Information Diffusion and Social Norms Are Associated with Infant and Young Child Feeding Practices in Bangladesh.

BACKGROUND: Interaction within mothers' social networks can theoretically diffuse messages from interventions and campaigns into norms and practices for infant and young child feeding (IYCF). OBJECTIVES: We hypothesized that mothers' social networks, diffusion of information, and social norms differed in intensive [intensive interpersonal counseling (IPC), community mobilization (CM), and mass media (MM)] compared with nonintensive (standard IPC and less-intensive CM and MM) intervention areas, were associated with IYCF practices, and partly explained practice improvement. METHODS: We conducted household surveys at endline in 2014 and follow-up in 2016 (n = ∼2000 each round). We used multiple regression to test differences and changes in networks, diffusion, and norms within intervention areas. We analyzed paths from intervention exposure to IYCF practices through networks, diffusion, and norms. RESULTS: Mothers' networks were larger in intensive than in nonintensive areas in 2014 and increased in both areas over time [25-38 percentage points (pp)]. The prevalence of receipt of IYCF information was high, with no changes over time in intensive areas but an increase in nonintensive areas (8-16 pp). In both areas, more family members and health workers provided IYCF information over time. Sharing of information increased 17-23 pp in intensive and 11-41 pp in nonintensive areas over time. Perceived descriptive norms improved 8-16 pp in intensive and 17-28 pp in nonintensive areas. Perceived injunctive norms were high in both areas. Breastfeeding practices were associated with networks, diffusion, and norms (OR: 1.6-4.4 times larger comparing highest with lowest quartile). Minimum dietary diversity was associated with larger networks and diffusion (OR: 1.5-2.2) but not with social norms. Indirect paths from intervention exposure to practices explained 34-78% of total effects. CONCLUSIONS: Diffusion of IYCF information through social networks, reinforced by positive social norms for messages promoted over time, will contribute to positive changes in IYCF practices that may be achieved and sustained through large-scale social and behavior change interventions. This trial was registered at clinicaltrials.gov as NCT0274084.