The statistics site Our world in data shows the number of coronary deaths per million inhabitants in each country, based on the average of confirmed deaths over the past seven days.

On May 20, Sweden had 6.08 deaths per million inhabitants, which is the highest figure in the world during the seven-day period. Then comes the UK with an average of 5.57 deaths.

However, state epidemiologist Anders Tegnell believes that the comparison is difficult and that the Swedish figure must be compared with other aspects.

- On the one hand, deaths per day have been picked, which we know is extremely variable in Sweden. We have deaths that range between four and 140, so that is not a relevant figure to take, and partly that the countries are at completely different stages in the spread of infection, he said during Wednesday's press conference.

- Looking at a week somewhere gives no clue as to who has succeeded more or less well with different measures.

"Very simplified"

Dan Hedlin, professor of statistics at Stockholm University, is of a different opinion.

- Seven days average should be able to even out the weekday effect that you have in Sweden. We also see that the pattern is quite steady from week to week, he says.

He sees other problems with the calculations instead.

- We are used to counting on averages in all possible contexts, but they are really very abstract. What is so striking about covid-19 is how large the regional differences are in all countries. Drawing an average for the whole country then is very simplistic, he says.

Different methods in different countries

The fact that case reporting and testing looks different in different countries also affects the result. In some countries, such as the United Kingdom, only deaths that occurred in hospitals are reported and not those that occur in elderly care.

- It is not so easy to compare the number of dead because the countries count in different ways. In addition, the deaths have not necessarily been reported on the same day as they occurred, leading to a backlog in the statistics, says Dan Hedlin.

The statistics are based on figures from the EU's infection control unit ECDC and have been compiled by the University of Oxford.