Woldehanna Tassew, Behrman Jere R, Araya Mesele W
Department of Economics, Addis Ababa University, Ethiopia.
University of Pennsylvania, Philadelphia, PA, USA.
Ethiop J Health Dev. 2017;31(2):75-84.
There is little empirical evidence on the effect of childhood malnutrition on children's cognitive achievements in low income countries like Ethiopia. A longitudinal data is thus vital to understand the factors that influence cognitive development of children over time, particularly how early childhood stunting affects cognitive achievement of children up to the age of 8 years.
To examine the effect of early childhood stunting on cognitive achievements of children using longitudinal data that incorporate anthropometric measurements and results of cognitive achievement tests such as Peabody Picture Vocabulary Test and Cognitive Development Assessment quantitative tests.
Defining stunted children as those having a standardized height for age z-score less than -2; we used a Propensity Score Matching (PSM) to examine the effect of early childhood stunting on measures of cognitive performance of children. The balance of the propensity score matching techniques was checked and found to be satisfied (P<0.01).
Early childhood stunting is significantly negatively associated with cognitive performance of children. Controlled for confounding variables such as length of breastfeeding, relative size of the child at birth, health problems of early childhood such as acute respiratory illness and malaria, baseline household wealth, child gender, household size and parental education, estimates from PSM show that stunted children scored 16.1% less in the Peabody Picture Vocabulary Test and 48.8% less in the Quantitative Assessment test at the age of eight, both statistically significant at P<0.01.
It is important to realize the importance of early investment in terms of child health and nutrition until five years for the cognitive performance of children. As household wealth and parental education are particularly found to play an important role in children's nutritional achievements, policy measures that are directed in improving household's livelihood may have a spill-over impact in improving child nutritional status, and consequently cognitive development and schooling.
在像埃塞俄比亚这样的低收入国家，关于儿童营养不良对儿童认知成就影响的实证证据很少。因此，纵向数据对于了解随时间影响儿童认知发展的因素至关重要，特别是幼儿发育迟缓如何影响8岁以下儿童的认知成就。
使用包含人体测量数据以及皮博迪图片词汇测试和认知发展评估定量测试等认知成就测试结果的纵向数据，研究幼儿发育迟缓对儿童认知成就的影响。
将发育迟缓儿童定义为年龄标准化身高z分数小于-2的儿童；我们使用倾向得分匹配法（PSM）来研究幼儿发育迟缓对儿童认知表现指标的影响。检查了倾向得分匹配技术的平衡性，发现其得到满足（P<0.01）。
幼儿发育迟缓与儿童的认知表现显著负相关。在控制了母乳喂养时长、出生时儿童相对大小、幼儿期健康问题（如急性呼吸道疾病和疟疾）、基线家庭财富、儿童性别、家庭规模和父母教育程度等混杂变量后，倾向得分匹配法的估计结果显示，发育迟缓儿童在8岁时的皮博迪图片词汇测试中得分低16.1%，在定量评估测试中得分低48.8%，两者在P<0.01水平上均具有统计学意义。
认识到在儿童5岁前对其健康和营养进行早期投资对儿童认知表现的重要性很重要。由于特别发现家庭财富和父母教育在儿童营养成就方面发挥重要作用，旨在改善家庭生计的政策措施可能会对改善儿童营养状况产生溢出效应，从而对认知发展和学业产生影响。
