Introduction by Croakey: Experts recently called on Australian governments to re-set COVID policy, warning that unmitigated transmission of the virus in the community has a substantial impact on priority populations including the elderly and immunocompromised.
In addition, concerns were raised about the impact on health services, particularly for Aboriginal health services in the Northern Territory, Long COVID prevalence and an increase in overall mortality.
While acknowledging we are in a better position than three years ago, the World Health Organization also recently urged governments to remain vigilant and strengthen systems for surveillance, clinical care, testing, sequencing, infection prevention and control, treatments and vaccinations.
Meanwhile, the latest analysis of excess deaths by Australia’s Actuaries Institute’s COVID-19 Mortality Working Group suggests the high toll of COVID-19 is set to continue.
Actuaries Karen Cutter, Richard Lyon and Jennifer Lang from the COVID-19 Mortality Working Group summarise the latest findings below, putting them into context with the longer-term trend and consider the outlook for mortality in the short- to medium-term.
Karen Cutter, Richard Lyon and Jennifer Lang write:
We are actuaries who have been monitoring excess deaths in Australia since June 2020. While Australia did well in comparison with the rest of the world in both 2020 and 2021 and excess deaths were relatively small (-3% in 2020 and +2% in 2021), we have seen a significant increase in 2022.
In 2022, mortality was 12 percent higher than our pre-pandemic expectations; that is, there were around 20,000 more deaths than expected across Australia.
Around half of these were caused by COVID-19, and another 15 percent had COVID-19 as a contributing factor. COVID-19 was the third most prevalent cause of death in 2022, after heart disease and dementia and above stroke and lung cancer.
Research has shown that there is an increased risk of death from certain conditions after a COVID-19 infection. These include heart disease, stroke, diabetes and dementia, most of which saw significantly higher than expected mortality in 2022, even after excluding deaths where COVID-19 was listed as a contributory factor.
In 2022, few non-pharmaceutical interventions were mandated to reduce the spread of COVID-19, with vaccination being the main intervention adopted.
However, COVID-19 shows no sign of going away or becoming less serious. It is a new major cause of illness and death in the Australian population, which reduced life expectancy in Australia by around one year of life in 2022.
The outlook for Australian mortality with endemic COVID-19 is uncertain. However, for the next few years at least, it seems likely that we will see more deaths than would otherwise have been expected. It will take time for mortality to reach a “new normal”.
Excess mortality
Excess deaths are the difference between actual deaths and a predicted (or baseline) level of deaths. There is no “standard” way of estimating predicted deaths used in excess death calculations, which is why you may see various estimates of excess deaths for a given country over a given time period.
Our predicted number of deaths represents the expected number of deaths had the pandemic not occurred. It is calculated by allowing for the current size and age composition of the population and the continuation of pre-pandemic mortality improvement trends.
We estimate that excess mortality for 2022 was 12 percent – i.e. deaths were 12 percent higher than our pre-pandemic expectations of mortality. This equates to around 20,000 more deaths than expected (192,000 actual versus 172,000 predicted).
Just over half of these excess deaths (10,300 deaths) are deaths due to COVID-19, another 15 percent (2,900 deaths) are deaths where COVID-19 was a contributing cause of death. The remaining one third (6,600 deaths) did not mention COVID-19 on the death certificate – referred to here as non-COVID-19 deaths.
Digging deeper into our analysis of excess mortality for 2022 shows that:
- deaths from heart disease, stroke and diabetes (all of which are linked to COVID-19 in some way) were all significantly higher than predicted, even after excluding deaths where COVID-19 was listed as a contributory factor
- while most of the excess deaths were in older age groups (i.e. 65+ years), excess mortality was a significant percentage in all age groups in 2022, with females having a higher excess than males
- most states and territories had broadly similar levels of excess mortality in 2022, but the delayed re-opening of WA’s borders is reflected in a delayed uplift in mortality.
How does this compare to previous years?
The number of deaths in 2022 was much higher than the pre-pandemic trajectory would indicate.
Typically, mortality is reasonably predictable from year-to-year, with the biggest uncertainty usually being the level of influenza-related deaths (i.e. will it be a “good” or “bad” flu season?). To have a fluctuation of this level is very unusual.
Another way of putting 2022 in context is to examine period life expectancy.
Note that period life expectancy for 2022 reflects how long a person would live if they experienced 2022 mortality in each year of their life, so it is somewhat artificial. Period life expectancy for a particular year reflects the mortality of that year only; it is not a prediction of future mortality.
The drop in life expectancy in 2022 is the biggest single-year fall seen in Australia in the last 70 years.
Future mortality
There has clearly been a disruption in the Australian mortality trend from 2020 to 2022. With COVID-19 here to stay, mortality will be higher than if the virus had not emerged. But it is unclear how close we are to reaching an endemic state, when COVID-19 deaths will become (more) predictable.
The two main uncertainties around acute COVID-19 deaths relate to prevalence (the frequency and height of future COVID-19 waves) and to potential changes in disease severity when new strains emerge.
We also have a big question mark over what impact the consequences of COVID-19 will have on mortality levels. Study after study shows increased mortality risk for those who have contracted COVID-19, but it is unclear to what extent this will translate to a population-wide uplift in mortality rates, or how long it will last.
We also need to consider the mortality shadow arising from people being either unable or unwilling to access medical treatment in 2020 and 2021. It may still take several years for the full impact of pandemic-related interruptions to medical care to play out.
One lesson learnt during the pandemic is how to better protect the vulnerable from respiratory diseases, including COVID-19, influenza and other respiratory illnesses.
The continued use of masks plus implementation of minimum standards for ventilation in settings such as aged care homes and hospitals will have a beneficial effect on mortality.
Vaccination remains one of the primary measures in our toolkit to limit deaths from COVID-19, and from other diseases such as influenza.
The COVID-19 vaccine has the added benefit of reducing the incidence of Long-COVID and post-COVID sequelae. However, vaccinations are not “set and forget” – vaccines wane over time and it is important that Australians stay up to date with their vaccinations.
Given the above considerations, we expect that it will be some time before mortality reaches a “new normal” state.
About the authors
Karen Cutter is an actuary and was a Principal of a major Australian general insurance consulting firm before taking a career break a few years ago. Finding herself at a loose end during lockdown in March 2020, she developed an interest in COVID-related matters.
Richard Lyon is an actuary who retired in 2021. His last employer was TAL, where he convened a leadership group to assess and manage the impact of COVID-19 on the company. Richard is a co-author and co-editor of the actuarial Control Cycle textbook.
Jennifer Lang is a Non-Executive Director and actuary and is the author of the popular actuarial blog www.actuarialeye.com. She was Convenor of the Actuaries Institute’s COVID-19 Working Group that assisted actuaries across the financial services and health sectors with their responses to COVID-19 during 2020 and 2021.
The authors are all members of the Actuaries Institute and currently volunteer on the Institute’s COVID-19 Mortality Working Group, which regularly reports on excess mortality. The views expressed in this article are the views of the authors, and do not reflect the views of either the Actuaries Institute or any employers, past, present or future.
See Croakey’s extensive archive of articles on COVID-19.
