasible with no difference by condition. Findings support connecting primary care patients with technology-based health behavior change programs. Clinical trial registration number: ClinicalTrials.Gov identifier NCT03488212: https://clinicaltrials.gov/ct2/show/NCT03488212 . Trial registration: clinicaltrials.gov Identifier: https://clinicaltrials.gov/study/NCT03488212 .