Excess mortality during the first 2 years of the COVID-19 pandemic (2020-2021) in the Netherlands: Overall and across demographic subgroups.

Objectives: The overall impact of the COVID-19 pandemic on mortality can be estimated by the assessment of excess deaths from all causes because the reported number of deaths due to COVID-19 do not accurately reflect the true death toll. We assessed excess mortality in 2020 and 2021 in the Netherlands. Methods: All analyses were performed on data from comprehensive nationwide registers provided by Statistics Netherlands (Centraal Bureau voor de Statistiek), including demographic characteristics and mortality. All-cause mortality incidence rates were calculated per calendar month and compared against COVID-19 infections and preventive strategies. The all-cause mortality incidence rate ratios (IRRs) with 95% confidence intervals (95% CIs) were estimated per calendar year using Poisson regression (overall and for subgroups). Results: Compared with predicted mortality based on 2019 rates, the overall excess mortality was 8.9% (IRR 1.089, 95% CI 1.081-1.097) in 2020 and 8.5% (IRR 1.085, 95% CI 1.077-1.092) in 2021. Relative excess mortality was higher for men, people with low household income, first-generation immigrants, and individuals living in extremely urbanized areas. In 2020, excess mortality was highest in age groups above 75 years (over 10%.); in 2021, it was clearly present even in the 20-39 years age group (6.6%). Conclusions: Our results quantify excess mortality during the first 2 years of the COVID-19 pandemic in the Netherlands. We show that the extent of excess mortality varies considerably across demographic groups, which may help in identifying target groups for preventive strategies during future health crises.