Reconciling COVID-19 death data in the UK – a lay summary
How many people have died from COVID-19 in the UK? It’s complicated. Different official sources give different answers. Let’s look at why this happens for the updates on the numbers of COVID-19 deaths compiled and published for England and the UK.
- Public Health England (PHE) publishes on their dashboard daily totals of COVID-19 related hospital deaths in England notified up to 5pm on the previous day, alongside those from the devolved administrations of Scotland, Wales and Northern Ireland. These are deaths in NHS hospitals of patients who have had a positive test result for COVID-19. People dying outside NHS services, such as in care homes, are not included. And some who tested positive for COVID-19 in hospital could in fact have died from a different cause. The date reflects when PHE was notified of the patient’s death, not the date of the death itself.
- NHS England also releases a daily count of patients who died in hospitals in England and who tested positive for COVID-19 at time of death. Here, all deaths are recorded against the actual date the patient died. When you consider that confirming the COVID-19 diagnosis and notifying the death can take several days and the hospitals providing the data are under enormous pressure, it is not surprising if the daily total reported at 5pm may not include all of that day’s actual deaths. Also, the number of COVID-19 deaths recorded for a particular day may later have to be changed if post-mortems conclude the cause was something else. So, NHS England’s figures for numbers of deaths – certainly those for the previous five days – can be expected to change retrospectively.
- The Office for National Statistics (ONS) data, on the other hand, are compiled from information supplied once deaths are actually certified and registered, so there is a time lag of several days between the date of death and that death appearing in the ONS figures. Unlike PHE and NHS England, ONS figures include cases outside hospital and will also include some cases where COVID-19 is suspected, but no formal diagnostic test has taken place. The ONS data currently covers England and Wales only.
So, if you were to compare deaths for a particular day you would find the figure given on the PHE dashboard may not match either the NHS data nor most of the ONS data. Revisions of earlier totals as late certifications and post mortem results come in makes it difficult to be sure about patterns of death rates seen in the short term.
The current data tentatively suggest a slowing in the rate of deaths consistent with hitting a peak.
The Oxford CEBM team recommend that NHS England and PHE use data on the actual date of death, which will provide a better understanding of the peak deaths in the pandemic.
Mandy Payne, 10th April 2020
Disclaimer: the article has not been peer-reviewed; it should not replace individual clinical judgement and the sources cited in the original report should be checked. The views expressed in this commentary represent an interpretation by HealthWatch and do not necessarily represent those of Oxford CEBM, the NHS, the NIHR, or the Department of Health and Social Care. The views are not a substitute for professional medical advice.