Early Childhood Developmental Status in Low- and Middle-Income Countries: National, Regional, and Global Prevalence Estimates Using Predictive Modeling

Abstract

Background: The development of cognitive and socioemotional skills early in life influences later health and well-being. Existing estimates of unmet developmental potential in low- and middle-income countries (LMICs) are based on either measures of physical growth or proxy measures such as poverty. In this paper we aim to directly estimate the number of children in LMICs who would be reported by their caregivers to show low cognitive and/or socioemotional development.

Methods and findings: The present paper uses Early Childhood Development Index (ECDI) data collected between 2005 and 2015 from 99,222 3- and 4-y-old children living in 35 LMICs as part of the Multiple Indicator Cluster Survey (MICS) and Demographic and Health Surveys (DHS) programs. First, we estimate the prevalence of low cognitive and/or socioemotional ECDI scores within our MICS/DHS sample. Next, we test a series of ordinary least squares regression models predicting low ECDI scores across our MICS/DHS sample countries based on country-level data from the Human Development Index (HDI) and the Nutrition Impact Model Study. We use cross-validation to select the model with the best predictive validity. We then apply this model to all LMICs to generate country-level estimates of the prevalence of low ECDI scores globally, as well as confidence intervals around these estimates. In the pooled MICS and DHS sample, 14.6% of children had low ECDI scores in the cognitive domain, 26.2% had low socioemotional scores, and 36.8% performed poorly in either or both domains. Country-level prevalence of low cognitive and/or socioemotional scores on the ECDI was best represented by a model using the HDI as a predictor. Applying this model to all LMICs, we estimate that 80.8 million children ages 3 and 4 y (95% CI 48.1 million, 113.6 million) in LMICs experienced low cognitive and/or socioemotional development in 2010, with the largest number of affected children in sub-Saharan Africa (29.4.1 million; 43.8% of children ages 3 and 4 y), followed by South Asia (27.7 million; 37.7%) and the East Asia and Pacific region (15.1 million; 25.9%). Positive associations were found between low development scores and stunting, poverty, male sex, rural residence, and lack of cognitive stimulation. Additional research using more detailed developmental assessments across a larger number of LMICs is needed to address the limitations of the present study.

Conclusions: The number of children globally failing to reach their developmental potential remains large. Additional research is needed to identify the specific causes of poor developmental outcomes in diverse settings, as well as potential context-specific interventions that might promote children's early cognitive and socioemotional well-being.

Fig 1. Percentage of children scoring low in cognitive and/or socioemotional development on the ECDI by sex (r = −0.04, p < 0.01).

Correlation performed with girls = 1, boys = 0. CAR, Central African Republic; DRC, Democratic Republic of the Congo; Lao, Lao People’s Democratic Republic; Moldova, Republic of Moldova.

Fig 2. Percentage of children scoring low in cognitive and/or socioemotional development on the ECDI by urbanicity (r = 0.07, p < 0.01).

Correlation performed with rural = 1, urban = 0.

Fig 3. Percentage of children scoring low in cognitive and/or socioemotional development on the ECDI by stunting status (r = 0.10, p < 0.01).

Correlation performed with stunted children = 1, non-stunted children = 0.

Fig 4. Percentage of children scoring low in cognitive and/or socioemotional development on the ECDI by wealth quintile (r = −0.03, p < 0.01).

Correlation performed with highest wealth quintile = 1, lowest wealth quintile = 0.

Fig 5. Percentage of children scoring low in cognitive and/or socioemotional development on the ECDI by child age (r = −0.05, p < 0.01).

Correlation performed with children age 4 y = 1, children age 3 y = 0.

Fig 6. Percentage of children scoring low in cognitive and/or socioemotional development on the ECDI by cognitive stimulation (r = 0.06, p < 0.01).

Correlation performed with lowest quintile of cognitive stimulation = 1, highest quintile of cognitive stimulation = 0.

Fig 7. Scatterplots showing country-level relationships between low socioemotional and/or cognitive ECDI score and stunting and HDI.

Proportion of children with low socioemotional and/or cognitive ECDI score relative to the proportion of children with stunting (top) and relative to country HDI (bottom).

Fig 8. Estimated proportion of children with low development per the ECDI by country.

This figure was generated with a shapefile from DIVA-GIS (http://diva-gis.org) using the Open Source Geospatial Foundation’s QGIS package (http://qgis.osgeo.org).