ABSTRACT
Objective Well-established mortality ratio methodology can contribute to a
fuller picture of the SARS-CoV-2/COVID-19 burden of disease by revealing
trends and informing mitigation strategies. This work examines respective data
from Germany by way of example.
Methods Using monthly and weekly all-cause mortality data from January
2016 to June 2020 (published by the German Federal Statistical Institute) for
all ages,<65 years and≥65 years, and specified for
Germany’s federal states, we explored mortality as sequela of COVID-19.
We analysed standardized mortality ratios (SMRs) comparing 2020 with
2016–2019 as reference years with a focus on trend detection.
Results In Germany as a whole, elevated mortality in April (most
pronounced for Bavaria) declined in May. The states of Hamburg and Bremen had
increased SMRs in all months under study. In Mecklenburg-Western Pomerania,
decreased SMRs in January turned monotonically to increased SMRs by June.
Irrespective of age group, this trend was pronounced and significant.
Conclusions Increased SMRs in Hamburg and Bremen must be interpreted with
caution because of potential upward distortions due to a “catchment
bias”. A pronounced excess mortality in April across Germany was
confirmed and a hitherto undetected trend of increasing SMRs for
Mecklenburg-Western Pomerania was revealed. To meet the pandemic challenge and
to benefit from research based on data collected in standardized ways, national
authorities should regularly conduct SMR analyses. For independent analyses,
national authorities should also expedite publishing raw mortality and
population data, including detailed information on age, sex, and cause of death,
in the public domain.
Key words
SARS-CoV-2/COVID-19 - SMR - excess mortality - epidemiology - surveillance
