Systemic inflammation response index: A good predictor of 30-day all-cause mortality in patients with acute exacerbation of chronic obstructive pulmonary disease.

This study aims to explore the association between the systemic inflammation response index (SIRI) and the prognosis of patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) by retrospectively analyzing clinical data derived from the Medical Information Mart for Intensive Care-III (MIMIC-III) database. A total of 426 AECOPD patients were enrolled in this study, among whom 113 died during the 30-day follow-up period, resulting in a mortality rate of 26.6%. Compared with the survival group, patients in the deceased group had higher levels of SIRI (4.19 [2.19-7.68) versus 6.25 (3.09-15.57) ×109/L, P<.001]. X-tile software was utilized to determine the optimal SIRI cutoff value of 10.56 × 10-9/L for predicting 30-day all-cause mortality. Patients were stratified into 2 groups based on this cutoff value: a low SIRI group (<10.56 × 109/L) and a high SIRI group (≥10.56 × 109/L). Baseline characteristic comparisons demonstrated that patients in the high-SIRI group presented significantly higher 30-day, 90-day, 1-year, and in-hospital mortality than those in the low-SIRI group (all P < .05). After adjustment for potential confounders, the Cox proportional-hazards regression model identified elevated SIRI as an independent risk factor for 30-day all-cause mortality (HR = 1.743, 95%CI: 1.169-2.598, P = .006), and subgroup analyses confirmed the robustness of this correlation. Additionally, ROC curves showed that the area under the curve (AUC) for SIRI was greater than that for white blood cells and neutrophils (AUC 0.612 vs 0.584; 0.612 vs 0.557), but slightly smaller than that for sequential organ failure assessment (AUC 0.612 vs 0.619). Collectively, our findings indicate that SIRI represents a promising novel inflammatory biomarker for predicting 30-day all-cause mortality among patients with AECOPD.