Geographical variation in case fatality rate and doubling time during the COVID-19 pandemic

A Mazumder1, M Arora1, M S Sra1

  • 1All India Institute of Medical Sciences (AIIMS), New Delhi, India.

Insights

This study introduces a cumulative case fatality rate (cCFR) method for more stable epidemic analysis. It reveals significant international variations in COVID-19 outcomes and epidemic control.

Area of Science:

  • Epidemiology
  • Infectious Disease Dynamics
  • Public Health

Background:

  • Case fatality rate (CFR) and doubling time are critical epidemic metrics.
  • COVID-19 exhibits significant international variability in CFR and doubling time.
  • Traditional CFR calculations are inaccurate early in an epidemic due to unknown outcomes.

Purpose of the Study:

  • To introduce a cumulative case fatality rate (cCFR) for temporal stability.
  • To estimate daily average doubling time for COVID-19.
  • To analyze international variations in CFR and epidemic control.

Main Methods:

  • Calculated cumulative CFR using only patients with known outcomes.
  • Estimated daily average doubling time.
  • Compared cCFR and doubling times across different countries.

Main Results:

  • The cCFR method provides temporally stable fatality rates.
  • Countries like the US, France, Turkey, and China initially had high cCFR.
  • Germany, China, and South Korea showed low cCFR by April 22.
  • China and South Korea demonstrated effective epidemic control with high doubling times.
  • Russia's doubling time remained under 10 days.

Conclusions:

  • The cCFR method offers a more reliable measure of epidemic fatality.
  • Improved outcomes and wider testing strategies influence cCFR stability.
  • Effective epidemic control is linked to high doubling times and reduced cCFR.

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