Effect of an Online Weight Management Program Integrated With Population Health Management on Weight Change: A Randomized Clinical Trial

IMPORTANCE: Online programs may help with weight loss but have not been widely implemented in routine primary care. OBJECTIVE: To compare the effectiveness of a combined intervention, including an online weight management program plus population health management, with the online program only and with usual care. DESIGN, SETTING, AND PARTICIPANTS: Cluster randomized trial with enrollment from July 19, 2016, through August 10, 2017, at 15 primary care practices in the US. Eligible participants had a scheduled primary care visit and were aged 20 to 70 years, had a body mass index between 27 and less than 40, and had a diagnosis of hypertension or type 2 diabetes. Follow-up ended on May 8, 2019. INTERVENTIONS: Participants in the usual care group (n = 326) were mailed general information about weight management. Participants in the online program only group (n = 216) and the combined intervention group (n = 298) were registered for the online program. The participants in the combined intervention group also received weight-related population health management, which included additional support from nonclinical staff who monitored their progress in the online program and conducted periodic outreach. MAIN OUTCOMES AND MEASURES: The primary outcome was weight change at 12 months based on measured weights recorded in the electronic health record. Weight change at 18 months was a secondary outcome. RESULTS: Among the 840 participants who enrolled (mean age, 59.3 years [SD, 8.6 years]; 60% female; 76.8% White), 732 (87.1%) had a recorded weight at 12 months and the missing weights for the remaining participants were imputed. There was a significant difference in weight change at 12 months by group with a mean weight change of –1.2 kg (95% CI, –2.1 to –0.3 kg) in the usual care group, –1.9 kg (95% CI, –2.6 to –1.1 kg) in the online program only group, and –3.1 kg (95% CI, –3.7 to –2.5 kg) in the combined intervention group (P