First Wave of COVID-19 Hospital Admissions in Denmark: A Nationwide Population-Based Cohort Study

Jon Gitz Holler*, Robert Eriksson, Thomas Østergaard Jensen, Maarten van Wijhe, Thea Kølsen Fischer, Ole Schmeltz Søgaard, Simone Bastrup Istaelsen, Rajesh Mohey, Thilde Fabricius, Frederik Jøhnk, Lothar Wiese, Stine Johnsen, Christian Søborg, Henrik Nielsen, Ole Kirk, Brigitte Lindegaard Madsen, Zitta Barrella Harboe

*Corresponding author

Research output: Contribution to journalJournal articleResearchpeer-review


Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its associated disease coronavirus disease 2019 (COVID-19), is a worldwide emergency. Demographic, clinical and laboratory factors associated with mortality in Danish patients hospitalised with COVID-19 is limited. Methods: National health registries were used to identify all hospitalized patients with a COVID-19 diagnosis. We obtained demographics, Charlson Comorbidity Index (CCI), and laboratory results on admission and explored prognostic factors for death using multivariate Cox proportional hazard regression and competing risk survival analysis. Results: Among 2,431 hospitalised patients with COVID-19 between February 27th and July 8th (median age 69 years [IQR 53–80], 54.1% males), 359 (14.8%) needed admission to an intensive care unit (ICU) and 455 (18.7%) died within 30 days of follow-up. The seven-day cumulative incidence of ICU admission was lower for females (7.9%) than for males (16.7%), (p < 0.001). Age, high CCI, elevated C-reactive protein (CRP), ferritin, D-dimer, lactate dehydrogenase (LDH), urea, creatinine, lymphopenia, neutrophilia, and thrombocytopenia within 24-hours of admission were independently associated with death within the first week in the multivariate analysis. Conditional upon surviving the first week, male sex, age, high CCI, elevated CRP, LDH, creatinine, urea and neutrophil count were associated with death within 30 days. Males presented with more pronounced laboratory abnormalities on admission. Conclusions: Advanced age, male sex, comorbidity, higher levels of systemic inflammation and cell-turnover were prognostic factors for mortality. Age was the strongest predictor for death, moderate to high level of comorbidity were associated with a nearly two-fold increase in mortality. Mortality was significantly higher for males after surviving the first week.
Original languageEnglish
Article number39
JournalBMC Infectious Diseases
Issue number21
Publication statusPublished - 9 Jan 2021

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