Why does the UK count deaths?
Mortality data has many uses. It can be used to assess population health and health care needs, plan health and other public services, evaluate the effectiveness of such services, identify inequalities, inform medical research and more. Information from death certificates compiled by the ONS provides the main source of national data on deaths. Details of the deceased person, such as name, date of birth, gender, cause and place of death, are recorded on the death certificate. The aggregated ‘vital statistics’ produced from this information are used to calculate mortality rates for different causes of death. The data can also be analysed in different ways, for example, to show how mortality rates vary between different population groups and areas and how they are changing over time.
As with deaths from other causes, deaths from Covid-19 are registered and recorded in official statistics. However, these processes take time and some delay in reporting the numbers is unavoidable. Being a new, potentially dangerous and highly infectious disease that is spreading rapidly, monitoring the scale, spread and impact of the Covid-19 pandemic on a daily basis is vital for containing and managing it. This means new ways of counting Covid-19 deaths have had to be developed.
How are deaths usually counted?
Registration of deaths is mandatory in most countries. Deaths in England and Wales are required by law to be registered within five days, unless there is to be a coroner’s post mortem or an inquest. A medical certificate of cause of death (MCCD) is required for the death to be registered. The doctor who last attended the deceased has a legal responsibility to complete the MCCD, but if this isn’t possible for any reason, eg, if the doctor is self-isolating, the Coronavirus Act 2020 allows any doctor to complete the MCCD.
Among the personal details of the deceased person recorded on the death certificate by the registering doctor is the cause/causes of death. Every death will have an ‘underlying’ cause recorded, along with any other causes that may have contributed to the death (‘contributory’ causes) – taken together, these are called ‘mentions’ (deaths with a cause appearing anywhere on the death certificate).
For many conditions, eg, lung cancer and stroke, the ONS uses the underlying cause to count deaths. However, like influenza, Covid-19 can cause death directly or precipitate death from other causes, hence ONS uses ‘mentions’ to get a more complete count Covid-19 deaths.
How are Covid-19 deaths counted?
Because of the unavoidable time lags in the usual process of registering deaths and analysing and reporting the data, additional routes are being used to count Covid-19 deaths. There are three data sources on numbers of Covid-19 deaths currently in use.
- The Department of Health and Social Care releases daily updates in briefings and on GOV.UK on the numbers of deaths in the UK, reported up to the day before, among all cases where there was a positive test for coronavirus – a broader definition than that used before 29 April 2020, when the figures for England included only deaths in hospitals and not those in care homes and other community settings. This means that deaths reported for England are now consistent with those reported the rest of the UK. The Department of Health and Social Care data reports deaths in people with Covid-19 and not necessarily due to Covid-19, and it does not include deaths in people where Covid-19 was suspected but a laboratory test was not done or was negative. Some negative tests may be ‘false negatives’ if, for example, the virus was present in small amounts, or the specimen from the throat or nose wasn’t taken correctly, or because the tests are not always accurate.
- NHS England and NHS Improvement release daily updates of deaths in hospitals in England among patients who have tested positive for Covid-19 by date of death, rather than when the death was reported. This gives a timely estimate of the number of hospital deaths occurring daily, but it is also subject to the caveats described above for Department of Health and Social Care data. The numbers of deaths for more recent dates are updated in each release.
- The ONS provides figures weekly based on deaths certified and registered in England and Wales with Covid-19 recorded as an underlying or contributory cause of death (ie, all ‘mentions’ of Covid-19 on death certificates). The figures include all Covid-19 deaths, in all settings, whether tested for Covid-19 or suspected by the certifying doctor. ONS data takes longer to prepare (see above), with a reporting delay of 11 days from the date of death due to processes around death certification.
Key features of the different data sources for Covid-19 deaths are shown in Table 1. In summary, the strengths and limitations of each data source are as follows.
- Timeliness: The Department of Health and Social Care and NHS England and NHS Improvement figures are useful for informing the government’s response to tackling the pandemic because they are available quickly and indicate what’s happening to deaths day by day. The ONS data entails a delay of 11 days, a significant limitation when numbers of deaths are changing rapidly.
- Accuracy: The Department of Health and Social Care and NHS England and NHS Improvement data doesn’t include deaths in people where Covid-19 was suspected but not confirmed by testing, which could affect the completeness of the numbers. Moreover, some deaths of people who tested positive for Covid-19 could be due to a different cause. The ONS deaths data includes both deaths in people who have tested positive and those not tested but where the doctor suspected Covid-19 based on the symptoms, making coverage more complete and cause of death as involving Covid-19 more reliable.
- Potential for analysis: The Department of Health and Social Care and NHS England and NHS Improvement numbers are simple counts without details about the people who died, so they cannot be analysed further. Because ONS data is based on death certificates that record key details about the deceased person, it can be analysed in different ways to enhance understanding of mortality patterns, for example, by age, gender, cause of death, area and whether or not the deceased had a pre-existing condition. This is important because, for example, such analyses show that men, older people and those with pre-existing diseases are at greater risk of dying from Covid-19.
|Department of Health and Social Care||NHS England and Improvement||ONS|
|Geography||UK, England, Scotland, Wales, Northern Ireland||England||England and Wales|
|Event type||Counts of deaths provided by Public Health England, Scotland, Wales, Northern Ireland||Counts of deaths reported by hospitals in England||Death certification data|
|Timeliness||Deaths in previous 24 hours reported daily||Deaths in previous 24 hours reported daily by date of death||Weekly deaths reported with 11 days delay because of time from death to registration|
|Coverage||Tested positive||Tested positive||Tested positive and deaths where no test was done but the certifying doctor suspected Covid-19|
|Cause of death||Tested positive||Tested positive||Deaths where Covid-19 was an underlying cause or contributory cause, ie, all ‘mentions’ of Covid-19 recorded anywhere on the death certificate|
|Place of death||Deaths testing positive and suspected in all settings||Deaths testing positive in hospital||Deaths testing positive and suspected in all settings|
Figure 1 shows data on Covid-19 deaths in England up to and including 12 May 2020 (as ONS data has a delay of about 11 days, a comparison with the Department of Health and Social Care and NHS England and NHS Improvement data for the most recent days isn’t feasible). The updated reporting method used by Department of Health and Social Care to include deaths outside hospital shows higher numbers than the data reported by NHS England and NHS Improvement which only includes hospital deaths. The ONS numbers significantly exceed both, because they include cases where Covid-19 was recorded as a cause of death but there was no laboratory-confirmed test. The ONS reports that the total number of Covid-19 deaths occurring in England to 1 May 2020 was 33,337, compared with the number to this date reported by Department of Health and Social Care of 24,763 and by NHS England and NHS Improvement of 21,764.
What impact is Covid-19 having on overall mortality?
Covid-19 deaths are having a significant impact on overall mortality. Figure 2 shows the weekly number of Covid-19 and total deaths and the five-year average of weekly total deaths in England and Wales for the year to date. Total deaths from the start of the year to late March 2020 were in fact lower than or similar to the five-year average for 2015–19, in part due to a mild influenza season in the 2019–20 winter. But the sharp rise in Covid-19 deaths from late March caused a sharp spike in overall deaths, resulting in almost 46,000 excess registered deaths to 1 May 2020 compared with the average for 2015–19. From week ending 24 April total deaths have started to decline, reflecting falling numbers of Covid-19 deaths.
In addition to its direct impact on overall mortality, there are concerns that the Covid-19 pandemic may have had other adverse consequences, causing an increase in deaths from other serious conditions such as heart disease and cancer. This is because the number of excess deaths when compared with previous years is greater than the number of deaths attributed to Covid-19. The concerns stem, in part, from the fall in numbers of people seeking health care from GPs, accident and emergency and other health care services for other conditions. Some of the unexplained excess could also reflect under-recording of Covid-19 in official statistics, for example, if doctors record other causes of death such as major chronic diseases, and not Covid-19. The full impact on overall and excess mortality of Covid-19 deaths, and the wider impact of the pandemic on deaths from other conditions, will only become clearer when a longer time series of data is available.
From early March 2020, when the first Covid-19 deaths were reported, to 1 May 2020 there had been 35,044 Covid-19-related deaths in England and Wales. As Covid-19 deaths are continuing to rise, the number to date already exceeds the annual count of deaths from stroke and lung cancer, which are the fourth and fifth leading causes of death (about 31,000 and 30,000 deaths respectively in 2018).
Where are Covid-19 deaths taking place?
The ONS data shows where deaths from Covid-19 are taking place because place of death is recorded on death certificates.
ONS analyses show that in the five-year period 2015–19, 47 per cent of all deaths occurred in hospital, meaning 53 per cent took place elsewhere (mostly at home (24 per cent) and in care homes (22 per cent)). This pattern changed when deaths related to Covid-19 and all deaths started to rise sharply (see Figure 3).
Deaths in hospital increased sharply from late March 2020 but have been falling since week ending 17 April 2020 (see Figure 3). A high proportion of hospital deaths have been certified as Covid-19; testing for Covid-19 in the earlier stages of the pandemic was focused on hospitals.
The sharp increase in deaths in care homes came somewhat later – in April – and was especially marked (see Figure 3). By week ending 1 May 2020, the number of people dying in care homes equalled the number of people dying in hospital, and the number of deaths was almost three times higher than the average weekly number of deaths in care homes over the past five years. Deaths in care homes started to decline from week ending 24 April 2020, somewhat later than hospital deaths. The reasons for the relatively low proportion (42 per cent) of ‘excess’ care home deaths since March attributed to Covid-19 are unclear. Data from several European countries suggests that up to half of those who have died from Covid-19 were residents of care homes. Although international comparisons are not straightforward because of differences in data and definitions, the comparative figure for England and Wales of 25 per cent up to 1 May 2020 appears low, suggesting the data may under-estimate deaths attributable to Covid-19.
The number of deaths at home also increased sharply since the start of the pandemic (see Figure 3), with a relatively small proportion (14 per cent) of the excess deaths during this period coded as Covid-19. Deaths at home are also now falling.
What is the impact of Covid-19 on different population groups?
Data gathered in the UK and globally during the current pandemic has revealed some risk factors for experiencing serious complications or dying from Covid-19.
Age: While some young and middle-aged adults can develop serious complications or die from Covid-19, the risks rise significantly with age. This is thought to be because immune systems tend to deteriorate with age and because older people are more likely to have chronic conditions. For example, the mortality rate at ages 80–84 in England and Wales is about ten times greater than at ages 60–64.
Gender: Men are more likely to develop serious complications and die from Covid-19 than women. The mortality rate among males (97.5 deaths per 100,000) is double that of females (46.5). Various reasons have been put forward for this gender difference, but none has been scientifically established yet.
Pre-existing disease: About 90 per cent of deaths involving Covid-19 occur in people with pre-existing conditions, such as heart disease, respiratory disease, diabetes or kidney disease, resulting in weaker immune systems that reduce the ability to fight infection.
In the UK, there are other commonly reported risk factors.
Deprivation: Socio-economic inequalities in health and mortality in England and Wales have been reported for decades and they are widening. The direct and indirect impacts of the Covid-19 pandemic can exacerbate this inequality for several reasons, eg, because of differences in occupational exposure to infection and higher levels of pre-existing disease and household density among more deprived groups. ONS data for 1 March to 17 April 2020 for England shows that the rate for deaths involving Covid-19 in the most deprived decile of areas (55.1 deaths per 100,000 population) was 118 per cent higher than the rate in the least deprived decile (25.3). This exceeded the 88 per cent differential between the overall mortality rates for the most (229.2 per 100,000 population) and least (122.1) deprived areas.
Ethnicity: It is widely reported that people from some Black, Asian and minority ethnic (BAME) populations are significantly over-represented among deaths from Covid-19. Analysis by the ONS shows that the risk of dying from Covid-19 among people from Black groups is almost double that of the White group, with Pakistani and Bangladeshi groups showing a slightly smaller excess. (This analysis involved linking death records to the 2011 census to obtain the ethnicity of the deceased from the census record.) Higher mortality is reported also for NHS and social care staff from BAME groups. The excess Covid-19 mortality in BAME groups is only partially attributable to clinical factors and deprivation. Such findings have led to calls for an inquiry. Public Health England is conducting a review to examine why people from BAME backgrounds appear to be disproportionately affected by Covid-19. In England ethnicity is recorded in patient records but not on death certificates, and there have been calls for this to be revisited.
In summary, while we know some of the risk factors for Covid-19, there is much that is unknown. Over time, when there is a sufficient volume of reliable data from the UK and elsewhere, epidemiological research will help to answer critical questions about the impact of this virus on different population groups.
How do the numbers of Covid-19 deaths in UK compare with other countries?
International comparisons of deaths and mortality rates for Covid-19 are available from several sources, including the daily ministerial briefings by the Department of Health and Social Care and the media. While such comparisons may provide an overview, there are limitations to them, for example, differences in the way deaths are counted (eg, hospital-only or all settings), in how many people are tested and in the demographic structure of the population (eg, mortality rates vary by age and sex). These caveats notwithstanding, the available data shows that Covid-19 deaths in UK are among the highest in Europe.
An alternative approach to international comparison aims to capture the overall impact of the pandemic by examining the excess in total deaths since the outbreak of the 2020 pandemic over the number expected based on a historical benchmark. Such analysis suggests that thus far UK compares worse than Italy, France and Germany, and comparably with Spain. This approach avoids many of the above problems with counting Covid-19 deaths but also has some caveats, including the choice of baseline period used for comparison. Whatever method is used, it is too early to draw definitive conclusions because it’s unclear what the final comparisons will show once the pandemic has passed.
Covid-19 and the wider impacts of the pandemic have had a significant impact to date on overall numbers of deaths, where they occur and the population groups most affected. While some mortality patterns are detectable from the data available to date, much will depend on the future trajectory of the pandemic. Further analyses of overall, cause-specific and excess mortality are needed to better understand mortality trends and differentials, within and across countries, and require longer time series of data. Moreover, as mortality patterns suggest Covid-19 is under-recorded in death certification, as with influenza, alternative methods of estimating these deaths may also be required.