Health and Inequality in Under-Five Mortality Rates: A Longitudinal Multilevel Analysis in South America (2000-2020)

This study investigates the connection between health and inequality variables, and under-five infant mortality rates in ten South American countries (Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Paraguay, Peru, Venezuela, and Uruguay). For this purpose, we conducted a longitudinal multilevel model where the dependent variable was Under-5 Mortality Rate (U5MR). To address the health factors and inequalities in the study of U5MR, we selected the following indicators: (i) -a- immunization coverage for diphtheria and -b- immunization coverage for measles in children under 1 year old, (ii) prevalence levels of anemia in women of childbearing age, (iii) undernourishment levels in the population, (iv) the percentage of urban population, and (v) the ratio between per capita health expenditure and GDP per capita. We obtained the indicators from three data sources: The World Bank, the World Health Organization, and the Food and Agriculture Organization of the United Nations. The selected variables were measured over 21 time-steps (2000-2020) for the ten South American countries. We compared three hierarchical linear models, finding that the model incorporating time as a predictor provided the best fit for explaining mortality. This model suggests that factors like increased undernourishment and anemia are associated with higher infant mortality, while a higher urban population correlates with lower mortality, alongside a general global decline over time.