Global Pattern and Disease Heterogeneity Drivers in Aging Populations

The unprecedented demographic shifts toward an aging population pose significant challenges to global healthcare systems. Understanding the heterogeneity in disease prevalence among the elderly is crucial for effective public health strategies. Using prevalence data of 85 types of age-related diseases, we calculated the global heterogeneity of disease distribution by the Shannon Diversity Index (SHDI). We observed significant geographic variations in disease heterogeneity, with higher SHDI values in high-income Western countries such as the United States of America and Sweden and lower in South Asia and Oceania (p < 0.05). In 2021, SHDI values in elderly populations (age ≥60 years) for Europe and North America countries were an average of 1.12 times higher than in Oceania. While SHDI increases toward higher ages (for instance, in 2021, SHDI for adults above 95 years is 1.06 times higher than for ages between 60 and 64 years), the global SHDI tends to decrease nonlinearly over time. From 1990 to 2021, global age-standardized SHDI (age ≥60 years) averagely decreased by 1.2% for both men and women. Our analysis further revealed that socio-economic factors (e.g., socio-demographic indices, governance) strongly impacted global SHDI changes, while climatic and environmental factors (e.g., extreme climate and air pollution) showed significant differences across genders. Our study highlights the need for implementing comprehensive healthcare strategies, focusing on reducing health disparities and addressing environmental and socio-economic determinants to address inequalities in age-related diseases effectively.