Global consortium publishes findings on all-cause mortality during COVID-19 pandemic in 22 countries

A global consortium representing 27 institutions has published findings comparing mortality in the previous five years to deaths between January and August 2020 in the first wave of the pandemic. Their results show that some countries experienced excess all-cause mortality, while other nations had minimal or even decreased excess mortality. Data from the UK shows substantial excess mortality in the research period.

Led by the University of Nicosia (UNIC) in Cyprus, the research by the Covid-19 Mortality (C-MOR) Consortium has been published in the International Journal of Epidemiology. The consortium consists of partners in 22 countries across the globe, including the UK, USA, Brazil, Australia and multiple European countries. The analysis of UK data was led by researchers from St George's, University of London.

The group assessed data on weekly or monthly all-cause mortality from each of the countries included, comparing data from January to August 2020 with baseline data from 2015 to 2019. They used two methods; comparing the difference in observed mortality in 2020 with the 2015 to 2019 average, as well as the difference between the observed 2020 mortality with the expected number of deaths.

The results from the study show that several of the 22 countries included had increased all-cause excess mortality (Brazil, England, France, Italy, Northern Ireland, Scotland, Spain, Sweden, the USA, and Wales). Some of the countries included recorded reduced excess mortality (Australia, Denmark, and Georgia), while other countries drew insignificant findings.

The analysis from the UK demonstrated that the country was found to have particularly elevated all-cause excess mortality. England and Wales were shown to have 53,869 excess deaths, Scotland, 3,911 and Northern Ireland, 825.

Professor of Epidemiology at St George's, University of London, Julia Critchley, said: "Our data analysis shows that the UK experienced a stark increase in excess mortality in the first wave of the pandemic.

"There is an imperative to learn the lessons from the actions that were taken when Covid-19 first entered the country, but with a delay to the independent public inquiry, it could be a long time before we have definitive answers as to why the UK has experienced so many more deaths than other comparable countries. In the meantime, further research is needed as the pandemic continues, so that we can better assess measures taken in different countries with different rates of vaccination and disease burden."

This study represents the first published analysis on excess mortality for six of the included countries (Cape Verde, Cyprus, Georgia, Ireland, Slovenia, and Ukraine).

This is also one of the few studies to examine excess sex-specific mortality. While some countries did not show significant changes in excess mortality across the total population, in Israel and Ukraine, there was increased mortality among males, whereas in Ireland there was increased mortality among females. Further analyses are required to try to better understand reasons for these sex-differences internationally.

Another unique variable assessed in this study was governmental restriction measures. The authors note that the countries with increased excess mortality tended to have limited or delayed control measures.

These results represent one of the largest and most expansive studies of mortality from the pandemic that predominantly utilised national and primary sources, as opposed to publicly available datasets.

As we face this politicised pandemic, the consortium is actively collecting accurate and timely surveillance data. We will not only continue to monitor excess deaths but will also begin to study the morbidity burden from Covid-19. These analyses will help us to better understand and minimize the multi-dimensional health effects of the virus."

Dr Christiana Demetriou, Assistant Professor of Epidemiology and Public Health, UNIC Medical School

The consortium are now collating and analysing data for the whole of 2020 in order to examine these trends over a longer period of time, as the pandemic progresses.