Role of peripheral eosinophilia in acute exacerbation of chronic obstructive pulmonary disease

Table 3 Cox regression analysis of time to first chronic obstructive pulmonary disease-related readmission

Variables	Hazard ratio (adjusted)	95%CI: Lower–upper limit	P value
Group (EOS vs non-EOS)	1.488	1.195-1.854	< 0.001
FEV1 % predicted value	0.985	0.979-0.991	< 0.001
Age	1.010	1.000-1.020	0.049
BMI	0.985	0.961-1.009	0.208
Gender (male vs female)	0.951	0.692-1.305	0.754

Cox regression analysis was used to clarify the risk factors associated with time to first chronic obstructive pulmonary disease-related readmission. COPD: Chronic obstructive pulmonary disease; EOS: Patients with eosinophil count ≥ 2%; Non-EOS: Patients with eosinophil count < 2%; FEV1: Forced expiratory volume in one second; BMI: Body mass index; CI: Confidence interval.