Human settlement environment and childhood diarrhea in low- and middle-income countries.

Multidimensional impacts of human settlement environment (HSE) on childhood diarrhea in low- and middle-income countries (LMICs) remain largely underexplored. Diarrhea data used in this study were collected from the Demographic and Health Surveys Program during 2005-2019. For each location, 65 HSE-related indicators were measured from land-cover product, gridded socioeconomic dataset and other sources, and then classified into five dimensions: living environment, socioeconomic condition, public service, climatic moderation, and landscape ecology. Confirmatory factor analysis was used to construct the dimensions of HSE. Binomial generalized linear mixed-effects models were employed to explore the association between HSE dimensions and risk of childhood diarrhea. A total of 1,340,334 children under five from 53 LMICs were included in this study. All the five dimensions, except for landscape ecology, were negatively associated with childhood diarrhea. For example, compared with the low level, high level of socioeconomic condition was linked to a lower diarrhea risk (OR = 0.671, 95 % CI: 0.643-0.701). Regionally, these associations were particularly evident in Africa and Asia. Stratified analysis revealed that the impacts of living environment and socioeconomic condition dimensions were more pronounced in urban, wealthy, and high-education households, while public service had greater effects in rural, low-income settings. In conclusion, well-planned settlement environments, higher socioeconomic status, high-quality public services, and suitable climatic conditions are associated with mitigated risk of childhood diarrhea. These findings provide valuable insights for developing context-specific interventions.