The effect of access to safe Water, Sanitation, and Hygiene (WASH) facilities on Child Growth Failure among children 6/59 months in Ecuador applying a random intercept multilevel model using cross-sectional ENSANUT 2018 data.

Background: Child Growth Failure - measured as stunting, wasting and underweight - is still an important public health issue affecting 23.1% of children. Typically, literature focused on unproper dietary habits, but living in an unhealthy environment unable to prevent pathogens is another fundamental cause. Objective: To estimate the association between access to safe water, sanitation, and hygiene (WASH) facilities and risk for Child Growth Failure in under-5 children in Ecuador Design: Cross-sectional multilevel study using the Ecuadorian National Survey on Health and Nutrition (ENSANUT) 2018. Participants: 17,688 children 6/59 months residing in 15,382 households. Main outcome measures: Association between the access to safely managed WASH factors and the probability of suffering from: a) stunting, b) underweight and c) wasting; controlling for child's sex, child's age, antenatal care visits, pre-term delivery, assumption of micronutrient during the pregnancy, mother's age, mother's education, mother's height, mother's ethnic group, area and region of residence, the number of people living at home and the family per capita income. The final model is a two-levels random intercept logistic regression focused on the risk of suffering from stunting and underweight. Multilevel logistic models were applied for both the unadjusted and the adjusted estimates. The average marginal effects with the 95% confidence interval and p-value are estimated. Results: A safely managed sanitation system showed the strongest protective effect on underweight (-38.1%, 95% CI -16.9% and -59.4%) and stunting (-14.9%, 95% CI -4.7% and -25.1%). Important protective effects against stunting are observed also thanks to safely managed drinking water (-10.9%, 95% CI -0.1% and -21.6%) and applying proper hygiene habits (-9.5%, 95% CI -0.1% and -19.0%). A potential protective effect on underweight was observed also for proper hygiene habits although a wide confidence interval. No effect was observed between safely managed drinking water and the risk of being underweight. Women are characterized by an important lower risk for both stunting and underweight. Stunting is lower after the 24th month of life while no change is observed for underweight. Pre-term deliveries showed a strong growth of the risk for both stunting and underweight, while antenatal care visits significantly reduced the risk of both stunting and underweight as a high mother's education. Genetical (mother's height) and cultural (mother's ethnic group) aspects play an important role with the highest risk for stunting among Indigenous (+32.5%, 95% CI 19.6%-45.4%) and the lowest among Afro-Ecuadorian children (-20.7%, 95% CI 2.0% and -43.4%). Each additional centimetre of the mother's height from the average value (154.2 cm) reduces the risk for the child of suffering from both stunting (-6.1%, 95% CI -5.3% and -6.7%) and underweight (-5.1%, 95% CI -3.7% and -6.5%). Conclusions: WASH factors play a fundamental role to prevent undernutrition, especially chronic undernutrition (stunting). The study found potential biases due to the use of self-reported cross-sectional data. No data on dietary habits were available for this study which is a potential lack to be considered for the future. Key words: Water, Sanitation, Hygiene, WASH, stunting, underweight, Ecuador.