Why Covid is at least 10 times more deadly than the flu

Rod Jackson in the New Zealand Herald:

Estimates of the proportion of people who die from Covid-19 have been controversial, with some even dismissing it as similar to a bad flu. There are three main problems accounting for this controversy.

In this article, I describe each of these problems and some of the ways that epidemiologists such as me me try to deal with them.

Problem 1: To calculate the proportion of people who have been infected with Covid-19 and who die as a result (the Infection Fatality Proportion), you need two numbers – the number of deaths (the numerator) and the number of people who have been infected (the denominator) and then you divide the numerator by the denominator.

It sounds simple, but unfortunately accurate information on both these numbers for Covid-19 is hard to find, unless you know what to look for. Just for the record, I have used the correct epidemiological term – the “Infection Fatality Proportion” not the “Infection Fatality Rate” – because it’s not actually a rate. In epidemiology, a rate requires a time component, for example, 10 deaths per 1000 people per year.

More here.