Global Health Indicators and Child Mortality Trends: Insights from a Global Panel Data Analysis of 200 Countries

The aim of this study was to explore how medical resources and vaccine coverage relate to infant mortality rate (IMR) and under-five mortality rate (U-5MR), which are both key national health indicators. This longitudinal study was based on panel data from the national level of 200 countries. Data from 1990 to 2021 were grouped into seven regions based on geographic and epidemiological similarities. Regarding correlation, the high-income region showed a different trend from that shown by other regions. Health expenditure was positively associated with IMR and U-5MR globally. Number of medical doctors per 1,000 people was negatively associated with IMR and U-5MR globally. Hepatitis type B (HBV) and measles, first dose (MCV) were negatively associated with IMR and HBV, MCV, and Bacillus Calmette-Guérin were negatively associated with U-5MR globally. In quadratic regression, the correlation between the number of doctors and mortality stabilizes or plateaus at approximately four individuals. Overall vaccine coverage was positively correlated with mortality up to a certain threshold, beyond which it became negatively correlated. A higher number of doctors was consistently associated with decreased mortality, regardless of location, while other factors varied by region. Our study findings highlight the importance of implementing global strategies that are specific to each region's characteristics to reduce IMR and U-5MR.