How COVID-19 has affected mortality in 2020 to 2022

The Australian experience

The research paper "How COVID-19 has affected mortality in 2020 to 2022" offers insights to inform public policy on healthcare, social support and emergency preparedness while providing a robust foundation to mitigate the pandemic’s impact on mortality and well-being.

The Mortality Working Group estimates that there were almost 20,000 (11 %; 95% confidence interval of 9 %-13 %) more deaths in Australia in 2022 than would have been expected if there had been no pandemic. Excess mortality is widely regarded as the best measure of the overall impact of a pandemic, since it includes deaths both directly and indirectly due to the disease. Of the 19,200 excess deaths in 2022, the authors estimate that:

• 10,300 deaths (54%) were from COVID-19
• 3,000 deaths (15%) were COVID-19 related, meaning that COVID-19 contributed to the death; and 
• 5,900 deaths (31%) had no mention of COVID-19 on the death certificate.

Deaths from COVID-19 are those where COVID-19 is given as the underlying cause of death on the death certificate. Deaths from COVID-19 were the third leading cause of death in Australia in 2022. COVID-19 related deaths are those where COVID-19 was a contributing factor mentioned on the death certificate. 

Yet it is unclear how close we are to reaching an endemic state, when the impact of COVID-19 on mortality will become (more) predictable. Latest data shows that the December 2022/January 2023 wave of COVID-19 deaths had ended by February 2023 (similar to the lowest month of 2022 at around 350 deaths), and a new wave of COVID-19 deaths was apparent in April/May 2023. 

The death certificates of about one-third of excess deaths in 2022 had no mention of COVID-19. These non-COVID-19 deaths represent excess mortality of 4%, which is extraordinarily high in itself, particularly given that the 2022 influenza season was representative of an “average” year and that the severity (or not) of the flu season usually dictates any significant variation from trend. Non-COVID-19 excess deaths are particularly apparent in those aged over 75 for both genders, and those aged under 65 for females only. We consider that the most likely reasons for these excess deaths are:

• the impact of COVID-19 on subsequent mortality risk, particularly heart disease, stroke, diabetes and dementia, which have all been identified in studies
• delays in emergency care, particularly at times of high prevalence of COVID-19 and/or influenza; and
• delays in routine care, which refers to missed opportunities to diagnose or treat non-COVID-19 diseases and the likelihood of consequent higher mortality from those conditions in future. According to medical professionals, disrupted prescription of medications may be particularly likely to be a major risk factor for those with chronic heart disease.

Other possible reasons, which, according to the work group, have had less impact in 2022, include:

• mortality displacement, which refers to the proposition that many lives that were saved by the reduced spread of respiratory disease in 2020 and 2021 represent vulnerable people who would soon die of their underlying conditions;
• undiagnosed COVID-19, which clearly happened early in the pandemic, but seems far less likely in 2022, given awareness and testing protocols;
• mental health issues, widely understood to have arisen from stress associated with the pandemic, but not (or not yet) showing up in any significant way in suicide mortality data; and
• road deaths, which were up a little in 2022 but are not of the magnitude required to significantly impact excess mortality.

In this context, the editors note that vaccination is highly unlikely to be a cause of excess mortality in 2022. Indeed, given the well-documented reduction in COVID-19 mortality risk conferred by vaccination, the 14 confirmed vaccine-caused deaths that had occurred by June 2023 are a fraction of the lives saved by vaccination.

World-wide experience

In a global context, the data shows that almost all countries had positive total excess mortality across the three years 2020-22, with a weighted average of 14%. 

New Zealand (-0.5%) was the only exception among the 40 countries shown in the research paper, while excess mortality has been very high in Latin America, averaging about 24% over the three years. South-East and East Asia have generally fared much better than Other Asia. Similarly, Northern and Western Europe has generally had lower excess mortality than Southern and Eastern Europe. The United States have experienced 14% excess mortality across the three years, far higher than Canada (5%). The difference is mostly due to COVID-19, with excess mortality from other causes at 2% in the United States and -1% in Canada, although there is evidence that deaths from opioid poisoning, road deaths and firearms deaths have continued to increase in the US.

In general, it's noted that those countries with higher excess mortality in 2020 and 2021 appear to have lower excess mortality in 2022, and vice versa, but that the overall level of excess mortality across the three years is lower the later the occurrence of the peaks.

Mortality outlook

The editors estimate the “new normal” level of mortality to be likely higher than it would have been in the absence of a pandemic. Accordingly, 2022 had 11% higher than predicted mortality. Their analysis of the latest ABS Provisional Mortality Statistics shows 6% excess mortality in 2023 Q1, with a likely upward trend for April and May. They deem 2023’s excess to be likely lower than 11%, but probably at least 5%. Looking further ahead, excess mortality (relative to no pandemic) will gradually decline over time. 

While the level of excess mortality is ought to decline, COVID-19 is likely to continue to cause some excess mortality for some years to come, directly as a cause of death and, less directly, as a contributor to other causes such as heart disease. There will also be an indirect impact, with the largest contributor likely to be the ongoing consequences of disruption to usual healthcare practices in the last three years. Counter to this, to the extent that mask-wearing and other defence measures persist in vulnerable settings, this will likely lead to lower deaths from respiratory disease.

This article is based on information kindly permitted by the Actuaries Institute. For further details please visit https://www.actuaries.digital/articles/.

The full research paper is available for download here https://www.actuaries.asn.au/Library/Opinion/2023/REPORTV2COVID19.pdf