Investigating the Role of Social Determinants in Child Mortality and Life Expectancy: Longitudinal Analysis of 200 Countries from 1990 to 2021

Longitudinal studies on the social determinants of health (SDH) from a global perspective, including developing countries, are still scarce. This study aimed to examine the associations between major SDH, the child mortality rate (CMR), and life expectancy (LE) according to socioeconomic status (SES), physical environment, health-related behaviors, and healthcare services. Data from 200 countries from 1990 to 2021 were included. The associations between CMR, LE, and SDH were analyzed using fixed-effect regression, and sub-group analyses by high income (HI) and non-HI countries for all analyses. CMR and LE were on the decline, but gaps persisted between HI and non-HI countries. Large intra-group gaps existed in CMR in non-HI countries. Education correlated negatively with CMR in both HI and non-HI countries and positively with LE only in non-HI countries (coef.=0.069, p < 0.0001). Unsafe water correlated positively with CMR and negatively with LE in both HI and non-HI countries. Medical doctors correlated negatively with CMR in both HI and non-HI countries and positively with LE in non-HI countries only (coef.=0.010, p < 0.01). Associations between health status and other SDH were not consistent between HI and non-HI countries. We found differences in major SDH between HI and non-HI countries. However, higher educational levels, safe water guarantee, and number of physicians were key SDH linked to better health status in both HI and non-HI countries. Other SDH should be examined differentially for HI and non-HI countries. Lastly, vaccine coverage was not a strong predictor of national-level health status indicators.