Xiaoling Huang,1,* Lihua Huang,2,* Shicai Zhao,1 Lingyan Yuan,3 Xing Wang,4 Guanghua Tang,4 Kaifen Yuan,5 Min Xiao4 

1Department of Respiratory, Sichuan Provincial People’s Hospital East Sichuan Hospital & Dazhou First People’s Hospital, Dazhou, Sichuan, People’s Republic of China; 2Department of Infection Disease, The First Affiliated Hospital of Dali University, Dali, Yunnan, People’s Republic of China; 3Department of Endocrinology, First People’s Hospital of LuLiang County, Qujing, Yunnan, People’s Republic of China; 4Department of Laboratory Medicine, Sichuan Provincial People’s Hospital East Sichuan Hospital & Dazhou First People’s Hospital, Dazhou, Sichuan, People’s Republic of China; 5Department of General Medicine, The Second Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, People’s Republic of China

*These authors contributed equally to this work

Correspondence: Kaifen Yuan, Department of General Medicine, The Second Affiliated Hospital of Kunming Medical University, No. 374, Dianmian Avenue, Wuhua District, Kunming, Yunnan, 650000, People’s Republic of China, Email 2548733853@qq.com Min Xiao, Department of Laboratory Medicine Sichuan Provincial People’s Hospital East Sichuan Hospital & Dazhou First People’s Hospital, 522 Xiwai Tashi Road, Tongchuan District, Dazhou, Sichuan, 635000, People’s Republic of China, Email xiaominkv@163.com

Objective: To investigate the prognostic value of hematological indices derived from routine blood tests in assessing 30-day mortality risk among elderly patients with bacterial pneumonia at the time of admission.
Methods: This study was conducted in the Second Affiliated Hospital of Kunming Medical University. A total of 292 elderly patients with bacterial pneumonia were enrolled. A total of 292 elderly patients diagnosed with bacterial pneumonia were classified into two groups: the survival group (n= 256) and the mortality group (n=36). Following a Propensity Score Matching at a 1:1 ratio, differences in clinical data between the two groups were analyzed using the chi-square test and Mann–Whitney U-test. Furthermore, Spearman correlation analysis was employed to explore the relationships among the variables. The Receiver Operating Characteristic (ROC) curve was used to evaluate the predictive value of each index for 30-day mortality in elderly patients with bacterial pneumonia. Subsequently, pivotal risk indices were identified through multivariate logistic regression and Kaplan-Meier survival curves were constructed to illustrate the survival outcomes.
Results: NLR, SII, SIRI and NMLR in the death group were significantly higher than those in the survival group (14.64 vs 5.47, 2621.05 vs 1308.01, 5.58 vs 2.36, 15.05 vs 5.75) (all P< 0.05). And it was positively correlated with IL-6, PCT and hsCRP (all P< 0.05). The ROC curve showed that the AUC of NLR, SII, SIRI and NMLR were 0.777,0.705,0.673 and 0.775 respectively. Multivariate Logistic regression analysis showed that NLR and PCT were the main risk indicators. When NLR≥ 15.46 (OR 18.44), SII≥ 2295.02 (OR 6.25), SIRI≥ 2.49 (OR 4.38) and NMLR≥ 15.72 (OR 17.00), the 30-day mortality of elderly patients with bacterial pneumonia was significantly increased.
Conclusion: In elderly patients with community-acquired bacterial pneumonia, increased NLR, SII, SIRI and NMLR can predict 30-day mortality to a certain extent, but further multicenter studies are needed to verify.

Keywords: elderly patients, community-acquired pneumonia, 30-day mortality, NLR, SII, SIRI, NMLR