gms | German Medical Science

Background and status of (inter)national research: Prior to vaccination approval, residents of nursing homes were at increased risk for severe disease progression with COVID-19 due to their age and prevalence of pre-existing conditions.

Research question and objective: The aim of the study was to find out whether there was an excess mortality among long-term care residents in Styria in the year 2020 and whether excess mortality was higher than in the Styrian population outside of nursing homes.

Method or hypothesis: To detect a potential excess mortality, the weekly numbers of deaths in the year 2020 were compared to the expected numbers of deaths using the smoothed mortality rates from the years 2015 to 2019 as baseline values. Three different scenarios were used to predict the expected numbers of deaths: The weekly median mortality rate, based on the years 2015 to 2019, was applied in the main analysis; the first and third quartiles were used as sensitivity analyses. Excess mortality was calculated for Styrian nursing home residents as well as for the Styrian population outside of nursing homes.

The analyses are based on routine data, which were provided by the local administration of the federal state of Styria and from the Federal Institution Statistics Austria.

Results: In nursing home residents, the weekly numbers of deaths started to exceed the expected numbers of deaths in calendar week 11 of 2020 and returned to the expected level at around calendar week 19 (“1st wave”). The second wave started at around week 35 and reached its peak in week 49.

Overall, the total excess deaths in 2020 reached 1.155 in Styrian nursing homes. All age groups and both sexes were affected, but men, aged 85 and above, showed a much higher excess mortality rate than all other groups. A sensitivity analysis shows that the results depend only slightly on the model assumptions made.

In the general population outside of nursing homes, men at all ages and women in the age group 75–84 years showed minor excess mortality. However, the total sum of deaths in the year 2020 was even below the expected number of deaths, if only the Styrian population outside of nursing homes is considered.

Discussion: The study showed, that in the first year of the COVID-19 pandemic, there was a substantial increase in the number of deaths among long-term care residents in Styria compared to previous years. Interestingly, no excess mortality could be observed in the Styrian population outside of nursing homes. However, this does not mean that there were no COVID-19-associated deaths in the Styrian general population. Rather the unexpected lower mortality may be explained by the instruction of distance and hygiene concepts, as well as behavioural changes during the pandemic, which led to a reduction of deaths from other causes, such as influenza or accidents.

Appeal for practice (science and/or care) in one sentence: In the case of pandemics, there is a need for risk-adjusted protective measures for vulnerable subgroups.