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Association Between the Sequential Organ Failure Assessment-2 (SOFA-2) Score and 90-Day and 365-Day Mortality in
Zhengchao Li1,2, Yuzhu Wang3, Yudong Gao4
1.Department of Emergency Medicine, The First People's Hospital of Yunnan Province.
Background:
The Sequential Organ Failure Assessment-2 (SOFA-2) score is a recently developed update of the conventional SOFA score that incorporates contemporary patterns of organ support in the intensive care unit (ICU). However, the association between SOFA-2 and long-term mortality in patients with sepsis has not been well characterized.
Methods:
This retrospective cohort study extracted adult sepsis ICU data from MIMIC-IV v3.1. ICU admission SOFA-2 scores (0-24) were calculated. Boruta algorithm selected confounders; binary logistic regression and restricted cubic splines (RCS) analyzed linear association between SOFA-2 and 90-/365-day all-cause mortality. Random forest (RF) combined key predictors, SHAP interpreted feature importance, and AUC evaluated discriminative performance.
Results:
8,779 patients were enrolled. Fully adjusted regression showed SOFA-2 independently elevated 90-day mortality (OR=1.17, 95%CI 1.15-1.18) and 365-day mortality (OR=1.16, 95%CI 1.14-1.18). RCS confirmed an approximately linear correlation (all nonlinearity p>0.05). Single SOFA-2 yielded modest AUCs: 0.65 (90-day) and 0.64 (365-day). The RF model improved prediction (validation AUC: 0.68 for 90-day, 0.67 for 365-day). SHAP analysis identified SOFA-2 as the most influential predictor.
Conclusions:
SOFA-2 provides moderate, stable long-term mortality discrimination for sepsis patients. Further external validation and optimization are required to improve its risk stratification utility.
Insights
The updated Sequential Organ Failure Assessment-2 (SOFA-2) score moderately predicts long-term mortality in sepsis patients. This score shows stable discrimination for 90-day and 365-day survival in the intensive care unit.
Area of Science:
- Critical Care Medicine
- Clinical Epidemiology
- Biostatistics
Background:
- The Sequential Organ Failure Assessment-2 (SOFA-2) score is an updated measure for intensive care unit (ICU) organ support.
- Its association with long-term sepsis patient mortality remains under-characterized.
Purpose of the Study:
- To evaluate the association between the SOFA-2 score and 90-day and 365-day all-cause mortality in adult ICU sepsis patients.
- To assess the predictive performance of SOFA-2 for long-term mortality.
Main Methods:
- Retrospective cohort study using MIMIC-IV v3.1 adult sepsis ICU data.
- SOFA-2 scores calculated at ICU admission; confounders selected using Boruta algorithm.
- Logistic regression and restricted cubic splines analyzed SOFA-2 association with mortality; Random Forest and SHAP values assessed predictive performance.
Main Results:
- SOFA-2 independently predicted elevated 90-day (OR=1.17) and 365-day (OR=1.16) mortality.
- An approximately linear correlation was observed between SOFA-2 and mortality.
- Random Forest models improved prediction (AUCs 0.68-0.67), with SOFA-2 identified as the key predictor by SHAP analysis.
Conclusions:
- SOFA-2 demonstrates moderate and stable discrimination for long-term mortality in sepsis patients.
- Further external validation and optimization are necessary to enhance its risk stratification utility.