Association between the global immune-nutrition-inflammation index and ICU mortality in patients with pneumonia

Background Pneumonia is a major cause of morbidity and mortality among critically ill patients, and early identification of high-risk individuals is essential for guiding clinical management. The Global Immune-Nutrition-Inflammation Index (GINI) is a recently developed composite biomarker that integrats inflammatory, immune, and nutritional parameters. This study aimed to evaluate the association between GINI and intensive care unit (ICU) mortality among patients admitted with pneumonia. Methods This retrospective, single-center observational study included adult patients admitted to the ICU with pneumonia between January 2018 and March 2025. Demographic characteristics, clinical scores, laboratory parameters, complications, and outcomes were recorded. GINI was calculated at ICU admission using the formula: (C-reactive protein×platelets×monocytes×neutrophils)/(albumin×lymphocytes). The primary outcome was ICU mortality. Receiver operating characteristic (ROC) analysis was performed to determine the discriminative ability of GINI for ICU mortality, and multivariable logistic regression was used to identify factors independently associated with mortality. Results A total of 170 patients were included, of whom 106 (62.4%) died during ICU stay. Non-survivors had significantly higher GINI values compared with survivors ( p < 0.001). ROC analysis showed that GINI had moderate discrimination for ICU mortality with an area under the curve (AUC) of 0.702 (95% CI: 0.622–0.781; p < 0.001). The optimal cutoff value was ≥ 4908, yielding a sensitivity of 60.4% and specificity of 78.1%. In multivariable analysis, older age (OR 1.036, 95% CI 1.014–1.058), higher SOFA score (OR 1.326, 95% CI 1.108–1.586), GINI ≥4908 (OR 6.024, 95% CI 2.528–14.354), lower hemoglobin (OR 0.769, 95% CI 0.639–0.927), and lower PaO₂/FiO₂ ratio (OR 0.994, 95% CI 0.989–0.998) were independently associated with ICU mortality. Conclusions GINI was independently associated with ICU mortality and demonstrated moderate discriminatory ability among patients with pneumonia. A GINI value ≥ 4908 was associated with higher odds of ICU mortality after adjustment for established clinical variables. Further prospective multicenter studies are needed to confirm this association and determine the prognostic utility of GINI in this population.