Association between blood eosinophil count with asthma hospital readmissions

Abstract

Introduction: The presence of eosinophils in asthma inflammation is a relevant factor in the pathophysiology of the disease, however the relationship between the blood eosinophil count (BEC) with asthma severity and prognosis is still under debate. The aim of this work is to analyze the relationship between the BEC levels and hospital readmissions in patients with asthma.

Material and methods: A review was retrospectively carried out on all admissions of patients over 18 years old due to exacerbation of asthma occurring in our hospital between the years 2000 and 2010. The personal characteristics and the asthma personal history of each patient were recorded. The BEC was determined from the first blood sample taken from the patient after their arrival at the hospital. Hospital early, late and frequent readmissions were analyzed using 4 cut-off points; less than 150 eosinophils/μL vs ≥150/μL, less than 200 vs 200 /μL, less than 300 vs ≥300/μL, and less than 400 vs ≥400/μL.

Results: We have included 1316 patients, 70% of whom are women, as well as a mean age of 60 years, and a mean FEV1 of 73.5% of the reference value. The mean eosinophil blood count was 201.7 cells/μL. A BEC ≥300 cells/μL showed a reduction of risk of late readmission of 42%, a BEC ≥400 cells/μL showed a reduction in late readmission risk of 41% and decrease in frequent late readmission of 63%.

Conclusions: Our study appears to support that an elevated BEC is associated with a lower incidence of asthma hospital readmissions.

Keywords: Asthma; Eosinophils; Hospital admissions; Prognosis; Readmissions; Severity.