What is causing Excess Mortality in Australia?

The Australian Bureau of Statistics (ABS) has just released mortality data up till January 30 2022. Unfortunately, the data is 3 months behind real time but it’s the best we have. I note that the ABS does do a good job when it comes to releasing and presenting data, compared with other Australian agencies. The headline graph from the report is below:

The graph shows total deaths in Australia week to week. The Excess Deaths in this last year are worryingly high. They track outside the range of the historical records used to define an average baseline. For 2021 this is years 2015-2019. Note that the middle of the year is our Winter and therefore flu season. This is when many of the elderly population sadly pass away. 2017 was a bad year for influenza so that particular year defines the upper extent of the blue shaded area in the middle of the year in the graph above.

The vertical axis on the left is deaths week to week. The scale starts at 2,500. In 2020 the total deaths in Australia for the year was 161,300. This is 52 weeks times roughly 3100 deaths per week.

The ABS advises that for the year period, from 1 Feb 2021 to 30 Jan 2022, deaths were 22% greater than baseline. This is alarming, but these are strange times.

The accompanying ABS narrative is a bit misleading. You see they show a big COVID infections curve to make it look like the peak in the red curve at the right hand side is all COVID deaths. It is not. There are still many unexplained deaths after subtraction of COVID. The ABS tries to explain this as being due to coinciding with Delta and Omicron waves of the pandemic. However, Omicron only has its effect in the last month of the period (January). Deaths in Australia before that are relatively low due to the severe lockdowns and quarantining of incoming travelers.

Omicron arrived in Australia, with fully vaccinated travelers allowed to return, late in the year. COVID deaths per week are less than 100 up until January when Omicron kicks in. The total COVID deaths in this period is 2853.

Excess mortality is being looked at around the world. I wanted to look at what are the Excess Deaths, not including COVID, in Australia. The following graph is the result:

The dark red, jagged looking, line is the actual week to week value for Excess Deaths expressed as a percentage of the baseline of expected deaths for that week. The bold red line is a smoothed curve fitted to the Excess Deaths for each week. The grey shaded area is an estimate of the confidence of the fit.

Note again that I have taken out any COVID deaths before calculating the excess. There are really only significant COVID deaths during this year long period in January 2022, ie at the end, as Omicron starts. So what is shown in the graph above is unexplained excess deaths. They are consistently above zero (ie in the red shaded region – red is bad) except for 4 weeks at the end of Winter where it sits close to zero.

My interpretation is that the Excess Deaths early in the 2021 are due to the effects of hard lockdown, eg elderly dying in despair, people not getting medical attention required. Another possibility is it is deaths somehow postponed from an earlier period. It starts heading back to zero but this could be an artifact. In Winter we typically have a high number of deaths due to influenza and that makes the baseline (based on 2015-2019 data) relatively high to start with. See the ABS graph. With lockdowns and no influenza the baseline used should probably be lower but we stick with the convention. For example, Excess Deaths went negative during the first year of the pandemic, in 2020, during our Winter.

After Winter Excess Deaths start shooting up. We don't know where it is going. It coincides with the rapid uptake phase of the initial mass vaccination campaign with threat of job loss otherwise.

The dashed blue line is the total number of persons who have received one shot. The number is shown on the right-hand vertical axis. Australia’s population is approximately 25 million so you can see the high vaccination rate in Australia. The boosting is shown as a dotted line. It is too early in this data to see any influence of boosters.

Like all the pandemic data the graph shows a lot of information that is challenging to convey. I came across a visualisation Steve Kirsch referenced in his newsletter recently, on excess mortality in Cyprus (population 1.2 million):

Cyprus has a slightly higher death rate per thousand compared to Australia (7.3 vs 6.4).

The clever thing about showing the data this way is that the seasonal effects are taken out. Each bar chart shows a period, one quarter, where deaths are relatively consistent year to year. For example in the above Q1 includes Winter in the northern hemisphere so there are higher average deaths than Q2, Q3. The person who did this is @masimaux on Twitter.

But in the second half of 2021 (Q3 and Q4) there are clearly deaths that are unexplained after taking out COVID deaths. I’ll look at the Australian data this way too. ABS also includes some age breakdown data. This will be interesting to look at. Are particular age groups subject to this excess mortality? In the US there have been reports from Insurance companies of excess mortality of up to 40% in the less than 40 age group.

This is an unfolding story across the world.