S2888 Systemic Inflammation Response Index (SIRI) as an Independent Predictor of In-Hospital Mortality in Critically Ill Cirrhotic Patients: A MIMIC-IV Based Study

Introduction: The incidence of liver cirrhosis (LC) remains high throughout the world, posing a serious threat to human health, with repeated inflammation, repair and fibrosis being the pivotal factors in the entire pathophysiologic process. Systemic inflammatory response index (SIRI) is the novel indicator for poor prognosis of liver cirrhosis. The aim of this study was to evaluate its prognostic value and the correlation between SIRI and mortality in critically ill liver cirrhosis patients. Methods: This retrospective study analyzed critically ill cirrhotic patients admitted to the ICU (2008–2019) using the MIMIC-IV database. Patient demographics, comorbid conditions, laboratory results, and mortality data were extracted. The systemic inflammation response index (calculated as = neutrophils × monocytes/lymphocytes) was calculated in Excel and categorized as high (≥4.35) or low (≤4.35). Patients with missing baseline labs were excluded. Statistical analysis was performed using SPSS v26. Descriptive statistics (mean and SD, frequency and percentages), chi-square tests, and multivariate regression (adjusted for confounders) assessed associations and mortality risk. ROC curves evaluated predictive value, and Kaplan–Meier analysis (log-rank test) compared survival. A P-value < 0.05 was considered statistically significant. Results: Of 2,344 critically ill cirrhotic patients (61.2% man, mean age 58.7 ± 12.9 years), 28.5% (668) died in-hospital. Non-survivors were older (61.2 ± 11.7 vs 57.7 ± 13.3, P < 0.001) and had more comorbidities (renal disease, severe liver disease, heart failure). Mortality group had higher SIRI (6.8 [5.3–9.2] vs 4.2 [3.1–6.2], P < 0.001), SOFA, and APSIII scores, and lower albumin and calcium. Multivariable logistic regression confirmed SIRI as an independent mortality predictor (OR 1.007, 95% CI: P = 0.027) alongside lower SpO₂, temperature, albumin, higher SOFA, and older age (AUC = 0.799). ROC analysis showed SIRI’s modest predictive ability (AUC = 0.61, cutoff 4.35, 69.3% sensitivity, 53.3% specificity). Kaplan-Meier analysis confirmed worse survival for SIRI ≥4.35 (log-rank P < 0.001). Conclusion: High SIRI (≥4.35) was significantly associated with raised in-hospital mortality in the critically ill cirrhotic patients and independently predicted mortality with moderate discriminatory ability. Moreover, Kaplan–Meier analysis demonstrated poorer survival in the high SIRI group.