Prognostic Value of SIRI in Sepsis: A Retrospective Study and Machine Learning-Based Model Development
Yilin Zhu1, Zhiyang Wang2, Shifeng Li3
1Department of Critical Care Medicine, Zhangjiagang Hospital Affiliated to Soochow University/The First People's Hospital of Zhangjiagang City, Zhangjiagang, 215600, People's Republic of China.
Journal of Inflammation Research
|October 7, 2025
Summary
The Systemic Inflammation Response Index (SIRI) effectively predicts 28-day mortality in sepsis patients. A new prognostic model incorporating SIRI demonstrates high accuracy for sepsis outcomes.
Area of Science:
- Critical Care Medicine
- Sepsis Pathophysiology
- Prognostic Biomarkers
Background:
- Sepsis poses a significant global health challenge with high mortality rates.
- Accurate prognostic tools are crucial for timely clinical decision-making in sepsis management.
- The Systemic Inflammation Response Index (SIRI) has emerged as a promising biomarker for evaluating sepsis prognosis.
Purpose of the Study:
- To investigate the predictive value of SIRI for 28-day outcomes in sepsis patients.
- To develop and validate a prognostic model for predicting 28-day mortality in sepsis.
- To compare the predictive performance of SIRI against established scoring systems like APACHE II and SOFA.
Main Methods:
- Retrospective analysis of adult sepsis patients from two medical centers.
- Utilized restricted cubic splines and ROC curve analysis to assess SIRI's predictive capability.
- Employed Cox regression, Kaplan-Meier curves, Boruta algorithm, LASSO, and logistic regression to build and validate a prognostic model.
- External validation was performed using data from a separate hospital.
Main Results:
- SIRI demonstrated a nonlinear increasing trend with mortality risk and superior predictive capability compared to APACHE II and SOFA scores.
- Higher SIRI levels were significantly associated with poorer 28-day prognosis (p<0.001).
- The developed prognostic model, incorporating SIRI and other factors (BUN, age, P, Lac, MV), showed high predictive performance (AUCs: 0.851-0.908) across training and validation sets.
Conclusions:
- SIRI is a valuable and independent predictor of 28-day prognosis in sepsis patients.
- The developed prognostic model incorporating SIRI offers high accuracy and clinical utility for predicting sepsis mortality.
- This model can aid clinicians in risk stratification and management of sepsis patients.

