Early Risk Stratification for Sepsis: A Combined Model of SOFA Score, PNI and NAR — A Retrospective Study

Objective Sepsis prognosis is shaped by organ dysfunction, inflammation, and nutritional status. We evaluated the individual and combined prognostic value of the Sequential Organ Failure Assessment (SOFA) score, prognostic nutritional index (PNI), and neutrophil-to-albumin ratio (NAR) in predicting 28-day poor outcomes in sepsis patients. Methods This retrospective study included 120 patients with sepsis. Multivariable logistic regression identified independent predictors of 28-day poor outcomes. Receiver operating characteristic curve analysis evaluated the predictive performance of SOFA, PNI, NAR, and C-reactive protein/albumin ratio (CAR) with area under the curve (AUC) calculations. A combined model was constructed using independent predictors, and Kaplan-Meier curves with log-rank tests compared 28-day poor prognosis-free survival rates. Results SOFA score (OR = 1.76 per point, 95%CI:1.16–2.67, P = 0.008), PNI (OR = 0.43 per unit, 95%CI:0.26–0.71, P = 0.001), and NAR (OR = 53.94 per unit, 95%CI:1.46–1993.54, P = 0.030) were independent predictors; CAR was not. AUC values were 0.850 (SOFA), 0.955 (PNI), 0.833 (NAR), and 0.780 (CAR). The combined model (SOFA + PNI+NAR) yielded an AUC of 0.973, significantly higher than each individual indicator (P < 0.05). Patients with a high SOFA score (≥ 3.5), high NAR (≥ 0.474), or low PNI (< 27.68) had significantly lower 28-day poor prognosis-free survival rates (P < 0.001). Conclusions SOFA score, PNI, and NAR independently predict 28-day poor outcomes in sepsis patients. Their combination provides superior prognostic accuracy, offering a practical tool for clinical early risk stratification.