Monday, April 13, 2020

Comparing Covid-19 spread globally

There is an ongoing debate on how to compare the spread of the SARS-CoV-2 virus and the victims of the Covid-19 disease among countries.
Several factors affect how this can —or can't— be measured:
  • Countries with early cases of Covid-19 did not initially have the know-how they developed later, which countries with later cases benefited from
  • There are vast differences in the way cases are measured among different countries; therefore cases are not a good measure
  • Those hospitalised, in need of an intensive care unit and dead are accurately measured and comparable with other countries'
  • Measures against the coronavirus differ among different countries, also depending on when the first carriers appeared
    The measures are difficult to account for, but the spread after the same number of day since the first case for each country is somewhat comparable
  • Living conditions and population density also matter and differ among countries
So, which is the right way to compare, by cases, cases per population, cases per population density or cases per country area?
My personal preference is cases by population density, but, for this post, I calculated all three indices for the case of deaths, which you may see in the following interactive charts, using Covid-19 data from the Johns Hopkins University Center for Systems Science and Engineering (JHU CSSE) and country data from Worldometer (please note that, due to name differences in different datasets, not all countries will have their indices calculated yet).

[Update April 27, 2020] The following is a bar chart race of the same data:
Please share your thoughts and/or suggest other types of comparisons in the comments.


This was first posted on April 13, 2020 in the blog "On Anything and Everything" as "Comparing Covid-19 spread globally".