Global childhood diarrhoea prevalence and its determinants: a systematic meta-analytic assessment, 1985-2024.

Background: Childhood diarrhoea is a major contributor to morbidity and mortality among children under five years of age. This study provides an analysis of global childhood diarrhoea prevalence, drawing on standardised, nationally representative survey data collected from 1985 to 2024.

Methods: A systematic review of Demographic and Health Surveys and Multiple Indicator Cluster Surveys conducted up to October 30, 2024, was undertaken, with findings reported in accordance with PRISMA guidelines. Random-effects meta-analyses and meta-regression analyses were conducted. Factor analysis was employed to construct a Socioeconomic and Child Nutrition Index, integrating socioeconomic, water, sanitation, hygiene, and nutrition indicators.

Findings: The analysis identified 593 relevant studies, estimating a global pooled mean childhood diarrhoea prevalence of 14.4% (95% CI: 13.8-15.0%) across all regions and time periods. Prevalence declined at a rate of 1% per year, falling from 22.3% in 1985-1989 to 10.9% in 2020-2024, with consistent declines observed in all regions except the Eastern Mediterranean Region. Prevalence was highest in the African Region and lowest in the European Region. Higher prevalence was observed in countries with larger household sizes, longer water collection times, and higher rates of underweight, stunting, and wasting. In contrast, lower prevalence was associated with higher levels of urbanisation, maternal education, population density, Human Development Index, income per capita, and access to improved water sources and sanitation facilities. A higher Socioeconomic and Child Nutrition Index was strongly and consistently associated with lower diarrhoea prevalence, demonstrating a dose-response relationship.

Interpretation: Childhood diarrhoea prevalence has declined over recent decades, apparently reflecting the synergistic effects of targeted public health interventions and broader socioeconomic progress in addressing upstream determinants of child health.

Funding: This work was supported by the Biostatistics, Epidemiology, and Biomathematics Research Core at Weill Cornell Medicine-Qatar. The statements made herein are solely the responsibility of the authors.