Coronavirus (COVID-19): How are deaths counted?

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This blog looks at how deaths during the coronavirus (COVID-19) pandemic have been certified, recorded and reported and discusses death rates and excess mortality.

Coronavirus (COVID-19) was added to the list of ‘notifiable diseases’ in Scotland on 22 February 2020. This means that medical practitioners must notify relevant authorities if it is confirmed that someone has coronavirus (COVID-19).

Certification and recording of deaths

When a person dies, the death must be certified by a doctor on a Medical Certificate of the Cause of Death form. Due to the pandemic doctors can now send a copy of the form to the register electronically.

The Chief Medical Officer has published Guidance to Medical Practitioners for Death Certification during the COVID-19 Pandemic to help medical practitioners. Deaths can be recorded using the official name of the disease Coronavirus disease (COVID -19) or the official name of the virus, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2).

It is expected that many deaths will be readily identified as coronavirus (COVID-19) deaths. However, the guidance also gives examples of what clinicians should consider when the cause of death is not straightforward. In some cases, a death certificate will be issued stating “presumed COVID-19 disease”.

Assessing whether someone has died of coronavirus (COVID-19), especially in the community, is not an exact science. As with any death, the doctor must decide on the cause of death based on the ‘balance of probabilities’ and use evidence from their own knowledge of the patient, information from the family, carers, about symptoms they were experiencing or from non-prescription medications that might be close to the person, such as cough medicine and paracetamol.

Reporting of coronavirus (COVID-19) deaths

The Scottish Government publishes information on the number of people who have died from Covid-19. The UK Government’s Department of Health and Social Care publishes UK figures. Most of these deaths would have been in hospital rather than in the community, at home or in a care home. For a breakdown of deaths by day see the SPICe blog Coronavirus (COVID-19) in Scotland, which is updated regularly.

National Records of Scotland (NRS) provides information on all registered deaths and causes. As with all deaths there will be a time lag between the date of Covid-19 deaths and registration.

From 8 April, NRS has been publishing information on deaths where Coronavirus (Covid-19) was mentioned on the death certificate. The first mention of Covid-19 on a registered death certificate was the week beginning the 16 March. The data published by NRS is different from the count of deaths published by the Scottish Government. The NRS data includes all deaths where Covid-19 (included suspected cases) was mentioned on the death certificate not just those who have tested positive for Covid-19.

Death rate

There has been much discussion of the death or fatality rate from coronavirus (COVID-19). There have been many different estimates from different countries. This is due to differences in testing and reporting of cases and deaths, and changes as the outbreak progresses. It is likely to be some time before a true fatality rate is known.

There are different types of fatality rate:

  • Case fatality rate is the proportion of people infected who die compared to the total number of identified cases.
  • Infection fatality rate is an estimate of the proportion of infected people that die and tries to take account of asymptomatic and undiagnosed cases.
  • Hospitalised case fatality rate is the proportion of people hospitalised with Covid-19 that die.

As discussed in the Lancet, and mentioned above, one of the major challenges of calculating the case fatality rate is the accuracy of “the denominator”. In this case this means the number of people who are infected with the virus.

In Scotland, most cases of coronavirus (COVID-19) will be going untested as many people will not be showing symptoms or may be self-isolating and, under the current testing regime, will not be tested. The CMO has said that the official infection figures were a “very significant underestimate”. This may lead to an overestimation of the case fatality rate.

Comparisons of death rate estimates between different countries are difficult as there are a number of different approaches being taken to testing.

Germany has been the focus of much discussion as it has reported a low rate of deaths from coronavirus (COVID-19) (up-to-date information on cases and deaths are available from the European Centre for Disease Prevention and Control). The low case fatality rate in Germany has been attributed to:

  • the outbreak being at an early phase;
  • the capability of the health service to meet demand;
  • the age profile of people affected (i.e. they have been predominantly in younger age groups); and
  • a higher number of tests being undertaken.

Excess deaths

Another question is the extent to which the virus will result in excess deaths or whether it is hastening deaths that would have occurred anyway. Professor Neil Ferguson member of the Scientific Advisory Group for Emergencies (SAGE) told the UK House of Commons Science and Technology Committee that:

“we do not know what the level of excess deaths will be in this epidemic, and by excess deaths I mean by the end of the year what proportion of people who died from COVID‑19 would have died anyhow? It might be as much as half to two thirds of the deaths we are seeing from COVID‑19 because it affects particularly people who are either at the end of their life or with prior health conditions.”

He also said:

“Without doubt, most of the mortality is going to be in the elderly and frail, but mortality from the virus among younger age groups is not insignificant; it is substantially higher than, for instance, seasonal influenza. While the absolute proportion of deaths will be low, we will unfortunately see more such instances of mortality in younger age groups.”

We will not be able to tell for some time what the impact of coronavirus (COVID-19) has been and how the decisions of different Governments will have impacted on mortality rates.

Lizzy Burgess, Health and Social Care Senior Researcher