Mortality in Corona: How age & Co. influence the risk of death

The mortality rate for COVID-19, i.e. infections with the coronavirus, depends on various factors. Among other things, age and the respective country, but also gender, previous illnesses or vaccination status play a significant role, so the information on mortality from Corona can vary greatly. Why is that? How do you calculate the death rate, and what is the average mortality rate for COVID-19? In the following, we give you an overview of the most critical factors.

How does coronavirus determine mortality?

There are several ways to calculate the risk of death from COVID-19:

1. Infection fatality rate:  This is the ratio of deaths to the total number of people infected, including estimates of the number of unreported cases for the number of infections.
2. Proportion of deceased cases: The number of deceased is set about the reported cases. This number can be influenced by the type of test and reporting system in question.
3. Mortality:  The proportion of people who show symptoms of an infection, i.e. who contract COVID-19 and die, is considered here. However, it is difficult to get exact figures because the number of people with symptomatic COVID-19 courses is not precisely recorded.

This distinction already shows that it can be challenging to quantify the death rate from COVID-19 accurately. Below, you will find out which other factors influence the mortality rate data.

 

How high is the mortality rate from Corona?

 According to figures from Wuhan, China, published at the beginning of the pandemic, the mortality rate at that time was 1.4 per cent. However, if you only looked at people with a symptomatic infection, the lethality was 4.5 per cent. In addition, mortality was reported differently for different age groups. People over the age of 60 had the highest risk of dying from a coronavirus infection. In the evaluation, their risk of death was five times higher than that of 30 to 59-year-olds. However, it must be noted that this information is based on the data from Wuhan and was partially extrapolated. 1

A global mortality rate of 2.1 per cent is now reported. This means the ratio of deaths to reported cases of infection. For Germany, this figure is 1.9 per cent (as of 12/2021). 2

According to the Robert Koch Institute, including estimates of unreported infections, the infection mortality rate is significantly lower: Around 0.4 to 0.9 per cent (as of 11/2021). According to calculations by the Robert Koch Institute, the mortality rate for the first wave of the pandemic is around 6.2 per cent. 3

Corona: mortality by age

About 85 per cent of all those who died from or with Corona in Germany were 70 years old or older. Only about 1.5 per cent were younger than 50 years (as of 01/2022). 4 Most of them suffered from previous illnesses.

According to a meta-analysis of data from Germany published in December 2020, the risk of death by age (for unvaccinated and unvaccinated people) is as follows: 5

• at ten years: 0.002 per cent
• at 25 years: 0.1 percent
• at age 55: 0.4 percent
• at age 65: 1.4 percent
• at age 75: 4.6 percent
• at 85 years: 15 per cent
• from 90 years: 25 per cent

According to other calculations, the risk of dying from a coronavirus infection increases tenfold every 20 years of life. This would mean that the risk of death in a 60-year-old would be 100 times higher than in a 20-year-old.

Nevertheless, younger people without previous illnesses are also repeatedly affected by severe courses and die. There are also some child deaths.

People with a severe course of COVID-19 die on average about three weeks after the first symptoms appear.

 

Why do so many older adults die from SARS-CoV-2?

It is rather unusual that most of the fatalities are in the over-60 age group. In other pandemics, such as the flu, young children are usually severely affected as well. Older people, in particular, are dying because it is a relatively new virus.

With increasing age, the immune system can no longer react as quickly and precisely to new viruses. The virus and the innate immune system attack and destroy the body’s tissues because the targeted immune response is delayed. Many older people also have previous illnesses that also promote a severe course of infection.

Death rates by country

Mortality figures vary widely between different countries. In Germany, the death rate is 1.9 per cent (as of 12/2021). In India, it is given as only 1.3 per cent. In Mexico, on the other hand, it is 8.3 percent. 2 At times, for example, in Italy, it was even in the two-digit range.

Possible reasons for these significant deviations include medical care and the different age structures in different countries. However, how much is tested also plays a significant role. If only people with symptomatic courses are tested, many people with asymptomatic courses are not recognized as infected. As a result, there is a higher number of unreported cases. The percentage of severe and fatal courses increases, and the death rate is higher than in countries where infected people without symptoms are also recorded.

On the other hand, there can also be a high number of unreported deaths if there is little testing and the cause of death is mistakenly attributed to other than COVID-19 infection.

Other factors influencing the mortality rate

According to data from the Robert Koch Institute, social differences can also influence mortality. In Germany, for example, the death rate was 50 to 70 per cent higher in socially disadvantaged regions during the second wave of infections.

Gender can also have an influence. Fifty-three per cent of the deceased in Germany were men.

In addition, previous illnesses increase the risk of a severe course and, thus, the mortality rate. The risk of death from dementia is twice as high, and after an organ transplant, it is even four times higher than usual. In this article, we present other risk groups for a severe course.

Being vaccinated against COVID-19  also has a significant impact on the risk of death. Although there are deaths despite vaccination, the total number of vaccinated people dies significantly less than the unvaccinated. Older people with previous illnesses are usually affected, as a Scottish study found. 6

In November 2021, the Texas Health Department released data on the risk of death for vaccinated people from mid-January to early October 2021. According to this, the risk of dying from Corona was 40 times higher for unvaccinated than for vaccinated people. According to the data, the risk of contracting Corona was 45 times higher than after a complete vaccination. 7

 

Germany-wide analysis of lethality

The first Germany-wide analysis of lethality was published in July 2020. About a fifth (22 per cent) of those infected with COVID-19 who were admitted to German hospitals between the end of February and mid-April 2020 have died. The mortality rate for those infected with ventilation was 53 per cent, while that of those without ventilation was significantly lower at 16 per cent. A total of 17 per cent of those affected were ventilated.

The data of around 10,000 people with a confirmed COVID-19 diagnosis from 920 German hospitals were evaluated.

mortality over time

In another retrospective analysis of hospitalized COVID-19 cases, the all-cause mortality was 18.8 per cent. Regarding ventilation, the lethality was given as 38.8 per cent. Mortality fell over the period under review from 20.7 per cent to 12.7 per cent, which can be understood as an indication of the improved medical treatment of the sick. Data from 1,300 people in 14 German university hospitals was analyzed from January 2020 to September 2020.

This also shows that mortality can change over time. Factors such as improved therapy or a high vaccination rate (which makes severe courses less common) can contribute to reducing mortality. Viral mutations, on the other hand, can cause death rates to increase (or decrease).

Cause of death – died of or with Corona?

The suspicion is repeatedly voiced that people die not from but from Corona – this means that they die, for example, due to any previous illnesses. According to experts, this is not correct because the majority of the deceased examined died directly as a result of COVID-19.

Investigations have shown that most of the dead had massive damage to blood vessels, pronounced thrombosis (especially in the pulmonary vessels) and a particular form of vascular formation. This made it possible to prove that 82 per cent of the autopsied deceased had died of and not with COVID-19.

 

What does excess mortality mean?

Excess mortality is a number that tells you how many more people died on average in a given period compared to other periods. The term describes a higher death rate than usual. During an influenza epidemic, for example, the number of deaths usually increases so that the difference – the excess mortality – can be used to estimate how many deaths are due to such an influenza epidemic.

The deaths as a result of COVID-19 are also reflected in the excess mortality – in Germany, the various waves of the pandemic led to a correspondingly higher number of deaths. Excess mortality is considered suitable for comparing deaths internationally since factors such as different test strategies or counting methods are irrelevant.