Burden of disease associated with a COPD eosinophilic phenotype

Purpose: Based on blood and sputum samples, up to 40% of patients with COPD have eosinophilic inflammation; however, there is little epidemiology data characterizing the health care burden within this sub-population. Given that COPD-attributable medical costs in the USA are predicted to approach $50 billion by 2020, we analyzed the effect of blood eosinophil counts and exacerbations on health care resource utilization and costs. Patients and methods: This cross-sectional study used electronic medical records and insurance claims data from the Reliant Medical Group (January 2011 December 2015). Eligible patients were >= 40 years of age, continuously enrolled during the year of interest (2012, 2013, 2014, or 2015), had >= 1 COPD-related code in the preceding year, and documented maintenance therapy use. Patients with >= 1 blood eosinophil count recorded were stratified into 2 cohorts: <150 cells/mu L and >= 150 cells/mu L. Endpoints included demographics, clini- cal characteristics, health care resource utilization, and costs. The impact of blood eosinophil count and exacerbation patterns on health care resource utilization and costs was assessed with multivariate analyses. Results: On average, 2,832 eligible patients were enrolled annually, of whom similar to 28% had >= 1 eosinophil count recorded during the year. The >= 150 cells/mu L cohort had numerically higher all-cause and COPD-related health care resource utilization and cost each year compared with the <150 cells/mu L cohort, but varied by service and year. Among patients with exacerbations, the >= 150 cells/mu L cohort exhibited significantly higher COPD-related costs compared with the <150 cells/mu L cohort. Conclusion: Blood eosinophil counts may be a useful biomarker for burden of disease in a subgroup of patients with COPD.