What is going on with excess deaths?

Mark McLaughlin from The Times Scotland has recently asked me what I think about the current COVID-19 situation in Scotland and the direct and indirect impact of the pandemic on excess deaths. The resulting article can be found here (behind paywall). Here is a bit more detailed response to the question:

Why does coronavirus now account for less than half of excess deaths in Scotland?

Mark McLaughlin, rephrased

Two sources of data can be used to look at it in more detail. Firstly, Human Mortality Database (which I used in the past here) provides information on excess deaths, i.e. the number of deaths above (or below) the long-term average. Mortality varies from year to year, with particular increases in winters of bad seasonal flu. It also varies between seasons, with lower mortality in summer and higher in winter (in the Northern Hemisphere, and in the temperate climate zone). Over the last 19 months, most countries in the world have experienced many more deaths than usual – far exceeding the ‘usual’ variation.

Secondly, I have recently been looking in great detail at Scottish COVID-19 data, from the Public Health Scotland web page, particularly the number of reported cases and the number of deaths attributed to COVID-19.

Both sets of data are potentially problematic. Excess deaths have arguably been the best indicator of how severe the COVID-19 has been. It is because they are ‘clean’ and not prone to misinterpretation (The only possible query is for the date of death – is it when it is reported, or when it actually occurred? But this is really a minor quibble not affecting the magnitude and general pattern.). In most developed countries there is a very solid system of reporting deaths and it is not easy to either hide them or artificially inflate them.

Deaths attributed to COVID-19 might be more questionable. Most developed countries have adopted a criterion, usually a person whose death doctors attribute to COVID-19 within 28 days from the date of COVID-19 being diagnosed. But it is open to interpretation of whether a person died from or with COVID-19. Still, as long as the attribution is consistent, we can look at the general patterns, even if the numbers might be a bit uncertain.

Top graph: excess deaths in Scotland. The blue line represents the average 2010-2019 and the black line is for 2020 and 2021. Bottom graphs: number of reported cases (black points and a blue line showing running weekly mean) and deaths number of reported cases (red points and a red line showing running weekly mean), in 65-74, 75-84, and 85+-year-olds.

In both data sets, we get three large waves, March-July 2020, September 2020-April 2021, and the most recent one. Mortality – both COVID-19 related and excess – is clearly reduced in the most recent wave, thanks to the vaccination rollout which thankfully preceded the third wave.

The first two excess mortality waves are clearly correlated with the case numbers and COVID-19-attributed deaths. Look how massive – and concentrated – the early 2020 peak was. Later on, we can clearly see the two peaks of the second wave – one in late 2020 and one in early 2021. In the first two waves, excess deaths follow COVID-19-attributed deaths quite closely, rising up and falling down in remarkable accord.

But not any more. In contrast, the current excess death wave is a slow-growing one which does really follow the ups and downs of the COVID-related deaths in the pictures.

My reading of it is that we now see a combination of three factors:

1. A delayed wave of non-COVID health problems caused by people not accessing health care over the last 19 months and by unhealthy life style last year – it might take several months for people who delayed their treatment last year and earlier this year to get to the point when they actually die of cancer, heart, or kidney failure.

2. A growing wave of COVID and non-COVID health problems caused by the effective collapse of health system now. Given my own experience of health care in Scotland I am not surprised – I have had some health problems recently and getting quality medical help was not easy as my GPs were clearly under duress. Additionally, getting medication in the local pharmacy is a challenge and takes days when previously it was either in stock or next day. A friend had to wait over the weekend to get an antibiotic for a serious infection.

3. Finally, an increase in COVID deaths caused by the current epidemic wave. Vaccines seem to work very well for 45-84 year olds, but I was surprised to see how close the data for cases and deaths follow each other for 85+ – meaning that a similar proportion of them have died with and without vaccines throughout the whole period.

Note also that we are now seeing many more cases – a lot of this is due to much better reporting but the current wave must be putting a lot of pressure on GP and hospitals.

So, what is the conclusion? It looks like we are in for a difficult winter of a double whammy – a combination of COVID-19 (which we as a society and our governments are not able or not willing to stop) and a long-lasting, slow but relentlessly growing wave of health problems caused indirectly by the pandemic.