Clinical and Laboratory Predictors of COVID-19 Severity and the Need for Intensive Care: A Retrospective Cohort Study

Introduction: To identify demographic, clinical, imaging, and laboratory predictors of disease severity and intensive care unit (ICU) requirement in patients with coronavirus disease 2019 (COVID-19).
Methods: This retrospective cohort study was conducted between March and August 2020 in the Department of Infectious Diseases. The study included suspected or confirmed cases of COVID-19. Patients’ data were retrieved from the hospital’s electronic medical records and patient files.
Results: The study included 500 patients. Increasing age and elevated ferritin levels were independently associated with severe COVID-19. Although not statistically significant, delayed admission showed a trend toward increased disease severity. Patients requiring ICU care had significantly higher C-reactive protein (CRP), lactate dehydrogenase (LDH), ferritin, and aspartate aminotransferase (AST) levels, along with lower absolute lymphocyte counts at admission. The multivariable model demonstrated good calibration (Hosmer-Lemeshow p=0.978) and acceptable discrimination (area under the curve=0.76).
Discussion and Conclusion: Advanced age and elevated ferritin levels were independent predictors of severe COVID-19. Higher CRP, LDH, ferritin, and AST levels, along with lower absolute lymphocyte counts, were associated with ICU requirement. Early assessment of these routinely available laboratory parameters may facilitate timely risk stratification and improve clinical management.

Keywords: COVID-19; Pandemic; Risk factors