The Role of the De Ritis Ratio in ICU Mortality Among Critically Ill Patients with COVID-19

AbstractObjective: The De Ritis ratio (aspartate aminotransferase/alanine aminotransferase) has emerged as a prognostic biomarker in critical illness. This study aimed to evaluate the independent prognostic value of the De Ritis ratio for ICU mortality in critically ill patients with COVID-19.Methods: This retrospective observational cohort study was conducted at a single tertiary center. Medical records of 642 adult patients with RT-PCR–confirmed COVID-19 admitted to the Internal Medicine ICU between January and December 2021 were reviewed. Demographic data, comorbidities, laboratory parameters, severity scores (APACHE II and SOFA), and organ support requirements were recorded at ICU admission. Patients were stratified into survivor and non-survivor subgroups. Independent predictors of ICU mortality were identified through two multivariable logistic regression models. Discriminative performance was assessed by receiver operating characteristic curve analysis.Results: ICU mortality was recorded in 341 patients (53.1%). Non-survivors were significantly older and had markedly elevated inflammatory biomarkers, D-dimer, urea, and De Ritis ratio values. Although absolute AST and ALT concentrations did not differ significantly between groups, the De Ritis ratio independently predicted ICU mortality in both models (Model A: OR 1.27, 95% CI 1.06–1.51, p = 0.009; Model B: OR 1.26, 95% CI 1.05–1.50, p = 0.013). Combining the De Ritis ratio with severity scores improved discrimination (AUC up to 0.661).Conclusion: The De Ritis ratio at ICU admission independently predicted mortality in critically ill COVID-19 patients and provided prognostic information beyond established severity scores. Its derivation from routine laboratory data supports its role as a cost-neutral supplementary stratification tool.