Weight gain prevention outcomes from a digital health pragmatic randomized controlled trial with community health center patients.

BACKGROUND:The prevalence of obesity and its associated comorbidities continues to rise in the United States. Populations who are uninsured and from racial and ethnic minority groups continue to be disproportionately affected. These populations also experience fewer clinically meaningful outcomes in most weight loss trials. Weight gain prevention presents a useful strategy for individuals who experience barriers to weight loss. Given the often-limited weight management resources available to patients in primary care settings serving vulnerable patients, evaluating interventions with pragmatic designs may help inform the design of comprehensive obesity care delivered in primary care. OBJECTIVE:To evaluate the effectiveness of Balance, a two-arm 12-month pragmatic randomized controlled trial of a digital weight gain prevention intervention, delivered to patients receiving primary care within Federally qualified community health centers (FQHCs). METHODS:Balance was a two-arm 12-month pragmatic randomized controlled trial of a digital weight gain prevention intervention delivered to individuals who had a body mass index (BMI) of 25-40 kg/m2, spoke English or Spanish, and were receiving primary care within a network of FQHCs in North Carolina. The Balance intervention was designed to encourage behavioral changes that result in a slight energy deficit. Intervention participants received: tailored goal setting and tracking, skills training, self-monitoring, and responsive health coaching from registered dietitians. Weight was measured at regular primary care visits and documented in the electronic health record. We compared the percentage of ≤ 3% weight gain in each arm at 24-months post-randomization, our primary outcome, using individual empirical best linear unbiased predictors (EBLUPs) from linear mixed effects model. We used individual EBLUPs from participants with at least one electronic health record (EHR) weight documented within a 6-month window centered on the 24-month time point. RESULTS:We randomized 443 participants, 223 of which were allocated to the intervention arm. At baseline, participants had a mean BMI of 32.6. Most participants were Latino/Hispanic (45.1%) or non-Latino/Hispanic White (26.0%). Fifty-three percent of participants had at least one visit with weight measured in the primary time window. The intervention group had a higher proportion with ≤3% weight gain at 6 months (risk ratio=1.12; 95% CI 0.94, 1.28; risk difference=9.5pp; 95% CI -4.5, 16.4). This difference attenuated to the null by 24 months (risk ratio=1.00; 95% CI 0.82, 1.20; risk difference=0.2pp; 95% CI -12.1, 11.0). CONCLUSIONS:In adults with overweight or obesity receiving primary care at a community health center, we did not find long-term evidence to support the dissemination of a digital health intervention for weight gain prevention. CLINICALTRIAL:Balance: A Pragmatic Trial of a Digital Health Intervention to Prevent Weight Gain in Primary Care (NCT03003403) was registered on ClinicalTrials.gov. INTERNATIONAL REGISTERED REPORT:RR2-10.1186/s12889-019-6926-7.