Clinical significance of controlling nutritional status score in predicting ICU admission, prolonged hospitalization, and in-hospital mortality in emergency sepsis: a single-center retrospective study

Abstract

Sepsis is associated with high mortality in critically ill patients. Existing prognostic tools are often complex or require specialized testing. This study aimed to evaluate the prognostic value of the Controlling Nutritional Status (CONUT) score in patients with sepsis in the emergency department. A retrospective analysis of 1,200 sepsis patients admitted to the emergency department of the Affiliated Changsha Central Hospital, Hengyang Medical School, University of South China from January 2020 to June 2025 was conducted. Kaplan–Meier analysis, multivariable Cox regression, restricted cubic splines (RCS), receiver operating characteristic (ROC) curves, and decision curve analysis (DCA) were employed to evaluate the associations between the CONUT score and ICU admission, prolonged hospitalization, and in-hospital all-cause mortality. Subgroup and sensitivity analyses were performed. Time-dependent Cox regression revealed that each one-point increase in the CONUT score was associated with an 11% increase in the risk of in-hospital mortality (HR = 1.11, 95% CI:1.02–1.21). After adjusting for potential confounders, logistic regression analysis further demonstrated that, the CONUT score was significantly associated with ICU admission (OR = 1.16, 95% CI: 1.09–1.23) and prolonged hospitalization (OR = 1.11, 95% CI: 1.05–1.17). RCS revealed linear positive correlations. ROC analysis showed that CONUT was superior to SOFA for predicting prolonged hospitalization, and combining CONUT with SOFA enhanced predictive performance. DCA indicated the combined model provided the highest clinical net benefit. Advanced age, diabetes, and mechanical ventilation modified the associations between CONUT and certain outcomes. Elevated CONUT scores are independently associated with adverse outcomes in emergency department sepsis patients, serving as a simple prognostic indicator for early risk stratification.