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The true death toll of COVID-19
Estimating global excess mortality
On 30 January 2020 COVID-19 was declared a Public Health Emergency of International Concern (PHEIC) with an official death toll of 171. By 31 December 2020, this figure stood at 1 813 188. Yet preliminary estimates suggest the total number of global deaths attributable to the COVID-19 pandemic in 2020 is at least 3 million, representing 1.2 million more deaths than officially reported.
With the latest COVID-19 deaths reported to WHO now exceeding 3.3 million, based on the excess mortality estimates produced for 2020, we are likely facing a significant undercount of total deaths directly and indirectly attributed to COVID-19.
COVID-19 deaths are a key indicator to track the evolution of the pandemic. However, many countries still lack functioning civil registration and vital statistics systems with the capacity to provide accurate, complete and timely data on births, deaths and causes of death. A recent assessment of health information systems capacity in 133 countries found that the percentage of registered deaths ranged from 98% in the European region to only 10% in the African region.
Countries also use different processes to test and report COVID-19 deaths, making comparisons difficult. To overcome these challenges, many countries have turned to excess mortality as a more accurate measure of the true impact of the pandemic.
Excess mortality is defined as the difference in the total number of deaths in a crisis compared to those expected under normal conditions. COVID-19 excess mortality accounts for both the total number of deaths directly attributed to the virus as well
as the indirect impact, such as disruption to essential health services or travel disruptions.
COVID-19 global excess mortality
While 1,813,188 COVID-19 deaths were reported in 2020,
recent WHO estimates suggest an
excess mortality of at least 3,000,000.
Note: For the global estimate, a lower bound was calculated by extrapolating results from AMRO and EURO.
How are excess mortality estimates calculated and what are the main findings?
For countries with limited capacity to conduct real-time comparative analysis of observed and expected deaths, health estimates are an important in-filling mechanism. They can be calculated using a variety of statistical methods, from a minimalist approach to expert and statistical data synthesis. Regardless of the method, WHO estimates are always conducted in accordance with its Constitution and data principles and in close consultation with Member States, other UN agencies, and expert advisory groups to ensure a transparent and consensual process.
In collaboration with the United Nations Department of Economic and Social Affairs (UN DESA), and in accordance with the WHO Regulations for Scientific and Advisory Groups, WHO convened a Technical Advisory Group (TAG) on COVID-19 Mortality Assessment to develop harmonized methods for excess mortality and help determine the total number of direct and indirect deaths attributable to COVID-19. The COVID TAG is comprised of leading demographers, epidemiologists, data and social scientists and statisticians from a range of backgrounds and geographies.
The COVID TAG considered several statistical models and after assessing performance, interpretability and extensibility proposed a negative binomial regression model. The model predicts the number of total deaths for the year 2020 conditional on the population size and expected deaths for the year as well as a predicted mortality rate parameter. This rate parameter captures both the direct and indirect impacts of COVID-19 and is modelled using country-specific variables.
For 2020, excess mortality attributable to COVID-19 is defined as the difference between the total observed deaths for the year and those expected in the absence of COVID-19. The measure cannot be determined for all countries due to data gaps within some countries.
At the regional level, COVID-19 excess mortality estimates range from 1.34-1.46 million in the Region of the Americas to 1.11-1.21 million in the European Region in 2020. This represents about 60% and 50% more than reported COVID-19 deaths, respectively.
COVID-19 excess mortality estimates and reported deaths by WHO region, 2020
Note: The statistical model was developed using data from 50 (out of 53) countries in the European region and 15 (out of 35) countries in the region of the Americas to predict total death counts for countries for which observed deaths are not available. Country data included in the estimation process was not adjusted for under-reporting. The accuracy of the intervals is reliant on the accuracy of both the reported total death counts by countries and upon the modelled expected counts.
The challenges of data gaps
Significant data gaps exist in the African, Eastern Mediterranean, South-East Asian, and Western Pacific regions for which just over 360 000 total COVID-19 deaths were reported in 2020. Only 16 of the 106 Member States in these regions have sufficient data to make empirical calculations.
Without timely, reliable and actionable data we cannot accurately measure progress towards the health-related SDGs or WHO’s Triple Billion targets. Moreover, we cannot accurately measure the impact of the COVID-19 pandemic to better inform public policy and prepare for future health emergencies. According to WHO's World Health Statistics 2020 report, for almost one-fifth of countries over half of the SDG indicators lack recent, primary data. The availability of data also varies widely by income group and by indicator.
WHO is actively engaging with Member States to strengthen health information systems, particularly civil registration and vital statistics (CRVS), and improve data availability and quality. This includes targeted interventions to address the weakest areas identified by the SCORE (Survey, Count, Optimize, Review, Enable) global report, 2020, which showed for example that only 27% of countries have sustainable capacity to survey public health threats.
Innovation through partnership: World Health Data Hub
WHO's new World Health Data Hub will leverage digital solutions and technology partners to provide a more streamlined experience, integrating existing systems from across the three levels of the Organization to improve data collection, reporting and use. This includes the use of disaggregated data to more precisely address the inequalities that have been highlighted by the pandemic.
As key technology partners, Microsoft and Avanade are working closely with WHO to deliver this ambitious, end-to-end solution with a shared commitment to establish health data as a public good.
COVID-19 global excess mortality is one of the first use cases to demonstrate the power of the collaborative research environment offered by the Hub, with this work continuing as methods are refined and additional data is attained at the regional and country level.
Currently, WHO data engineers are leveraging state-of-the-art data pipelining services including Azure Data Factory to ingest and harmonize data from various sources into a modern Data Lake project repository. After data is ingested, WHO data scientists and Technical Advisory Group members are then able to build statistical and machine learning models together in R and Python in a cloud-based collaborative research environment. This significant upgrade in tooling enables faster and easier research collaboration with partners allowing researchers to work on the most up to date versions of data and code in a shared programming environment.
As the 'new home of health data’, the Hub will also provide a secure environment for countries to upload and validate their data while leveraging the latest technology in predictive analytics and data visualization for policymakers and the general public.
Opening remarks from Dr Tedros Adhanom Ghebreyesus at the first meeting of the Technical Advisory Group (TAG) on COVID-19 Mortality Assessment
Following the release of global and regional COVID-19 excess mortality estimates, the Technical Advisory Group will continue to refine the statistical models used in estimating excess mortality. WHO will actively engage Member States to improve the availability and quality of data and work with the TAG to produce country estimates.
Once created, preliminary country estimates will be shared through the World Health Data Hub country portal for official consultation. Country consultation is a cornerstone of WHO's data principles and commitment to uphold Member States’ trust in data. The country portal will provide a secure environment for Member States and WHO to exchange data and information across all three levels as part of the estimate verification and consultation process.
Access to the full COVID-19 excess mortality data set and methodology documentation will be available to download by the end of this year.
Looking ahead
The pandemic has stretched countries to their limits and exposed gaps that have too often been obscured. As of May 2021, we are not on track to meet any of WHO's Triple Billion targets, and COVID-19 threatens to throw us further off track.
But if we act with speed and scale, we can and will get back on track. Countries are ready to invest in their data and health information systems. The impact of health on all aspects of society – from economic activity to social and environmental factors – has never been clearer.
With good data we can ensure no one dies from a preventable, treatable illness. With good data we can reach vulnerable communities. With good data we can achieve the SDGs and leave no one behind.
COVID-19 has underscored the fact that we are all in this together, and no country is safe until all are. Effective data use depends on a shared commitment to data as a global public health good in line with WHO's data principles and data sharing policy, and this is at the core of the World Health Data Hub.
We must remember that behind every health figure is a person, a family – a life. Data on loss of life is no different.