Inequalities in stunting among under-five children in Tanzania: Decomposing the Concentration Indexes using Demographic Health Surveys from 2004/5 to 2015/6

Abstract

Background: Child stunting is a global health concern. Stunting leads to several consequences on child survival, growth, and development. The absolute level of stunting has been decreasing in Tanzania although the prevalence is still high (34%), varying across socioeconomic determinants with a larger burden among the disadvantaged group. The reduction of inequalities in stunting is very crucial as we aim to reduce stunting to 28% by 2021 and hence attain zero malnutrition by 2030 under Sustainable Development Goal 2.2.. Objectives: This study aimed to determine the trend, contributing factors and changes of inequalities in stunting among children aged 3 – 59 months from 2004 to 2016 Methodology: Data were drawn from the Tanzania Demographic and Health Surveys. The dependent variable was stunting. The concentration index was used to quantify the magnitude of inequalities in stunting for each year. To get the contribution of each determinant on the inequality in stunting, the concentration index was decomposed by using the Wagstaff and Watanabe decomposition methods of the concentration index. Results: Inequalities in stunting insignificantly declined from -0.019 (p<0.001) in 2004 to -0.018 (p<0.001) in 2010 and then to -0.0096 (p<0.001). Disparities in the distribution of wealth index (mean contribution > 84.7%) and maternal years of schooling (mean contribution > 22.4%) increased the levels of inequalities in stunting in all survey years. Rural-urban differences reduced inequalities in stunting although the contribution changed over time. Conclusion: Inequalities in stunting declined, differentials in wealth index and maternal education had increased contribution to the levels of inequalities in stunting. To significantly reduce the larger burden of stunting among the disadvantaged groups, initiatives should be embarked on the distribution of social services including maternal and reproductive education among women of reproductive age, water and health infrastructures in local areas.