During the coronavirus pandemic, the Continuous Mortality Investigation (CMI) is publishing frequent UK mortality analysis through its mortality monitor. The latest update covers week 1 of 2021 (2 to 8 January) based on provisional England & Wales deaths data published by the Office for National Statistics (ONS) on 19 January 2021.
The key points of this update are:
- There have been around 80,100 more deaths in the UK from the start of the pandemic to 8 January 2021 than if mortality rates were similar to those experienced in the previous year. Of these, 19,400 have occurred in the second wave.
- The number of deaths with COVID-19 mentioned on the death certificate was 6,057 in week 1 of 2021, compared to 3,144 in week 53 of 2020. However, the week 1 figure is likely to include deaths where registrations were delayed from week 53 due to bank holidays.
- Considering week 53 of 2020 and week 1 of 2021 together, to reduce the impact of the timing of bank holidays, there were 17% more deaths registered in England & Wales than expected. This compares to 8% more in weeks 50 and 51 of 2020 combined, before the holiday period.
Cobus Daneel, Chair of the CMI Mortality Projections Committee said:
“The ONS figures for registered deaths have been challenging to interpret in recent weeks due to the timing of bank holidays. With this week’s data, it becomes ever clearer that there are significant and increasing excess weekly deaths, with nearly 20,000 so far in the second wave.”
The publication of ONS data broadly follows ISO week numbers. Most years have 52 ISO weeks, but because a 52 week year has 364 days, less than a calendar year, some years, including 2020, have “leap weeks” under the ISO system.
We define “excess” deaths as the difference between actual deaths in a week, and those that we would have expected if mortality rates had been the same as in the corresponding week of 2019. (The exception to this is that we compare week 53 of 2020 to week 1 of 2020, as there was no week 53 in 2019.)
The ONS data released today relates to registered deaths. The timing of bank holidays is likely to have led to a higher number of death registrations in week 1 of 2021 than in the absence of bank holidays, as week 1 of 2021 had no bank holidays and there is likely to have been a “catch up” of death registrations from earlier weeks that did have bank holidays. Considering the pattern of bank holidays in other weeks, we expect that excess deaths in week 1 of 2021 are likely to have been higher, and those in week 53 of 2020 are likely to have been lower, than if the pattern of bank holidays had been consistent.
For the purposes of the mortality monitor, the CMI treats the pandemic as being deaths registered from week 10 onwards (i.e. from 29 February 2020) and the second wave as being registrations from week 38 onwards (i.e. from 12 September 2020).
The CMI intends to publish its next mortality monitor for week 2 of 2021 on Tuesday 26 January 2021. All mortality monitor weekly updates are publicly available on the mortality monitor page.