FOI Ref: FOI/2022/4598
You asked
I would like to enquire how the following statement by ONS is arrived at please:
"Influenza and pneumonia was mentioned on more death certificates than COVID-19, however COVID-19 was the underlying cause of death in over three times as many deaths between January and August 2020."
Within the response I would like you to share how the cause is differentiated by you using the data provided to you and also how the data is differentiated when supplied to you.
A list of sources of data for this particular spread would be welcome too. Basically, is it all NHS data?
We said
Thank you for your enquiry.
Our data is derived from information collected at the point of death registration. Under Section 42 of the Statistics and Registration Service Act 2007 (SRSA) the Registrar General for England and Wales discloses to ONS on a daily basis the following registrations recorded on Registration Online (RON) by the Local Registration Service: births, marriages, deaths, stillbirths and civil partnerships.
When a person dies, in most cases a doctor writes a medical certificate of cause of death (MCCD) which is then recorded in the death registration (at a local authority registration office). The doctor or coroner certifying a death can record more than one health condition or event on the form.
The medical certificate of cause of death has two parts, Part 1 contains the sequence of health conditions or events leading directly to death, this is the underlying cause of death, or we use the term "due to".
Part 2 can contain other health conditions that contributed to the death but were not part of the direct sequence. We call this a "mention" or use the term "involving".
For statistical purposes one of the health conditions on the certificate is chosen as the 'underlying cause of death'. All the conditions mentioned on the death certificate are coded using the International Classification of Diseases, Tenth Revision (ICD-10). From all of these causes an underlying cause of death is selected using ICD-10 coding rules.
The underlying cause of death is defined by WHO as:
a) the disease or injury that initiated the train of events directly leading to death,
or
b) the circumstances of the accident or violence that produced the fatal injury
The ICD-10 cause code for Influenza and pneumonia is J09 -- J18 and in this report for COVID-19 are U07.1 and U07.2.
You can read in detail about the coding of causes of death and identifying the underlying cause in the ONS User guide to mortality statistics and the WHO International Classification of Diseases (ICD-10) instruction manual.
For the period of the referenced report, there were 70,027 death occurrences in England and Wales where influenza and pneumonia were mentioned on the death certificate, whilst there were 52,237 occurrences where COVID-19 was mentioned on the death certificate.
However, influenza and pneumonia were the underlying causes of death on 14,013 deaths against 48,168 deaths that were "due to" COVID-19. Therefore COVID-19 was the underlying cause of death over three times more than influenza and pneumonia. This information can be found in Table 6 and Table 7 of the Deaths due to COVID-19 compared with deaths from influenza and pneumoniadataset.
If you have any further queries about the information presented in this response, please contact the Health And Pandemic Insights (HAPI) Customer Services team on Health.Data@ons.gov.uk.