Relationship between the urea–creatinine ratio and mortality in septic patients with and without chronic kidney disease: A retrospective single-center Chinese intensive care unit cohort study

Background The urea-creatinine ratio (UCR) has shown potential as an indicator for predicting mortality in sepsis. However, its utility, especially in patients with chronic kidney disease (CKD), remained inadequately explored, particularly in the Chinese population. This study aimed to evaluate the predictive value of UCR for in-hospital mortality in septic patients and to examine its relationship with CKD status. Methods This single-center retrospective Chinese intensive care unit (ICU) cohort study analyzed data from a revised intensive care database. Logistic regression models were used to assess the independent association between UCR and in-hospital mortality. Receiver operating characteristic (ROC) curves were employed to evaluate predictive accuracy, and stratified analyses examined interactions between UCR and clinical factors. Results Among 453 septic patients, 36.2% experienced in-hospital mortality. The UCR was identified as an independent risk factor for mortality (OR 1.054, 95% CI 1.034–1.076; P  < 0.001) and exhibited particularly strong predictive performance in patients without CKD. The predictive accuracy of the UCR alone was comparable to that of the Sequential Organ Failure Assessment (SOFA) score alone (AUC 0.686, 95% CI 0.621–0.751 vs. AUC 0.694, 95% CI 0.629–0.760). The combination of the UCR and the SOFA score demonstrated the highest predictive accuracy for mortality in septic patients without CKD (AUC 0.806, 95% CI 0.753–0.858). Conclusions Higher UCR is an independent predictor of in-hospital mortality in septic patients, particularly in those without CKD. When combined with the SOFA score, UCR may enhance sepsis risk stratification. Further validation studies are needed to confirm these findings.