Background: There is literature to suggest there is a subtype of COPD patients in which eosinophils may play an important role. Data suggests that this subset of patient are more prone to develop exacerbations, but also have a higher likelihood of responding to inhaled corticosteroid therapy. The objective of this study is to determine if there are different outcomes in patients with COPD and peripheral eosinophilia when they are hospitalized.
Methods: In this observational cohort study, charts from all patients 40 years of age or older admitted with a COPD exacerbation either in Jacobi or North Central Bronx Hospital during 1/1/2016-12/31/16 were reviewed. Information was also collected from chart review for the year following index hospitalization. The following information was gathered: age, gender, blood eosinophil count on index admission, length of stay, time to first COPD exacerbation readmission and number of readmissions for COPD exacerbation. Patients were grouped based on eosinophil count. The cutoff for eosinophils in this study was 200 cell/uL as this value has shown to predict sputum eosinophilia. Comparisons between both groups were made by unpaired t test.
Results: A total of 1155 charts were reviewed. Of them, 340 patients met the criteria of inclusion. The others had either absence of history of COPD in medical records, died within the year of index hospitalization, had corticosteroid treatment within the past 48 hours of index hospitalization or had admissions unrelated to COPD. 240 patients were in the non-eosinophilic group and 100 were in the eosinophilic group. The mean length of stay in the non-eosinophilic group was 7.65 vs 5.74 in the eosinophilic group, with a mean difference of -1.91 days favoring the eosinophilic group (CI of -3.64 to -0.17) and a p value of 0.03. 85 of the 240 non-eosinophilic patients and 45 of the 100 eosinophilic patients had at least one readmission. The mean number of readmissions were 0.79 vs 0.92 in the non-eosinophilic and eosinophilic group respectively, with a mean difference of 0.13 (CI of -0.25 to 0.51) and a p value of 0.49. From those who were readmitted, the mean number of days to first COPD readmission were 107.23 vs 103.62 in the non-eosinophilic and eosinophilic group respectively, with a mean difference of -3.61 (CI of -37.70 to 30.47) and a p value of 0.83.
Conclusions: This study showed that patients with COPD and eosinophilia had a shorter hospital stay during treatment for exacerbation likely due to better response to corticosteroid therapy. A larger sample size is needed to evaluate a difference in time to first COPD readmission and number of readmissions.