Predictive Value of NLR and Bilirubin Levels in the Readmission of AECOPD

Objective: To analyze acute exacerbation of chronic obstructive pulmonary disease(AECOPD) readmission events and to determine whether neutrophil-to-lymphocyte ratio(NLR) and bilirubin level are associated with readmission after discharge due to AECOPD . Methods: A total of 170 patients with AECOPD were included. Patients were stratified into the readmission group if patients have two or more readmission within 2 years of the previous discharge and non-readmission group with one readmission or none within 2 years of the last discharge. Basic characteristics, laboratory examinations and clinical data of them were collected retrospectively and compared between these two groups. Then the patients were separated by the cutoffs of NLR and bilirubin level. The number of all-cause readmission within 2 years, time to first COPD-related readmission, 1-year and 2-year COPD-related readmission, 1-year and 2-year all-cause mortality were compared between groups respectively . Results: Compared with readmission group, patients of non-readmission group had shorter length of hospital stay(P=0.034), more systemic corticosteroids use(P=0.007), higher NLR(P=0.001), higher bilirubin levels(P=0.010) and lower eosinophils counts(P=0.001). NLR and bilirubin level at admission can significantly influence the number of all-cause readmission(p=0.002, P<0.001, respectively). Lower bilirubin was associated with an increased risk of 1-year COPD-related readmission(OR 5.063, 95%CI 1.091-23.498) and 2-year COPD-related readmission(OR 4.699, 95% CI 1.269-17.396) . Conclusion: For patients with AECOPD, longer hospital stay and less use of systemic corticosteroids may be associated with higher risk of readmission. NLR and bilirubin level at admission may be related to the number of all-cause readmission. Bilirubin can be regarded as a biomarker to predict readmission rates within 2 years after discharged throughout the course of disease.