Comparing Synchronous and Asynchronous Remotely Delivered Lifestyle Interventions: Protocol for a Randomized Noninferiority Trial.

Background: Remotely delivered lifestyle interventions have emerged to increase the reach and accessibility of traditional interventions that involve numerous in-person visits. Remote interventions can be delivered synchronously via videoconference software or phone or asynchronously via online platforms. Asynchronously delivered interventions are convenient and flexible in that they allow people to participate at any time and as such, they may be more sustainable. Evidence for asynchronous interventions is needed given their potential for convenience and sustainability, which may have implications for weight loss maintenance.

Objective: This is a randomized noninferiority trial comparing 2 remotely delivered lifestyle interventions: one that is delivered synchronously via videoconference meetings and one that is delivered asynchronously through private Facebook (Meta) groups. We hypothesize that the percent weight loss difference between conditions at 6 and 12 months will be less than 2% and that the asynchronous condition will cost less to deliver per pound lost. We also hypothesize that engagement will be higher in the asynchronous condition at 12, 18, and 24 months and that the asynchronous condition will have greater weight loss at 24 months.

Methods: We will randomize 328 participants with overweight or obesity to a remotely delivered lifestyle intervention that is delivered either synchronously or asynchronously. Delivery of the synchronous lifestyle intervention will be via videoconference group sessions, whereas the delivery of the asynchronous lifestyle intervention will be via private Facebook groups. The lifestyle intervention in both conditions is based on the Diabetes Prevention Program. The intervention goals are to lose 5%-10% of baseline weight and to work toward 300 minutes per week of moderate intensity physical activity. The core intervention will last for 12 months and be led by counselors in each group. This will be followed by a 12-month maintenance phase to be led by participant volunteers from each group. Participant engagement and weight loss maintenance will be assessed during this phase. The primary outcome is mean percent weight loss at 6 and 12 months. The noninferiority margin for differences in weight loss between conditions is 2% at both 6 and 12 months. We will model percent weight loss at 6 and 12 months using general linear regression models with the intent-to-treat sample. Secondary outcomes include engagement, collective efficacy, cost, and weight loss at 18 and 24 months.

Results: The funding period began on August 17, 2023, and the study was approved by the University of Connecticut Institutional Review Board on August 17, 2023. Participant recruitment will begin December 2024 and the intervention will begin February 2024.

Conclusions: If hypotheses are confirmed, this work will provide evidence that asynchronously delivered remote interventions are as efficacious as synchronously delivered ones and more sustainable such that people will engage in them longer and retain more weight loss for less cost.

Trial Registration: ClinicalTrials.gov NCT06393725; https://tinyurl.com/4kzzwkc9.

International Registered Report Identifier (irrid): PRR1-10.2196/65323.