Information on the COVID-19 pandemic has been hard to digest for a great many reasons but now that the (first) hump is behind us, it is possible to take stock using various totals of cases and deaths that are now, thankfully, increasing more slowly with each week. Here I take a look at two distinct ways to measure deaths due to COVID-19 and why there is a significant difference between them in Scotland.
As of 3 July 2020, the Scottish government reports that 18,287 people have tested positive for the virus and of those 2488 have died. Of the Scottish population, these equate to about 1 in 300 (0.33%) having tested positive and 1 in 2200 people having died (0.05%).
In the whole UK, as of 2 July 2020, the UK government reports that 284,900 people have tested positive and of them 44,198 have died. As a proportion of the UK population this is about 1 in 230 (0.43%) and 1 in 1500 (0.07%).
These fractions may be small but the impact of this virus on those that have lost loved ones and the wider effects on society are anything but.
These headline figures show that 5.6% of COVID-19 deaths in the UK occurred in Scotland, and given that it has 8.2% of the UK’s population, it does seem that Scotland has not suffered quite as much as other parts of the UK.
But these headline figures paint an incomplete picture. If we look at deaths where COVID-19 was mentioned on the death certificate then we find a figure of 4120 for Scotland (as of 21 June) which is two-thirds higher than the 2488 mentioned above.
What explains the difference in these two totals? In the 2488 total, a death is counted only if the person tested positive for the virus while they were alive. This means that some COVID-19 related deaths could well be missing because some people were not tested. In contrast, a doctor can use their professional judgement to record COVID-19 on the death certificate without any test being performed if that person had shown relevant symptoms and if they were known to be close to others who had COVID-19, such as in a care home that suffered an outbreak.
In other words, a likely explanation for the difference between the 2488 and 4120 totals is that deaths are being missed in Scotland’s headline figures because in some cases there was no positive test. Although this is certainly happening elsewhere in the UK, the difference is much smaller with the UK death certificate total of 54,303 being only 23% greater than the one based on positive tests.
To gain another clue for what might explain the discrepancy between Scotland’s death totals we need to look at levels of testing.
According to the Scottish government, a total of 383,722 tests have been “carried out” as of 3 July 2020. The two governments report their numbers of tests differently and so for the UK we have the choice of either tests “processed” at 5.29 million or “made available” at 6.18 million. We have to live with the mismatch, but using these figures we can at least say that somewhere between 6% and 7% of tests in the UK have been in Scotland, a bit below its 8.2% population share.
And so it shouldn’t be too surprising that the 6.4% of positive tests in the UK that were found in Scotland (18,287 of 289,400 mentioned above) falls into this 6% to 7% range. In other words, testing per head of the population is lower in Scotland than elsewhere in the UK as is the number of positive tests.
This all suggests that Scotland’s headline COVID-19 numbers for positive tests and deaths are low not because the outbreak has been less severe in Scotland but because levels of testing have been lower. In fact, Scotland seems to have done not much better or worse than the UK as a whole if we judge it by the fact that its death certificate total of 4120 is 7.6% of the UK’s 54,303 and so close to Scotland’s share of the population.
References
References are given below if you’d like to take a look yourself. Please let me know if you see anything amiss with what I’ve said above.
The pages linked to below will be updated daily or weekly and revisions are not uncommon so don’t be surprised if some of the numbers I use above (written on Sunday 5th July) do not match what you see, but all the main conclusions I came to above have held up with changes over the last week.
Scottish government headline figures
UK government headline figures
Death certificate totals from National Records of Scotland
Death certificate totals for England & Wales
Death certificate totals for Northern Ireland
I’ve collated figures from all the above links and annotated them with more detail in this spreadsheet. It also shows how all the percentages mentioned above were calculated.
EDIT 6 July 2020 08:22 – UK figure for death certificates was corrected but this doesn’t affect any arguments made in this post.
Interesting post. And surprising in the sense that Sturgeon’s statements were mature, realistic and rational. Cf those of England’s ‘King of the World’. Thanks for doing this work Andrew.