Recently, the World Health Organization (WHO) released new estimates of excess mortality resulting from the COVID-19 pandemic, based on the work of a Technical Advisory Group (TAG) comprised of leading demographers, epidemiologists, data and social scientists and statisticians. This blog will summarize this work and charts the impacts on countries in Asia and the Pacific
What is excess mortality?
Excess mortality is a term that refers to the number of deaths from all causes during a crisis, such as the COVID-19 pandemic, above and beyond what is expected under ‘normal’ conditions. Looking at those excess deaths is then used to understand the direct and indirect impacts of the COVID-19 pandemic.
These excess deaths include deaths attributable directly to COVID-19 as well as indirect deaths through impacts on health systems and society, minus any deaths that would have occurred under normal circumstances but were prevented due to pandemic-related changes in social conditions and personal behaviours. Thus, estimates of the excess mortality associated with the COVID-19 pandemic include deaths from all causes and may, in some cases, be lower than those usually expected due to, for example, a reduction in deaths from road traffic accidents or seasonal influenza. In certain locations, these estimates may reflect excess deaths associated with other crises such as disasters, or conflicts. That said, evidence shows that excess deaths are a good indicator of COVID-19 deaths, with the disease directly causing most of these deaths.
How has excess mortality been estimated?
Mortality data to calculate actual deaths in real-time are available in only a subset of countries where civil registration and vital statistics (CRVS) systems are functioning effectively. Many countries are not able generate and collect mortality data in a timely manner and these data gaps mean that excess mortality cannot be directly reported for all countries. In those countries where data has been unavailable and/or incomplete, the TAG has established a methodology to model these excess deaths, generally accepted by most countries, although it should be noted that a few countries have expressed reservations about the methods used for the modelled estimates.
Out of the 50 member States and associate members in the ESCAP region with estimates reported by the TAG, most (34) had modelled estimates, highlighting the deficiencies in civil registration of deaths in many countries in the region.
Total excess deaths
Globally, there were nearly 15 million excess deaths which is about 13 per cent above those expected. Countries in the ESCAP region accounted for more than half of these deaths, with 8.2 million excess deaths. Most of the excess deaths in the region were accounted for by just three countries: India (4.7 million), Russian Federation (1.1 million) and Indonesia (1 million), with these numbers considerably higher than the official COVID-19 numbers reported.
Excess deaths relative to normally expected deaths
Obviously, countries with larger populations will tend to have higher numbers of deaths, all else equal. As a percentage above normal, Armenia stands out as having the highest relative increase in mortality at about nearly 40 per cent above that normally expected, followed by Azerbaijan and the Russian Federation. However, the data from Armenia are likely to have been affected by the impact on the male population of the conflict in 2020 and should be considered with caution with respect to the COVID-19 pandemic. Despite India having the highest number of excess deaths, its large population means that the relative increase is lower than other countries at 9 per cent.
There are several countries where estimates show negative excess deaths. This reflects deaths that would have happened in the absence of the pandemic but were averted due to public health measures taken to deal with the pandemic often offsetting any deaths due to COVID-19.
Figure 1: Percentage of excess deaths above normal
Modelled excess deaths as a proportion of Covid-19 reported deaths
As mentioned, it is expected that most excess deaths during 2020 and 2021 occurred as direct result of COVID-19 even though some deaths may result from indirect causes. Therefore, excess deaths should not deviate greatly from those as a direct result of COVID-19. However, in some cases, the modelled estimates were almost 10 times greater than the reported COVID deaths as Figure 2 shows. This demonstrate the deficiencies in CRVS systems, particularly with respect to the recording of causes of death which is notably weak in the region.
Figure 2: Average excess deaths vs reported COVID-19 deaths, countries with more than 20,000 average excess deaths (2020 and 2021 in Asia-Pacific)
The modeled excess deaths in India exceeded the reported COVID deaths by a factor of almost 10, indicating the difficulties of the civil registration system to register all deaths and record causes of death during the peak of the pandemic wave. While the absolute numbers were particularly high, given the large population in India, the modelled deaths exceeded the reported COVID deaths by a factor of 104 in Uzbekistan. Moreover, modelled deaths exceeded the reported Covid deaths by eight times in Pakistan and seven in Indonesia.
Uncertainty in the modelled data
Due to the modelling involved, the estimates, while the best possible right now, have a range of uncertainty per country and that level of uncertainty is directly related to a country's CRVS capacity and data quality and availability. If the uncertainty bounds are larger, this indicates that there is less quality data available and therefore, a corresponding greater degree of uncertainty.
These ranges in uncertainty serve to highlight the ongoing need to strengthen national CRVS systems and reporting of causes of death to help improve data availability and ensure all deaths are counted. ESCAP has been supporting work to strengthen these systems to improve the current response and prepare for any future crises.
More information about ESCAP work on CRVS: https://getinthepicture.org/
More information on global excess deaths associated with the COVID-19 pandemic: https://www.who.int/news-room/questions-and-answers/item/global-excess-deaths-associated-with-the-COVID-19-pandemic