You asked
With reference to the following statement from April 2020:
"…deaths where COVID-19 was mentioned on the death certificate are kept separate from deaths where the underlying cause was respiratory.
Respiratory and covid-10 (sic.) figures should not be added together"
In stark contrast to that, I note that for many weeks, the weekly published death updates from ONS have been stating the following:
"Note: Deaths could possibly be counted in both causes presented. If a death had an underlying respiratory cause and a mention of COVID-19 then it would appear in both counts."
Please could you advise why and when this change occurred and from what week did it start to take effect (the previously published weekly update data does not appear to have been altered retrospectively.) Presumably around the time of the "second wave", post-July/August?
We said
Thank you for your enquiry.
Due to a difference in the way we report deaths for these cause groups, it is possible that some deaths are counted in both the respiratory and COVID-19 categories. This is because, for respiratory disease, we publish the number of deaths where it was recorded as the underlying cause only. This is compared to the number of deaths that 'involved' COVID-19 i.e. the number of deaths that mentioned COVID-19 anywhere on the death certificate, whether as the underlying cause or as a contributory factor. A death registration that has respiratory disease recorded as the underlying cause of death and COVID-19 recorded as a contributory factor (involving) would appear in both counts.
Although COVID-19 is a respiratory disease, it is currently coded to emergency ICD codes U.701 and U.702. All other respiratory diseases are coded to ICD codes J00-J99. If COVID-19 was the underlying cause then it would be included in the COVID-19 mentions category but not the respiratory disease underlying cause category. However, if COVID was mentioned as a contributory factor and another type of respiratory disease was the underlying cause then the death would be counted in both the respiratory and COVID categories.
Within our Deaths registered weekly in England and Wales, provisional, figure 2 you can see COVID-19 deaths as both Underlying cause (due to ) and mentions (Involving).
Further information can be found in our Quality of mortality data during the coronavirus pandemic, England and Wales: 2020 publication.