EXPERT REACTION: No evidence of excess deaths in NZ and Australia due to pandemic

People suffer ill health and deaths as a result of both the direct and indirect effects of disasters. The direct effects are those caused by the hazard (in this case infection with COVID-19). The indirect effects are those caused by the effect of the disasters on social infrastructure (e.g. lost access to healthcare) or by efforts to manage the disasters (social isolation and lockdown). The latter may include its impact on mental health. Thus, often the actual death rate form disasters exceeds those who are directly killed as a result.

It is well known that the number of people who have died during this pandemic exceed those who have been recorded as dying from COVID-19. The additional deaths may include people who did die of COVID-19 but who were not tested. It may also include people dying as a result of other causes such as lost access to their routine and life preserving health care because the health services were consumed with management of the pandemic or because they were concerned to seek health because of a perceived risk of catching the virus.

On the other hand, because of enhanced social isolation (lockdown), it has suggested that there may be a reduction in deaths of other causes; less traffic or work accidents and fewer deaths from other infectious diseases such as influenza.

This article has analysed the number of deaths in 21 countries that have occurred over a period of 14 weeks from February to the end of May 2020. They have compared those number of deaths to the number that would ordinarily be expected to have occurred over that time and found a range of outcomes from a reduction in the number of deaths in some countries (including Australia) to an increase of more than 35 percent in some of the worst affected countries.

Thus, in Australia, there was a reduction of 700 deaths, despite 102 deaths from COVID-19. On the other hand, in Spain there was an increase of 45,800 deaths of which only 27,127 (60 percent) were recorded as due to COVID-19. In contrast, in Belgium there were an excess of 8,600 deaths but 9,487 were due to COVID 19.

This speaks to the challenge of determining the accurate case fatality rate for COVID-19. The actual number of deaths (both direct and indirect) is likely to exceed the 1.09 million currently reported. However, the actual number of cases is also highly likely to exceed the 38.4m currently reported, as many people with mild illness and were not tested. The case fatality rate using the Johns Hopkins data is currently 2.8 percent but estimates that consider the above issues, appear to suggest a rate closer to 1 percent. Nevertheless, this compares concerningly with the 0.1 percent for seasonal influenzas.

A more accurate figure is the death rate per million population reported by the WHO, using reported cases. There is a range of figures due to the effectiveness of political leadership and the management and the quality of the population health and health care systems. For Australia, 34 per million people have died from COVID-19, while in the USA, 612 per million people have died and in Spain 668 per million population have been recorded as dying form COVID-19.

Thus, if Australia were to lose control of this pandemic as occurred in the USA or Spain then we could expect at least 15,000 people to die in this country.

Across 21 wealthy nations, COVID-19 caused around 206,000 extra deaths almost equally split between men and women and overwhelmingly among the elderly (94 percent above the age of 65), according to a paper led by University College London in Nature Medicine. To put this in context, it's about the same number of deaths caused by cancer every year.

Covering most of the OECD, including Australia, the researchers used modelling to estimate historical country trends (since 2010-15) for all cause mortality in the absence of COVID-19 and then compared these to actual deaths during the pandemic. It turns out that ten countries, including Australia, had virtually no excess mortality at all. The largest increases of slightly more than one third were in Spain, England and Wales (37 percent and 38 percent), followed by Belgium, Italy and Scotland. In fact, across all 21 nations, it turns out that all-cause mortality was 23 percent higher than COVID-19 mortality, meaning that people have ended dying more from things other than COVID-19, either because lockdown caused economic shock or else the health system has been diverted from its usual business.

This begs the question of whether harsh lockdowns like the Victorian response did its job or was simply a cause of greater pain and mortality itself. Sweden, which eschewed lockdowns altogether, and even made social distancing voluntary, did much better than the worst-hit nations but not orders of magnitude better than Australia. I'd say the next step in this research is to replicate the findings within Australian states, and one that will likely challenge the lockdown, to examine the living impact of the pandemic like the Global Burden of Disease, where mental health and economic shocks and domestic violence are counted, all things rising in the background with over-strict lockdown policies.

There has been a lot of controversy about whether people are dying 'of COVID-19' or 'with COVID-19', particularly because most deaths have occurred in older people who are likely to have other health problems. Using 'excess deaths' to estimate the impact of the pandemic gets around this problem. The idea is to compare the number of deaths from all causes this year with the number of deaths over the same months in the last few years. The difference between the two numbers is the 'excess deaths'. If COVID is causing lots of deaths, even if it is undiagnosed or death is attributed to other factors, it will appear as excess deaths.

This is a very important paper. It shows that in the worst affected countries in Europe such as the UK, Italy and Spain, there have been more than 30 per cent more deaths than usual since the start of the pandemic. In contrast, Australia and New Zealand appear to have had no more deaths and possibly fewer than usual. Although sadly, more than 900 people have died from COVID-19 in Australia so far, this is being compensated for by fewer deaths from other causes (including, most notably, seasonal flu). We have avoided the dramatic levels of increased deaths seen in other western countries because of our rapid and strong response to the pandemic.

Disappointingly, the paper does not include data from the US, which of course has had the greatest number of cases and deaths from COVID-19. However, there is a website that reports excess deaths for many countries, although with less rigour than this peer-reviewed article. It suggests that the USA as a whole has had about 20 per cent excess mortality over the course of the pandemic.

The COVID-19 pandemic has impacted on the health and wellbeing of millions of individuals worldwide and is associated with considerable direct and indirect morbidity and mortality burden. Quantifying all-cause mortality is an important mechanism to understand the effects of major public health emergencies, and provides critical intelligence relating to local, international, and global capacity to respond.

In Victoria, Australia, the State Government Department of Health and Human Services has established robust surveillance systems to monitor mortality impacts directly and indirectly associated with COVID-19. These systems include integration of the Victorian notifiable disease dataset with the state’s death register (Victorian Death Index) to improve ascertainment of deaths attributable to COVID-19, and the monitoring of all-cause, respiratory and cardiovascular deaths.

Weekly mortality due to specific causes of death (respiratory diseases) was calculated for 2020 (to 30 September 2020) and was compared to an average number of deaths recorded over the previous 5 years (2015-2019). These average rates serve as a proxy for the expected mortality rate, providing an indication of excess mortality (1). Keyword searches were used to identify relevant respiratory diseases: pneumonia, influenza, chronic bronchitis, emphysema, asthma, and chronic obstructive pulmonary diseases.

Between 1 January 2020 and 30 September 2020, there were 798 deaths among laboratory-confirmed COVID-19 cases notified to the Department of Health and Human Services, of which 751 (94 per cent) were among people aged 70 years or older. Weekly mortality rates for respiratory causes were examined among this older cohort and are shown in Figure 1. The plot indicates that, despite the 751 COVID-19 related deaths, mortality due to respiratory causes is below expected levels in 2020. These findings are consistent with the findings of Kontis and others (2), demonstrating no detectable excess deaths in Australia.

During the winter months, mortality is typically higher among elderly Australians, which is thought to be attributable to infections with influenza and other respiratory viruses (3). However, in 2020, the incidence of respiratory infections seen in national sentinel surveillance systems has been extremely low (4). The reduced mortality rate may be attributable to restrictions that were implemented in Victoria to reduce local COVID-19 transmission."

Figure 1 (see image in multimedia on right hand side of page): Mortality rates due to respiratory causes for Victorians aged 70-79, 80-89, 90+ years. Dashed lines show the 2015-2019 average, while sold lines show mortality for 2020.  Major restrictions are shown.

References
1. Provisional mortality statistics Jan-June 2020, Australian Bureau of Statistics
2. Kontis 2020 https://doi.org/10.1038/s41591-020-1112-0
3. Muscatello 2013 https://doi.org/10.1371/journal.pone.0064734
4. Australian Influenza Surveillance Report https://www1.health.gov.au/internet/main/publishing.nsf/Content/cda-surveil-ozflu-flucurr.htm