Effects of systemic corticosteroids on blood eosinophil counts in asthma: real-world data

Abstract

Introduction: Systemic corticosteroids (SCS) are effective anti-inflammatory therapies for patients with severe or persistent asthma. Use of SCS reduces blood eosinophil counts; the magnitude and duration of reduction in real-world settings needs further investigation. Objective: To examine the SCS effect on blood eosinophil counts over time among patients with asthma in a real-world setting. Methods: This retrospective study used Reliant Medical Group (Worcester, MA) electronic medical records between January 2011 and December 2015. Patients aged ≥12 years with ≥1 SCS prescription (first: index date), ≥1 asthma diagnosis, and ≥1 eosinophil count in each 12-month pre- and post-index periods were included for the study. Endpoints included SCS treatment patterns, time to SCS discontinuation, and changes in index blood eosinophil counts (≥150, ≥300, and ≥400 cells/µL) with SCS initiation and discontinuation. Results: At index visit, 642 of 1198 included patients had a blood eosinophil count ≥150 cells/µL. After an average initial SCS prescription of 35 mg/day, mean (% change) eosinophil counts at month 1 in the ≥150, ≥300, and≥400 cells/µL subgroups decreased from index by 112 (−30%), 202 (−34%), and 290 (−36%) cells/µL, respectively. Of the patients with an eosinophil count ≥150 cells/µL at index, who discontinued SCS within 7, 14, or 21 days after the index date, 21%, 26%, and 25% had an eosinophil count <150 cells/µL 1-month post-index, respectively. Conclusion: Blood eosinophil counts decreased following initiation of SCS therapy and had not returned to index levels several weeks after SCS discontinuation. The time frame of SCS discontinuation is an important consideration when identifying patients with eosinophilic asthma.

Keywords:

• Systemic corticosteroids
• eosinophil counts
• severe eosinophilic asthma
• real world

Acknowledgements

The authors wish to thank Devi Sundaresan at RMG for her help with data extraction and interpretation. Editorial support (in the form of writing assistance, including development of the initial draft based on author direction, assembling tables and figures, collating author comments, and grammatical editing and referencing) was provided by Chris Tan, PhD, at Fishawack Indicia Ltd., UK, and was funded by GSK.

Declaration of interest

H. O., J.-P. L., C. B., and B. H. are GSK employees and hold stocks/shares. M.-H. L., M. S. D., G. G., and D. L. are employees of Analysis Group, Inc., a consulting company that has received research funds from GSK. S. S. is an employee of RMG Research Department, which has received research funds from GSK.

Additional information

Funding

This study was funded by GSK [HO-16-16495]. GSK employees contributed to the study design, analysis and interpretation of data, the writing of the manuscript, and the approval of the final version to be submitted. The decision to submit for publication was that of the authors alone. The sponsor did not place any restrictions on access to the data or on the statements made in the manuscript. The authors had full access to all the data in the study and had final responsibility to submit for publication.