Association between clinical pulmonary infection score and mortality in patients with severe pneumonia: a systematic review and meta-analysis.

Background: The association of clinical pulmonary infection score (CPIS) with risk of mortality in patients with severe pneumonia remains unclear now. This study aimed to identify the prognostic role of CPIS for mortality among severe pneumonia patients based on available evidence. Methods: PubMed, Chinese National Knowledge Infrastructure (CNKI), and Web of Science (WOS) databases were searched up to August 30, 2025. Observational studies evaluating the association between CPIS and mortality in patients with severe pneumonia were included. Odds ratios (ORs) with 95% confidence intervals (CIs) were combined and subgroup by age, combination of multiple organ failure (MOF), and type of CPIS variable were performed. Results: Ten observational studies involving 1,048 patients were included with the mortality rate of 34.3% (359/1,048). Pooled results demonstrated that higher CPIS was significantly related to increased risk of mortality in patients with severe pneumonia (OR =3.19, 95% CI: 2.28-4.45, P<0.001). Then subgroup analyses by the age (elderly: OR =5.90, P<0.001; mixed: OR =2.23, P<0.001), combination of MOF (yes: OR =5.90, P<0.001; no: OR =1.89, P=0.002; nor reported: OR =3.60, P=0.023) and type of CPIS variable (categorical: OR =5.90, P<0.001; continuous: OR =2.23, P<0.001) manifested consistent results. Conclusions: CPIS was significantly associated with the risk of mortality in severe pneumonia and patients with higher CPIS were exposed to the increased risk of death.