Infant-level and child-level predictors of mortality in low-resource settings: the WHO Child Mortality Risk Stratification Multi-Country Pooled Cohort

BACKGROUND: Despite impressive reductions in overall global child mortality, the rate of decline has slowed during the past decade. Current guidelines for the care of paediatric patients in low-resource settings mostly focus on broad clinical syndromes or undernutrition rather than children's individual contextualised risk. We aimed to identify readily assessable child-level characteristics that can predict mortality risk in a range of community and health-care settings in high-burden settings. METHODS: The WHO Child Mortality Risk Stratification Multi-Country Pooled Cohort (WHO-CMRS) included pooled data from individual children enrolled in observational or randomised controlled trials in low-income and middle-income countries. The criteria for inclusion of a dataset were documentation of age, weight, vital status, and date of death, and at least two observations per participant younger than 60 months. To calculate odds ratios, we built generalised linear mixed effects regression (glmer) models with each child and each study as random intercepts and time interval as the offset. In all analyses, the outcome was defined as death within the respective observation period of the child. From the glmer models, we predicted absolute risk of death per child-month associated with risk exposures separately and combined with anthropometry according to the following age groups: 0-5 months, 6-11 months, 12-23 months, and 24-59 months. Studies were grouped according to population types studied: the general population, populations selected based on anthropometric criteria, and populations selected based on the presence of illness. FINDINGS: We analysed pooled data from WHO-CMRS, including 75 287 children from 33 studies done in 17 countries between Jan 1, 2001, and Dec 31, 2021. During a total of 69 085 child-years of follow-up, 2805 (3·7%) children died. Age younger than 24 months, low anthropometry, preterm birth, low birthweight, and absence of breastfeeding (either was breastfeeding not offered or an underlying illness ...