Zanello Giacomo, Srinivasan C S, Shankar Bhavani
School of Agriculture, Policy and Development, University of Reading, Reading, United Kingdom.
Centre for Development, Environment and Policy, School of Oriental and African Studies, University of London, London, United Kingdom.
PLoS One. 2016 Sep 20;11(9):e0162668. doi: 10.1371/journal.pone.0162668. eCollection 2016.
In many developing countries, high levels of child undernutrition persist alongside rapid economic growth. There is considerable interest in the study of countries that have made rapid progress in child nutrition to uncover the driving forces behind these improvements. Cambodia is often cited as a success case having reduced the incidence of child stunting from 51% to 34% over the period 2000 to 2014. To what extent is this success driven by improvements in the underlying determinants of nutrition, such as wealth and education, ("covariate effects") and to what extent by changes in the strengths of association between these determinants and nutrition outcomes ("coefficient effects")? Using determinants derived from the widely-applied UNICEF framework for the analysis of child nutrition and data from four Demographic and Health Surveys datasets, we apply quantile regression based decomposition methods to quantify the covariate and coefficient effect contributions to this improvement in child nutrition. The method used in the study allows the covariate and coefficient effects to vary across the entire distribution of child nutrition outcomes. There are important differences in the drivers of improvements in child nutrition between severely stunted and moderately stunted children and between rural and urban areas. The translation of improvements in household endowments, characteristics and practices into improvements in child nutrition (the coefficient effects) may be influenced by macroeconomic shocks or other events such as natural calamities or civil disturbance and may vary substantially over different time periods. Our analysis also highlights the need to explicitly examine the contribution of targeted child health and nutrition interventions to improvements in child nutrition in developing countries.
在许多发展中国家，儿童营养不良的高发状况在经济快速增长的同时持续存在。人们对那些在儿童营养方面取得快速进展的国家进行了大量研究，以探寻这些改善背后的驱动因素。柬埔寨常被视为一个成功案例，在2000年至2014年期间，该国儿童发育迟缓发生率从51%降至34%。这种成功在多大程度上是由营养的潜在决定因素（如财富和教育）的改善（“协变量效应”）驱动的，又在多大程度上是由这些决定因素与营养结果之间关联强度的变化（“系数效应”）驱动的？利用源自广泛应用的联合国儿童基金会儿童营养分析框架的决定因素以及来自四个人口与健康调查数据集的数据，我们应用基于分位数回归的分解方法，来量化协变量和系数效应对儿童营养改善的贡献。该研究中使用的方法允许协变量和系数效应在儿童营养结果的整个分布范围内有所不同。在严重发育迟缓和中度发育迟缓儿童之间以及农村和城市地区之间，儿童营养改善的驱动因素存在重要差异。家庭禀赋、特征和做法的改善转化为儿童营养的改善（系数效应）可能会受到宏观经济冲击或其他事件（如自然灾害或内乱）的影响，并且在不同时间段可能会有很大差异。我们的分析还强调了明确审视针对性儿童健康和营养干预措施对发展中国家儿童营养改善贡献的必要性。
