Knowledge for policy
Briefing 4 May 2020

COVID-19 Cases and Case Fatality Rate by age

The report provides a comparison of cases and fatalities of COVID-19 by age and by provinces and regions in some of the most affected countries. The main objective of the comparison is to evaluate possible effects of the demographic characteristics of population on the epidemic outcomes. The analysis is preliminary since it is based on constantly evolving data while the COVID-19 pandemic is still unfolding. Age distributions are presented by large age classes and using estimated values for harmonised 5-year age groups. In addition to Case Fatality Rates, we calculate three main indicators: Synthetic CFR, Relative Illness Ratio and Relative Mortality Ratio. Finally, we examine the relation between the geographical patterns of cases and fatalities and the demographic profiles of the population. The distribution of both cases and fatalities across ages shows several anomalies. However our findings seem to exclude the fact that an older population alone may justify the high number of fatalities recorded in particular in the case of Italy.

Key messages

  • Given the fact that fatalities caused by COVID-19 are mostly concentrated in older age groups who suffer from underlying medical conditions and with considerable differences between males and females, for the management of sanitary response, it is important to avail of harmonised data on cases and fatalities by age and gender.
  • Such data needs to be adjusted considering the underlying differences in age structure.
  • Despite the demographic adjustments, the distribution of both cases and fatalities across ages shows several anomalies. A striking anomaly is in the case of Italy which has a high Case Fatality Rate for ages above 60 years in respect to other countries.
  • The literature points to the fact that differences in age distributions of the Case Fatality Rate may originate from the procedure adopted in each country for testing and reporting positive cases and fatalities attributable to COVID-19 and todemographic factors.
  • In our analysis, when considering fatalities in relative terms across age groups rather than the CFR, we don’t find significant differences between countries, since 94% of fatalities are uniformly concentrated in the population over 60 years of age.
  • A territorial analysis of the distribution of cases and fatalities shows that there are clear geographical patterns in the diffusion of the disease, but these patterns are not related to differences in the share of elderly across provinces and regions.
  • These last two findings seem to exclude the fact that an older population alone may justify the high number of fatalities recorded in particular in the case of Italy.