Beyond deaths per capita: comparative COVID-19 mortality indicators

Area of Science:

• Demography
• Epidemiology
• Public Health

Background:

• The COVID-19 pandemic has caused significant mortality globally.
• Accurate comparison of COVID-19 death rates across diverse populations is challenging due to differences in age structure and data availability.

Purpose of the Study:

• To present and evaluate demographic measures for comparing COVID-19 mortality.
• To assess the impact of COVID-19 deaths on life expectancy at birth in 2020.
• To compare the utility of unstandardized, directly standardized, and indirectly standardized rates for international comparisons.

Main Methods:

• Utilized COVID-19 death statistics from 186 countries and subnational regions in Brazil, China, Italy, Mexico, Peru, Spain, and the USA.
• Calculated unstandardized occurrence/exposure rates (Crude Death Rate equivalent).
• Applied indirect age- and sex-standardization to death rates, and calculated reductions in life expectancy at birth.

Main Results:

• New York exhibited the highest unstandardized COVID-19 death rate at its peak.
• Standardization revealed different population rankings: Italy, Spain, and the USA had high unstandardized rates, while Mexico and Peru had high standardized rates.
• US life expectancy declined by over a year (-1.26 years) in 2020, reaching its lowest since 2008. Panama, Peru, Italy, Spain, USA, and especially Mexico experienced even larger life expectancy reductions.

Conclusions:

• Indirect standardization is a practical and valid method for international comparisons of COVID-19 mortality, requiring less data than direct standardization.
• Several populations experienced substantial reductions in life expectancy in 2020 due to COVID-19 deaths, highlighting the pandemic's demographic impact.