Association between biomarkers and COVID-19 severity and mortality: a nationwide Danish cohort study
Gethin Hodges, Jannik Langtved Pallisgaard, Anne‐Marie Schjerning Olsen, Patricia McGettigan, Mikkel Porsborg Andersen, Maria Lukács Krogager, Kristian Kragholm, Lars Køber, Gunnar Gislason, Christian Torp‐Pedersen, Casper N. Bang
Abstract
OBJECTIVE: To evaluate the association between common biomarkers, death and intensive care unit (ICU) admission in patients with COVID-19. DESIGN: Retrospective cohort study. From electronic national registry data, we used Cox analysis and bootstrapping to evaluate associations between baseline levels of biomarkers and standardised absolute risks of death/ICU admission, adjusted for age and gender. SETTING: All hospitals in Denmark. PARTICIPANTS: 1310 patients aged ≥18 years admitted to hospital with COVID-19 from 27th of February to 1st of May 2020, with available biochemistry data. MAIN OUTCOME MEASURES: A composite of death/ICU admission occurring within 30 days. RESULTS: Of the 1310 patients admitted to hospital (54.6% men; median age 73.6 years), 352 (26.9%) experienced the composite endpoint and 263 (20.1%) died. For the composite endpoint, the absolute risks for moderately and severely elevated C reactive protein (CRP) were significantly higher, 21.5% and 39.2%, respectively, compared with 5.0% for those with normal CRP. Moderately and severely elevated leucocytes were significantly higher, 34.5% and 46.6% risk, respectively, compared with 23.2% for those with normal leucocytes. Moderately and severely decreased estimated glomerular filtration rates (eGFR) were significantly higher, 41.5% and 45.9% risk, respectively, compared with 30.4% for those with normal/mildly decreased eGFR. Normal and elevated ureas were significantly higher, 22.3% and 40.6% risk, respectively, compared with 7.3% for those with low urea. Elevated D-dimer was significantly higher, 31.8% risk, compared with 17.5% for those with normal D-dimer. Moderately and severely elevated troponins were significantly higher, 27.7% and 57.3% risk, respectively, compared with 9.4% for those with normal troponin. Elevated procalcitonin was significantly higher, 52.1% risk, compared with 28.0% for those with normal procalcitonin. CONCLUSION: In this nationwide study of patients admitted with COVID-19, elevated levels of CRP, leucocytes, procalcitonin, urea, troponins and D-dimer, and low levels of eGFR were associated with higher standardised absolute risk of death/ICU admission within 30 days.