Demographic science aids in understanding the spread and fatality rates of COVID-19

Abstract

Governments around the world must rapidly mobilize and make difficult policy decisions to mitigate the coronavirus disease 2019 (COVID-19) pandemic. Because deaths have been concentrated at older ages, we highlight the important role of demography, particularly, how the age structure of a population may help explain differences in fatality rates across countries and how transmission unfolds. We examine the role of age structure in deaths thus far in Italy and South Korea and illustrate how the pandemic could unfold in populations with similar population sizes but different age structures, showing a dramatically higher burden of mortality in countries with older versus younger populations. This powerful interaction of demography and current age-specific mortality for COVID-19 suggests that social distancing and other policies to slow transmission should consider the age composition of local and national contexts as well as intergenerational interactions. We also call for countries to provide case and fatality data disaggregated by age and sex to improve real-time targeted forecasting of hospitalization and critical care needs.

Keywords: COVID-19; age structure; demography; mortality.

Fig. 1.

Population composition (Left) and expected deaths in population (Right) for Italy and Republic of Korea (Top) and Nigeria and Brazil (Bottom). Projections assume 10% population infection rate and current age−sex-specific case fatality rates from Italy (Dataset S1).

Fig. 2.

Expected deaths by total population (Top) and proportion of total population by age group (Bottom) for Italy, United States, and Nigeria, with different levels of population infection and current age-specific fatality rates from Italy.