Income inequality and the disease burden of COVID-19: Survival analysis of data from 74 countries.

The COVID-19 pandemic presents a rare opportunity to assess national performance in responding to a historic crisis. It is not well understood how income inequality might be related to differential disease burden of COVID-19 across countries. Using recent data merged from Our World in Data 2020, the World Bank, and the Global Burden of Disease, we examined the association between income inequality (the Gini index) and COVID-19 infection and death rates among 74 countries with available data. After adjusting for differences in population size, age structure, longevity, population density, GDP per capita, health care expenditures, educational attainment, direct democracy index, stringency of implemented measures, and testing intensity for COVID-19, results from Cox Proportional Hazards regressions revealed that countries with more unequal income distribution carried a higher burden of COVID-19 infections and deaths in 2020. On average, each percentage point increase in the Gini index was associated with an 9% increase in the hazard of having a higher COVID-19 infection rate in the sample (AOR = 1.09, 95% CI 1.01, 1.18). The corresponding associated increase in the hazard of having a higher COVID-19 death rate was 14% (AOR = 1.14, 95% CI 1.06, 1.23). Countries with severe and persistent income inequality should develop national strategies to address this challenge to be better prepared for future pandemics.