Estimation of potential global pandemic influenza mortality on the basis of vital registry data from the 1918-20 pandemic: a quantitative analysis

Lancet. 2006 Dec 23;368(9554):2211-8. doi: 10.1016/S0140-6736(06)69895-4.


Background: The threat of an avian influenza pandemic is causing widespread public concern and health policy response, especially in high-income countries. Our aim was to use high-quality vital registration data gathered during the 1918-20 pandemic to estimate global mortality should such a pandemic occur today.

Methods: We identified all countries with high-quality vital registration data for the 1918-20 pandemic and used these data to calculate excess mortality. We developed ordinary least squares regression models that related excess mortality to per-head income and absolute latitude and used these models to estimate mortality had there been an influenza pandemic in 2004.

Findings: Excess mortality data show that, even in 1918-20, population mortality varied over 30-fold across countries. Per-head income explained a large fraction of this variation in mortality. Extrapolation of 1918-20 mortality rates to the worldwide population of 2004 indicates that an estimated 62 million people (10th-90th percentile range 51 million-81 million) would be killed by a similar influenza pandemic; 96% (95% CI 95-98) of these deaths would occur in the developing world. If this mortality were concentrated in a single year, it would increase global mortality by 114%.

Interpretation: This analysis of the empirical record of the 1918-20 pandemic provides a plausible upper bound on pandemic mortality. Most deaths will occur in poor countries--ie, in societies whose scarce health resources are already stretched by existing health priorities.

Publication types

  • Historical Article
  • Research Support, N.I.H., Extramural

MeSH terms

  • Age Distribution
  • Disease Outbreaks / history*
  • Disease Outbreaks / statistics & numerical data
  • Female
  • History, 20th Century
  • Humans
  • Influenza, Human / epidemiology
  • Influenza, Human / history*
  • Influenza, Human / mortality
  • Male
  • Registries
  • Regression Analysis