Changing socioeconomic inequalities in the incidence and case fatality rates of COVID-19 in Germany, March 2020 through May 2022: an ecological study.

backgroundSocioeconomic disparities in COVID-19 burden were widely observed during the pandemic's early waves, including in Germany, but studies on whether these inequalities have persisted or changed as the pandemic progressed are lacking.

methodsWe used an ecological study design to assess the relationship between a range of demographic, socioeconomic, and healthcare-related predictors and COVID-19 impact in Germany. Specifically, we fit generalized additive models to cumulative, district-level (n = 400) COVID-19 incidence and case fatality rates (CFRs) for each of the first five pandemic waves, which covered the period from March 2020 through May 2022.

resultsWe find that associations between socioeconomic deprivation and COVID-19 impact evolved over time. Specifically, districts with higher levels of deprivation experienced lower incidence initially, but higher incidence beginning in the second half of wave 1 and persisting through wave 3. Meanwhile, more deprived districts experienced higher CFRs initially as well as during waves 3 through 5, but lower CFRs during the second half of wave 1. Finally, during the first four waves, we find that district-level CFRs scaled superlinearly with incidence, suggesting that the risk of death increased with incidence. This relationship was particularly strong during the first pandemic wave.

conclusionsThe association between socioeconomic position and COVID-19 impact in Germany has been complex, with patterns changing in intensity and direction over time. Continued monitoring of socioeconomic inequalities in COVID-19 impact, in particular at the individual level, is needed to better understand if and how inequalities continue to persist. Such monitoring will be instrumental in informing more equitable control strategies.