Lujia Guan,1,* Jiachen Li,2,* Lirong Liang,2 Zhaohui Tong1 

1Department of Respiratory and Critical Care Medicine, Beijing Research Center for Respiratory Infectious Diseases, Beijing Institute of Respiratory Medicine and Beijing Chao Yang Hospital, Capital Medical University, Beijing, People’s Republic of China; 2Evidence-Based Medicine Center, Beijing Institute of Respiratory Medicine and Beijing Chao-Yang Hospital, Capital Medical University, Beijing, People’s Republic of China

*These authors contributed equally to this work

Correspondence: Lirong Liang, Evidence-Based Medicine Center, Beijing Institute of Respiratory Medicine and Beijing Chao-Yang Hospital, Capital Medical University, 8 Gongren Tiyuchang Nanlua, Chaoyang District, Beijing, People’s Republic of China, 100020, Email llrcruie@163.com Zhaohui Tong, Department of Clinical Epidemiology, Beijing Research Center for Respiratory Infectious Diseases, Beijing Institute of Respiratory Medicine and Beijing Chao Yang Hospital, Capital Medical University, 8 Gongren Tiyuchang Nanlua, Chaoyang District, Beijing, 100020, People’s Republic of China, Email tongzhaohuicy@sina.com

Background and Objective: Blood eosinophil (EOS) levels are considered a potential biomarker for acute exacerbation of chronic obstructive pulmonary disease (AECOPD) management, but the impact of EOS stability during hospitalization on outcomes is unclear. This study examined the relationship between EOS stability and clinical outcomes in these patients.
Methods: A retrospective analysis was conducted on 2105 AECOPD patients hospitalized at Beijing Chao-Yang Hospital from 2013 to 2022. Patients were classified into four groups according to EOS counts (2%) at admission and discharge: persistent high, decreased, increased, and persistent low. Clinical characteristics and outcomes were compared between EOS stability groups. Multivariable logistic regression was used to evaluate the association between EOS stability and adverse hospital outcomes. Cox regression analysis was performed to assess the risk of AECOPD-related readmission within three years. Receiver operating characteristic (ROC) curves and nomograms were used to evaluate the predictive performance of the models.
Results: There were 586 (27.8%), 154 (7.3%), 593 (28.2%), and 772 (36.7%) patients in the persistent high, decreased, increased, and persistent low groups, respectively. Multivariable logistic regression analysis showed that the persistent high EOS group had a significantly lower risk of adverse hospital outcomes compared to the persistent low EOS group (aOR: 0.77, 95% CI: 0.59– 0.99, P = 0.040). The nomogram developed based on the multivariate model demonstrated good predictive accuracy for adverse hospital outcomes, with an AUC of 0.67, and was well-calibrated. Cox regression analysis revealed that the persistent high EOS group had a higher risk of AECOPD-related readmission within three years compared to the persistent low EOS group (aHR: 1.38, 95% CI: 1.13– 1.68, P = 0.001).
Conclusion: Blood eosinophil stability during hospitalization is associated with AECOPD prognosis and may help guide inpatient treatment and identify patients at higher risk of future readmission.

Keywords: acute exacerbation of chronic obstructive pulmonary disease, eosinophil, adverse hospital outcome