Why are more people dying in Australia? Many questions remain
The true picture of the excess deaths occurring in Australia differs according to which number-cruncher you refer to.
The official source, the Australian Bureau of Statistics (ABS), puts it at 16.6% more deaths than expected over the course of 2022 so far, with its figures going until the end of May.
However, the Actuaries Institute, an organisation also built around precision with numbers, has reached a different conclusion.
According to its latest analysis, the rate is closer to 12%, with an estimated 8500 more people dying until the end of May than would normally be expected.
The biggest difference – although not the only one – is the baseline number of deaths each organisation uses as its predicted number. While the ABS uses an average from previous years, the Actuaries Institute allows for mortality trends and demographic changes, thus accounting for much of the gap.
Whichever workings are at play, however, the pattern is obvious: excess mortality is significantly higher this year than normal. So does the difference matter?
Yes it does, according to Karen Cutter, an actuary of more than 25 years who helped compile the latest analysis for the institute’s COVID-19 Mortality Working Group.
For her, one of the key questions to emerge from the analysis – and one of fundamental relevance to general practice – is why the excess non-COVID deaths are occurring. With that in mind, ‘getting it right’ is important, she believes.
The Actuaries Institute analysis estimates that a little more than half the excess deaths until the end of May were due to COVID-19 – with an estimated 4200 people dying ‘from’ the disease – making it likely to be the third largest cause of death in Australia this year. Leaving aside an estimated 1280 people who died ‘with’ COVID, that leaves 3700 other deaths where the background increase is not clear.
While much remains unknown, there is detail on which diseases seem to have shifted.
According to the institute, deaths from the respiratory disease are down this year (around 7%), with cancer mortality sticking close to the expected rate, while deaths from heart disease, cerebrovascular disease, diabetes and dementia are all higher.
Other ‘unspecified’ diseases also feature highly, accounting for around 11% of the excess – a trend the institute says has been apparent since April 2021. According to the report ‘history suggests non-ischaemic heart diseases probably make up around 25% of deaths from other unspecified causes’.
But the question remains: why have there been more deaths in these areas this year? For Ms Cutter, previous mortality figure anomalies have been much simpler to unpick.
‘In 2020, there was a lot lower mortality than expected, because we didn’t have flu circulating in the community,’ she told newsGP. ‘I don’t think there’s any kind of mystery about what was happening, then.
‘It’s really [about] trying to get to the bottom of this most recent six months.’
There is work that could be done to help work out what is happening, she believes, including using data that is held by the ABS but not made public.
‘They [look at] the number of deaths by cause, which is how we’ve looked at everything, and they also have a separate cut that’s by age and another one that’s by state,’ Ms Cutter said.
‘But we don’t have the two-dimensional split of age and cause. If we had that we could maybe get a little more insight into what’s going on.’
She also uses the example of possible surveys in major hospitals about stroke deaths to help cast more light on the trends.
‘That’s just throwing out one idea,’ Ms Cutter said. ‘But there are some more qualitative reviews that could be done that aren’t based solely on that ABS data that might give clues as to what is happening or rule out things that aren’t happening.’
With significant increases in COVID-19 deaths since the most up-to-date ABS data was reconciled, the pattern is likely to remain similar until the end of August, she believes.
Last month, COVID-19 surveillance deaths were the highest yet recorded for the second month in a row, with deaths from the disease representing a 9% surplus on predicted levels from June to August, according to the Actuaries Institute analysis. It also says overall excess mortality is likely to be higher still.
‘Given that we don’t really know the factors that are driving the increase in that first five months, we can’t say for sure that excess [deaths] would continue, but I can’t see a reason why it wouldn’t for those months,’ Ms Cutter says.
The most likely cause for non-COVID-19 excess deaths, the Actuaries Institute suggests, is ‘post-COVID-19 sequelae or interactions with other causes of death that may be having a ‘high’ impact in Australia.
‘Studies have shown that COVID-19 is associated with higher subsequent mortality risk from heart disease and other causes,’ its analysis states.
‘However, we understand that medical science has not yet established a causative link that would allow, say, a heart attack several months after a COVID-19 infection to be attributed back to COVID-19.
‘As such, it seems likely that there would be more of these deaths than identified.’
Delayed deaths from other causes could be having a ‘moderate’ effect on the numbers, the institute suggests, with health system pressures leading to people avoiding help or not getting timely care likely to be having ‘low-to-moderate’ impact.
Delays in routine care, including for diagnostic testing for non-COVID-19 causes and elective surgery, are also categorised the same way.
‘While [delays leading to later mortality] … does not yet appear to be occurring for cancer deaths, it may be a factor in higher deaths from other causes, such as ischaemic heart disease, diabetes, and the large “other” category,’ the report states.
Lifestyle changes prompted by the pandemic such as drinking more and exercising less are likely to be having a low impact in Australia, while the probable influence of vaccine-related deaths and undiagnosed COVID-19 are ‘negligible’, the analysts believe.
Whatever factors are at play, Ms Cutter is very careful not to make any predictions about whether the pattern of more people dying than expected is likely to continue.
‘I don’t really have any insight into where COVID is going to go beyond anybody else. Doing predictions for COVID numbers is really not in my ballgame,’ she said.
‘That’s always the question that people ask you, “well, what’s next?”’.
‘That’s what we all know want to know. That’s what I want to know as well.’