Increased Mortality in Germany and in the Individual German States During the SARS-CoV-2/COVID-19 Pandemic in 2020 and 2021

Standardized mortality ratios are—with continuous comparisons in high temporal and spatial resolution—well suited to contribute to the analysis of the course of mortality attributable to the COVID-19 pandemic as a gross effect (1). Our aim was to describe mortality in Germany and the 16 German federal states over a period of 24 months in 2020 and 2021.

Methods

The analysis included mortality data for Germany and the German states for 2020 and 2021 and compared them to data for the period 2016 to 2019 sourced from the German Federal Statistical Office (data provided as of 1 February 2022). The outcome measure was mortality which we analyzed for the combinations of gender (total, male, female) and age (total, <65 years, ≥65 years) for the period from January 2020 to December 2021. The calculated effect measures were simplified standardized mortality ratios (SMRs) with extended 95% confidence intervals (extended = random-effects approach) per week and month which we calculated as the ratio of the number of deaths in 2020 and 2021 and a mean (arithmetic and geometric, respectively) of the number of deaths in the period 2016 to 2019. For detailed information about these methods and the statistical software used for data analysis see (2).

Results

In 2021, 1 019 809 deaths occurred in Germany. On the basis of the period 2016 to 2019, the number of expected deaths (geometrically) was 933 367.3, corresponding to an SMR of 1.09 (95% confidence interval: [1.07–1.11]). In 2020, there were 985 572 deaths in Germany, corresponding to an SMR of 1.06 [1.04–1.08]. Subgroup analyses (men, women, ≥65 years, <65 years as well as their combinations) also revealed an increased SMR in 2021 compared to 2020. We encountered this finding in all German states (except Bremen). Men (2021: SMR = 1.12; 2020: SMR = 1.07) had a higher SMR than women (1.07; 1.04); similarly, older persons (≥ 65 years: 1.10; 1.07) had a higher SMR than younger persons (<65: 1.05; 1.00). The highest SMRs among men aged ≥ 65 years were found in Saxony-Anhalt (1.20; 1.08), Saxony (1.24; 1.19), Brandenburg (1.26; 1.15) and Thuringia (1.27; 1.09).

The SMR curve for Germany (Figure 1) shows that after March 2021 there was an upward trend until December (again in both age groups and sexes as well as their respective combinations).

Figure 1

Relative mortality (SMR point estimate with 95% confidence interval, geometric) considering all causes of death for people in Germany from January 2020 (1) to December 2021 (24)

Standardized mortality ratios differed across the 16 German states—in some cases significantly—over time (Figure 2). In Mecklenburg-Western Pomerania, for example, there has been an almost continuous increase in SMR since January 2020 (with a noticeable decline only intermittently from January to March 2021), which we had already pointed out earlier for the period up to June 2020 (1). In 2021, Saxony, Brandenburg and Thuringia again showed significant increases above the national average. North Rhine-Westphalia was below and Bavaria in 2021 again above the national average of the SMR curve in the winters of 2020 and 2021.

Figure 2

Relative mortality (SMR, geometric) within Germany and its 16 federal states from January 2020 (1) until December 2021 (24) considering all causes of death

Discussion

The increase in SMR of about 6% in 2020, climbed to 9% in 2021. One contributor is the increased SMR in January 2021 (in January 2020, Germany had not experienced any COVID-19 deaths), another the trend increase in SMR curves after February 2021 which was observed in all age groups and in both sexes. Seasonal effects with increased SMR in the winter months are obvious.

Comparing the course of the curve in Germany with the course of occupancy rates of adult ICU bed from January to December 2021 obtained from the DIVI ICU registry of the German Interdisciplinary Association for Intensive Care and Emergency Medicine (DIVI, Deutsche Interdisziplinäre Vereinigung für Intensiv- und NotfallmedizinDeutsche Interdisziplinäre Vereinigung für Intensiv- und Notfallmedizin), a positive ecological correlation is noted, even decreases in occupancy rates from January to March and from May to July 2021 can be related to changes in the SMR curves. Thus, the SMR courses show an ecological correlation with the COVID-19 burden on adult intensive care units.

The increase in SMR curves observed from March 2021 onwards coincides with the period when a mortality-reducing effect of the vaccinations could have been expected (3). For the most part, the SMR curve observed in 2021 appears to be ecologically attributable to COVID-19; however, no gross effect of the vaccinations on mortality was found.

That no decrease in excess mortality was observed despite the vaccinations can be a result of certain factors—such as less contact restrictions and a more risky behavior – that outweigh vaccinations in their effects on mortality. Furthermore, an inadequate level of vaccination rates could also be the cause: An ecological study on 192 countries concludes that 80 % of the population should be vaccinated to achieve a significant reduction in case fatality rate (4).

For information about the limitations of our analysis see (1). We emphasize that the usual standardization by five-year age groups was not performed. However, demographic shift plays only a minor role in the comparison of adjacent periods; especially, changes in the SMR curve that occur during one year are almost unaffected. Our approach is not intended to measure the mortality effect of COVID-19 on the population; instead, we present a description of the gross effect. Such a gross assessment of mortality in 2020 and 2021 is of epidemiological and social interest, given the significant changes in public health measures (mandatory mask-wearing, closure of businesses, etc.) that occurred in this period compared to the reference period from 2016 to 2019.

Overall, the significant differences in mortality between the German federal states during this 24-month period demonstrate the necessity of evaluating mortality during a pandemic with a high degree of differentiation—by causes of death, gender and age and with high resolution in time and space. Vaccinations remain imperative (5).

Peter Morfeld, Barbara Timmermann, Philip Lewis, Thomas Erren

Acknowledgement

Barbara Timmermann was supported by the “Köln Fortune” program of the Faculty of Medicine, University of Cologne, Cologne, Germany.

Conflict of interest statement
The authors declare that no conflict of interest exist.

Manuscript received on 14 February 2022, revised version accepted on 21 April 2022

Cite this as:
Morfeld P, Timmermann B, Lewis P, Erren TC: Increased mortality in Germany and in the individual German states during the SARS-CoV-2/COVID-19 pandemic in 2020 and 2021. Dtsch Arztebl Int 2022; 119: 560–1. DOI: 10.3238/arztebl.m2022.0208

References

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2. Morfeld P, Timmermann B, Gross VJ, Lewis P, Erren TC: COVID-19: How did mortality change? – Mortality of women and men in Germany and its federal states until October 2020. Dtsch Med Wochenschr 2021; 146: 129–31.

3. Liang LL, Kuo HS, Ho HJ, Wu CY: COVID-19 vaccinations are associated with reduced fatality rates: evidence from cross-county quasi-experiments. J Glob Health 2021; 11: 05019

4. Coccia M: Optimal levels of vaccination to reduce COVID-19 infected individuals and deaths: a global analysis. Environmental Research 2022; 204: 112314

5. Haas EJ, Angulo FJ, McLaughlin JM, et al.: Impact and effectiveness of mRNA BNT162b2 vaccine against SARS-CoV-2 infections and COVID-19 cases, hospitalisations, and deaths following a nationwide vaccination campaign in Israel: an observational study using national surveillance data. Lancet 2021; 397: 1819–29