Abstract
OBJECTIVE: The aim of this study is to investigate the relationship between risk scores and immune-inflammatory indices with prognosis and mortality in community-acquired pneumonia. Additionally, we aim to examine the association between mortality and the Acute Phase Reactant Index, which we developed using C-reactive protein, procalcitonin, and albumin levels. METHODS: This retrospective study was conducted with 417 patients diagnosed with community-acquired pneumonia who presented to the emergency department of a tertiary care hospital between 2022 and 2023. The patients' demographic data, imaging findings, blood parameters, site of care, and 30-day mortality status were recorded. Risk scores, immune-inflammatory indices, and the Acute Phase Reactant Index were calculated. The risk scores and indices were compared with treatment outcomes and 30-day mortality results. RESULTS: In the receiver operating characteristic analysis, Acute Phase Reactant Index was found to be as effective as other risk scores in predicting mortality. Among them, Acute Phase Reactant Index had the highest area under the curve value. Additionally, in patients transferred from the ward to the ıntensive care unit, when the Acute Phase Reactant Index score cut-off value was set at 1.32, it accurately predicted mortality in 9 out of 13 patients (69.2%). CONCLUSION: It was determined that Acute Phase Reactant Index is a better predictor of mortality than all other scores and inflammatory indices in community-acquired pneumonia. This suggests that the Acute Phase Reactant Index may be used as a prognostic factor in high-mortality lung diseases such as cancer.