Optimizing Inhaled Corticosteroid Prescribing in COPD: Evaluating the Impact of Eosinophil Testing on Clinical Outcomes

Purpose Inhaled corticosteroids (ICS) are recommended for select patients with chronic obstructive pulmonary disease (COPD) based on exacerbation history and blood eosinophil counts. Prior studies suggest that ICS are frequently prescribed outside of guideline-based criteria, and eosinophil testing is inconsistently performed in clinical practice. This study evaluated adherence to Global Initiative for Chronic Obstructive Lung Disease (GOLD) eosinophil criteria for ICS prescribing and associated clinical outcomes. Methods This retrospective observational cohort study included adults with COPD receiving care within Cleveland Clinic outpatient practices in Ohio who were newly initiated on an ICS-containing regimen between January 1, 2021, and July 31, 2023. Patients were classified based on whether ICS prescribing aligned with GOLD eosinophil criteria. Outcomes included adherence to GOLD eosinophil recommendations for ICS use, pneumonia incidence, ICS de-escalation, and predictors of prescribing outside guideline-based criteria. Results A total of 688 patients were included. Most patients received ICS outside of GOLD eosinophil criteria (589/688, 86%). Baseline eosinophil testing was performed in 102 patients (15%). Pneumonia incidence was similar among patients prescribed ICS outside versus within guideline-based criteria (15% vs. 16%, p = 0.686). ICS de-escalation was uncommon overall (7%) and occurred at similar rates between groups. A history of prior exacerbations was associated with prescribing within guideline-based indications. Conclusion ICS prescribing frequently occurred outside of GOLD eosinophil criteria, with limited utilization of eosinophil testing in clinical practice. Clinical outcomes were similar regardless of guideline alignment, and ICS de-escalation was infrequent. These findings highlight opportunities to improve integration of eosinophil-guided decision-making into COPD management.