Flu is not responsible for all ‘flu and pneumonia’ deaths

Flu is behind 1 in 10 deaths

A headline in the print edition of the Daily Mirror on Wednesday claimed that influenza, or flu, was the cause of nearly 1 in 10 deaths at the start of 2023.

This is almost certainly not correct, and misleadingly describes what the official figures mean.

In total, 1,383 deaths were registered in England and Wales in the week ending 6 January 2023 with an underlying cause in the “Influenza and pneumonia” category in the International Classification of Diseases.

This does account for about 9% of the 14,983 deaths registered that week, which is about 1 in 11 of them. However, these are deaths with an underlying cause of either flu or pneumonia, or sometimes both, which means it isn’t right to suggest that flu itself was involved in all of them.

The Mirror’s article went on to say “flu and pneumonia caused nearly 1 in 10 of all deaths at the start of the year” which, combined with the headline, could wrongly suggest that all these deaths involved flu.

We don’t know how many of the 1,383 deaths had an underlying cause of flu. But, since 2013, deaths registered with flu as the underlying cause have never been more than about 6% of all flu and pneumonia deaths in a given year, although they might make up a larger share in shorter periods.

One caveat with this data is that it is possible that flu is involved in many deaths where it is not recorded. Indeed it is widely thought that flu is an underreported cause of death.

The pathogen that caused the pneumonia is often not identified on death certificates.

This data is also about deaths with an “underlying cause” of flu and/or pneumonia. Doctors can mention more than one cause of death on a death certificate, but only one underlying cause, so it is possible that flu was a contributing factor in some of the pneumonia deaths—especially because there was a large number of flu infections in the last weeks of 2022.

The total number of deaths “involving influenza and pneumonia” in the same week—meaning that at least one of the conditions was mentioned somewhere on the death certificate—was 3,563.

The Office for National Statistics (ONS), which publishes the data on which the Mirror article was based, confirmed to Full Fact that “flu and pneumonia” deaths involve at least one of the conditions, but not necessarily both.

We have written before about media confusion on this issue, after which the ONS clarified its reports.

The Daily Mirror was approached for comment.

Image courtesy of Brittany Colette