Co-Occurrence of Stunting and Off-Track Early Child Development in Low- and Middle-Income Countries.

Importance: Although children across low- and middle-income countries (LMICs) are increasingly surviving, many are not fully thriving. Both stunting and off-track early child development (ECD) hinder children's potential to thrive. Objectives: To estimate the global prevalence of the co-occurrence of stunting and off-track ECD and explore its association with nurturing care and sociodemographic factors. Design, Setting, and Participants: This cross-sectional study pooled data from the most recent Demographic and Health Surveys and Multiple Indicator Cluster Surveys (2010-2020) on 173 416 children aged 36-59 months in 41 LMICs. Statistical analysis was conducted from February to December 2024. Exposure: Risk factors pertaining to inadequate nurturing care, low socioeconomic status, and other sociodemographic characteristics. Main Outcomes and Measures: Children were classified into 4 groups with respect to thriving: children who were stunted only (height-for-age z score <-2 SD), off-track ECD only (measured using the Early Childhood Development Index), both stunted and off-track ECD (co-occurrence), or neither. Results: In the pooled sample of 173 416 children, the mean (SD) child age was 47.1 (6.8) months, and 88 242 (50.9%) were boys. Approximately 1 in 6 children (17.0% [95% CI, 16.8%-17.2%]) were both stunted and had off-track ECD, 17.1% (95% CI, 16.9%-17.3%) were stunted only, 27.8% (95% CI, 27.6%-28.0%) had off-track ECD only, and 38.1% (95% CI, 37.9%-38.4%) were neither stunted nor had off-track ECD. Socioeconomic gradients were observed, with more co-occurrence in lower-income countries (18.2% [95% CI, 17.9%-18.6%]), poorer households (22.1% [95% CI, 21.7%-22.5%] for poorest wealth quintile), mothers with lower educational levels (20.8% [95% CI, 20.6%-21.0%] for primary education or less), and rural settings (19.3% [95% CI, 19.1%-19.6%]). Various indicators of inadequate nurturing care along with low socioeconomic status were associated with co-occurrence. The top 5 factors associated with co-occurrence were poorest wealth quintile (adjusted odds ratio [AOR], 2.75; 95% CI, 2.53-2.99), no early childhood education (AOR, 2.22; 95% CI, 2.10-2.34), low maternal educational level (AOR, 1.44; 95% CI, 1.37-1.51), no toys at home (AOR, 1.43; 95% CI, 1.35-1.51), and diarrhea (AOR, 1.38; 95% CI, 1.31-1.45). The associations of poor household wealth, no birth registration, and no early childhood education with co-occurrence were significantly larger than their associations with stunting only or off-track ECD only. Conclusions and Relevance: This cross-sectional study of young children in LMICs suggests that a significant proportion were both stunted and had off-track ECD. These findings underscore the need for multisectoral interventions that holistically target nutrition, health, and ECD risks to ensure that all children globally can thrive, especially those facing the double burden of stunting and off-track ECD.