Abstract 009: Microclinic Social Network Lifestyle Intervention for Weight Loss and Obesity Management: A 10-Month Randomized Controlled Trial
Authors: Eric L Ding 1; Marta R Prescott2; Kathleen T Watson2; Nancy Bui2; Leila Makarechi2 ; Daniel E Zoughbie2 1 Harvard Sch of Public Health, Boston, MA 2 Microclinic International, San Francisco, CA
BACKGROUND: Lifestyle behaviors and health conditions, such as obesity, smoking, and alcohol use, are observed to contagiously propagate in social networks. However, to date, such effects have only been evaluated in observational studies; evidence from socially-engineered health programs to directly harness the power of social networks have yet to exist. The Microclinic Social Network program was developed to leverage social network effects, to socially propagate healthy lifestyles for improving disease prevention and management.
METHODS: In a 10-month randomized controlled trial in Bell County, Kentucky, we evaluated the Microclinic Social Network intervention, harnessing pre-existing social cluster connections to influence and propagate change in lifestyle factors for improving obesity in a resource-limited rural area. Microclinics consisted of social clusters of 2-6 individuals who participated together in nutrition, physical activity, health education and social activity sessions weekly with health-educators; controls had access to standard care from local county health department. Body weight, waist circumference, and blood pressure were collected in 4 followup waves. Longitudinal analyses utilized multi-level repeated measures mixed models, with multi -levels of community center and social cluster, with AR1 autoregressive covariance by time, and heteroskedastic variances by intervention group.
RESULTS: Among 265 participants at baseline, 91.5% were women, mean age=51.5 years (SD=13.5), mean BMI=36.2 (7.55), mean baseline waist circumference=43.6 inches (5.77), and mean social cluster size= 4.1 individuals/microclinic. After 10-month program, MSN intervention group showed decreased body weight of -5.32 lbs (95% CI: -8.36 to -2.29) compared to controls (P<0.001). The absolute BMI net change was -0.95 (-1.48 to -0.42), with corresponding percent BMI net change being -2.44% (P<0.001). Furthermore, central adiposity improved substantially, with a waist circumference net change of -1.54 inches (- 2.39 to -0.69; P<0.001). Among morbidly obese (BMI>=35) participants at start of study, the MSN program decreased the likelihood of remaining morbidly obese by the end of the program by -13% (Relative Risk=0.87, 95% CI: 0.76-0.99; P=0.04). Furthermore, MSN participants notably lowered systolic blood pressure by -6.59 mm Hg (-12.7 to -0.48; P=0.03). Multi-level models also revealed network effect of microclinic social clusters to explain 26% of correlated BMI trajectories among intervention participants, versus just 13.1% among social clusters in controls.
CONCLUSIONS: Results indicate that the Microclinic Social Network lifestyle intervention may be effective for weight loss management. As the first randomized trial engineered to directly leverage effects of social networks, findings yield promise for the power of social networks to propagate healthy lifestyle behaviors for public health.