Prognostic value of systemic inflammatory indicators in patients with severe pneumonia

To analyze the correlation between systemic inflammatory indicators and severe pneumonia severity, and evaluate their prognostic value for 28-day mortality.

This retrospective study included 75 severe pneumonia patients treated at The First People's Hospital of Lin'an District from October 2022 to December 2023. Systemic inflammation indices - Systemic Immune-Inflammation Index (SII), Systemic Inflammatory Response Index (SIRI), Neutrophil-to-HDL-C ratio (NHR), Lymphocyte-to-HDL-C ratio (LHR), and Monocyte-to-HDL-C ratio (MHR) - were calculated from routine blood and biochemical tests. Spearman correlation analyzed relationships with APACHE II scores. Prognostic value was assessed using ROC curve analysis. Kaplan-Meier survival analysis was performed based on predefined thresholds, and sensitivity analysis evaluated model robustness.

SII, SIRI, NHR, LHR, and MHR levels were significantly higher in the group that died versus the group that survived (P < 0.001). Spearman analysis showed significant positive correlations of SIRI, NHR, and MHR with APACHE II scores (P < 0.001), with MHR exhibiting the strongest correlation (r = 0.556). Multivariate logistic regression, adjusted for procalcitonin (PCT) and neutrophil count (NEU), identified all five markers as independent factors for 28-day mortality. ROC analysis showed AUC values of 0.719, 0.688, 0.758, 0.810, and 0.802 for SII, SIRI, NHR, LHR, and MHR, respectively, with a combined AUC of 0.896. Survival analysis revealed elevated SII, LHR, and MHR associated with reduced survival (P < 0.001). Sensitivity analysis confirmed marker stability as mortality predictors.

Systemic inflammatory indices (SII, SIRI, NHR, LHR, and MHR) in severe pneumonia patients significantly correlated with poor prognosis, and their combination exhibited excellent predictive value for adverse outcome.