Adherence to micronutrient powder for home fortification of foods among infants and toddlers in rural China: a structural equation modeling approach

BACKGROUND: The WHO recommends daily use of micronutrient powder for infants and toddlers at risk of micronutrient deficiencies in low-and-middle-income countries. China has established a micronutrient powder distribution program in many rural townships and villages, yet adherence to micronutrient powder remains suboptimal; a little is known about the behavioral inputs that may influence adherence. This study examines direct and indirect behavioral inputs in micronutrient powder adherence among caregivers in rural western China following the Integrated Behavioral Model (IBM) framework. METHODS: Cross-sectional data were collected from April to May 2019 among 958 caregivers of children aged 6 to 24 months in six counties. Data were collected on micronutrient powder adherence behavior, direct behavioral inputs (knowledge and skills, intention, salience, environmental constraints, and habits), and indirect behavioral inputs (attitudes, perceived social norms, and personal agency). Structural equation modeling (SEM) adjusted for sociodemographic covariates was used to evaluate the IBM framework. RESULTS: Mean micronutrient powder adherence in the previous seven days was 53.02%, and only 22.86% of caregivers consistently fed micronutrient powder from the start of micronutrient powder distribution at six months of age. The SEM model revealed small- to medium-sized effects of salience (β = 0.440, P < 0.001), intention (β = 0.374, P < 0.001), knowledge and skills (β = 0.214, P < 0.001), personal agency (st. effect = 0.172, P < 0.001), environmental constraints (β=-0.142, P < 0.001), and caregiver generation (β = 0.119, P < 0.05) on micronutrient powder adherence. Overall, 54.7% of the variance in micronutrient powder adherence was explained by the IBM framework. Salience had the largest impact on micronutrient powder adherence (Cohen’s f (2) = 0.227). Compared to parent caregivers, grandparents had a higher degree of micronutrient powder adherence on average (P < 0.001), and behavioral inputs were consistent among both parent and grandparent caregivers. CONCLUSION: There is a need to improve micronutrient powder adherence among rural caregivers. The IBM framework showed a high degree of explanatory power in predicting micronutrient powder adherence behavior. The findings suggest that increased reminders from doctors regarding micronutrient powder and coaching to improve personal agency in micronutrient powder feeding may increase adherence. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12889-022-14731-3.