Impacts of Demographic and Clinical Characteristics on Disease Severity and Mortality in Patients with Confirmed COVID-19

Background: We investigated potential predictive factors for mortality and disease severity from demographic and clinical data, comorbidities, and laboratory findings in patients with confirmed COVID-19 who were consecutively admitted to our tertiary hospital. Methods: In this retrospective, single-center, observational study, we enrolled consecutive 540 adult patients who had COVID-19 confirmed by a molecular method. Patients were categorized into three groups based on disease severity. Patients' demographic and clinical characteristics, mortality rates, and mortality-associated factors were analyzed. Results: The overall mortality rate was 4.3% (23/540). Disease severity was mild in 40.9% (n = 221), severe in 53.7% (n = 290), and critical in 5.4% (n = 29) of the patients. There were significant differences among groups in terms of median white blood cell (WBC), hemoglobin, neutrophil, lymphocyte, and thrombocyte counts, as well as C-reactive protein (CRP), procalcitonin, lactate dehydrogenase (LDH), creatinine, albumin, D-dimer, ferritin, troponin, and fibrinogen levels. Furthermore, there were significant differences between surviving and non-surviving patient groups in terms of median WBC, hemoglobin, neutrophil, and lymphocyte counts, as well as CRP, procalcitonin, LDH, creatinine, albumin, D-dimer, and ferritin levels. CRP level (odds ratio [OR]: 1.020, 95% confidence interval [CI]: 1.009-1.032; p < 0.001), and CURB-65 score (OR: 4.004, 95% CI: 1,288-12,447; p = 0.017) were independently associated with disease severity and mortality. Conclusion: On admission, WBC, neutrophil, lymphocyte, and platelet counts can be used to predict disease severity in patients with COVID-19. CRP, ferritin, LDH, creatinine, troponin, D-dimer, fibrinogen, and albumin levels can also be used to predict disease severity in these patients. Finally, elevated CRP level and high CURB-65 score were predictors of disease severity and mortality.