Excess Mortality

Regular access to data related to an excess mortality in the population is important in order to be able to monitor seasonal flu and major outbreaks and pandemics with a view to comparisons in time and place. Excess mortality is the most reliable data for understanding the true significance of severity of each virus outbreak.

Due to the problems associated with the diagnosis of Covid-19 deaths with unreliable PCR tests and widely varying definitions of a Covid-19 death (e.g. in U.K. covid deaths are registered within 60 days of a positive COVID-19 test or where COVID-19 is mentioned on the death certificate) – European countries recommend monitoring the overall mortality and the so-called excess mortality with reporting at least once a week. Tracking all deaths provides a more comprehensive picture of the extent of mortality and enables comparisons in time and place.

During the three years 2008 to 2011 multiple partners from a number of European countries were engaged in developing a coordinated approach to doing exactly this: real-time standardised mortality monitoring across Europe (read more here). What became known as the EUROMOMO network includes today 25 countries that report weekly mortality to the Serum Institute in Copenhagen. Graphs showing the pooled weekly total number of deaths in the data-providing EuroMOMO partner countries and subnational regions, all ages and by age groups are presented from 2016 to the present.

European Mortality Monitoring Project -EUROMOMO

Mortality figures could show that there was an increase in excess mortality and the weekly reporting on excess mortality from 25 European countries in Europe to the Serum Institute in Copenhagen (EuroMomo). From the graph we see a rapidly rising and then declining “spike” from an inconspicuous 57,000 deaths to 90,000 deaths and then returned to 57,000 deaths (34%) within 12 weeks (week 7 to 19, 2020).

Some have argued that parts of this “spike” wave seen in the spring of 2020 were due to a lack of treatment of patients outside hospitals in the early stages of the disease before hospitalisation around the world and where the threshold for use of medical respirators in intensive care units was low in part driven by a thought of preventing infection risk to health personnel through closed ventilation. Mortality in such patients was over 80%

From EuroMomo it can be seen that in the weeks 12 to 22 – 2020 England experienced an increase in excess mortality to just under 40% with Spain slightly over 40% followed by Italy, Scotland and the Netherlands by just under 20%. Sweden, Northern Ireland and Switzerland had an excess mortality rate of around 10% in the same period. Some areas in these countries experienced special pressure on hospital capacity, such as in northern Italy and parts of England but not close to the dismal numbers that came from the modelling of Neil Ferguson of Imperial College, London.

In Nordic countries, with the acceptation of Sweden there has been no indication of excess mortality during 2020-21 compared to to the three preceding years. Norway showed a marked decrease in excess mortality With a hitherto registered total mortality associated (e.g. Norway) with Covid-19 of under 0.01% from the beginning of March 2020 until 23 March 2021 .

Excess Mortality from latter half of 2016 to present in Denmark, Finland, Norway and Sweden.

Monitoring Project -EUROMOMO
Excess mortality in Sweden compared to other nordic countries

Some argue that the reason for the relative substantial increase in excess mortality in Sweden compared to their nordic neighbours was the fact that Sweden was one of the few EU countries that did not undertake any restrictive policies of lockdown or other mandated policies like mask wearing. Despite this policy Sweden still had a relatively modest excess mortality compared to countires like Northern Ireland and Switzerland.

Sweden mostly relied on voluntary measures focused on good hygiene and targeted measures that in large kept schools, restaurants and shops open – an approach that spared the economy from much of the hit suffered elsewhere in Europe.

The Preliminary data from EU statistics agency Eurostat showed Sweden had 7.7% more deaths in 2020 than its average for the preceding four years. But of countries that opted for several periods of strict lockdowns, such as Spain and Belgium, had excess mortality of 18.1% and 16.2% respectively.

Twenty-one of the 30 countries with available statistics had higher excess mortality than Sweden. However, Sweden had higher excess mortality than its Nordic neighbours, with Denmark registering just 1.5% excess mortality and Finland 1.0%. Norway had no excess mortality at all in 2020.

To put this in a broader societal and historical perspective we need to look at both the total death rates over a longer period of time and more importantly at the age adjusted (age standardized ) death rates for this same period.

In 2020, adult mortality rate for Sweden was 7.35 deaths per 100 population. Over the last 46 years, adult mortality rate of Sweden was declining at a moderating rate to shrink from 14.49 deaths per 100 population in 1975 to 7.35 deaths per 100 population in 2020. If we loook at Swede’s total number of deaths since 2011 we see that the overall numbers of deaths was slightly larger in 2020 than the reported overall deaths for 2016 and 2017.

Age adjusted (standardized death rates)

To compare the relative health status of different population groups, the population’s age distribution needs to be taken into account, because death rates for most diseases generally increase with age (Curtin & Klein, 1995). “Age-standardized mortality rates adjust for differences in the age distribution of the population by applying the observed age-specific mortality rates for each population to a standard population” (World Health Organization, 2020b). In other words, this technique allows comparison between populations with differing age profiles. The populations are thus given the same age distribution structure, so that those differences in mortality which are not due to the ageing of the population can be highlighted.

At a national level, there are age-standardised mortality rates higher than the Nordic average (883.0) in Greenland (2,449.2), Denmark (988.6), and Finland (921.7). These statistics show the number of deaths per 100,000 of the population in each country, after removing variations brought about by differing age structures between the three countries. In the calculation of age-standardised mortality rates, we used the European Standard Population in 2013. It is observable that age-standardised mortality rates are lower in capital regions and large cities in all Nordic countries, suggesting a lower level of ill health in these regions. There is a high variation of mortality rates between municipalities in Finland, Iceland, Norway, and Sweden. The municipalities having the highest mortality rates tend to be economically disadvantaged, with lower levels of disposable household income and a smaller proportion of people having attained tertiary education.

A study from the Norwegian Institute of Health FHI that analysed age adjusted trends in mortality between Norway and Sweden in the period 2010 to 2020. The study found that in 2020 there were very small differences between Norway and Sweden for age adjusted deaths of all causes and in both countries there were fewer reported deaths due to respiratory infections than expected,

For the differences observed between countries related to excess mortality and seasonal influenza like diseases reflect the differences between countries of numerous variables including physiography, population composition and distribution between city and country, ethnic variations, size and composition and distribution of the country’s immigrant population, organisation of health and care services, elderly care etc. must be tale into account. These individual factors together become the most important factors that affect variations in morbidity and mortality from each known or new viral outbreak in a population and as reflecteted in variations in age standardized mortality rates between countries.

As in Sweden, both in the UK and US – after one year of observation – the conclusion was the excess mortality could be compared to what was observed in 2017. The Centers for Disease Control and Prevention (CDC) on February 20, 2021 reported that 376,504 deaths were attributed to COVID-19 in the United States in the calendar year 2020. It is worth noting that this figure corresponds well below the estimated total number of deaths of 401,000 in excess the United States in 2017.

The comparison is more striking when comparing lost life years. Goldstein and Lee estimate that the average loss of life for a person who dies from COVID-19 in the United States is 11.7 years. Multiplying 377,000 decedents by 11.7 y lost per decedent gives a total of 4.41 lost life years from COVID-19 in 2020, which is then only a third of the 13.02 million life years lost to excess mortality in the US in 2017. This is due to a significantly higher average age for COVID-19 deaths in 2020 than the average age for excess mortality in 2017 due to flu-like illness.

In contrast to the Spanish flu, where the average age of those who died of influenza in the UK was 28 and with a hundred times greater mortality than what we see with Covid-19 – the average age for those who died with Covid-19 is 80 and for women 84 (UK Office of National Statistics). This is a higher age than average life expectancy in parts of the UK.

It must therefore be emphasized in this context that Covid-19 is an infectious disease that affects the oldest in the population with a significant increase in the risk of a fatal outcome for those over 85 years of age compared (7900 times) compared to the age group 5-17 who is more than for influenza disease.

Mortality rate (per 100,000 population) in laboratory-confirmed cases of COVID-19 by age and sex, from week 27 onwards in England.

ONS Confirmed Covid-19 Deaths in England

If one looks at monitoring the excess mortality in England and Wales in the period 1920 to 2020, the mortality rate in the spring of 2020 seems to be almost as great as in the war years 1940-45. Excess mortality in England and Wales from 1920 to 2020 (incl. November 2020) gives the impression that the mortality associated with the first wave associated with Covid-19 to be significant.

Monthly analysis of mortality from the UK Office of National Statistics (ONS)

But when one takes into account the age and size of the population, the excess mortality, after age adjustment, has shown a steady decrease and so the age adjusted mortality rate for 2020 is not greater than what was seen in the preceding years and much less than was seen in the years up to te millennium. This understanding is important in assessing the so-called “pandemic” severity in relation to measures that are implemented.

UK Office of National Statistics (ONS)