Abstract
Background: Elevated blood eosinophils (eos) may be associated with exacerbations in COPD. We examined this relationship in a managed care organization.
Methods: In this cohort study using administrative pharmacy and health care utilization data, we identified 5,915 patients aged ≥40 years with an encounter diagnosis (Dx) for COPD from 2009–2012, post-bronchodilator FEV1/FVC <0.7 between 2 years prior and 6 months after the encounter Dx, and a blood eos determination not associated with systemic corticosteroids (SC) or infections within 1 year after the Dx. COPD exacerbations were defined as hospitalizations or emergency department visits with a principal Dx of COPD or SC dispensing within ±14 days of an outpatient visit for COPD exacerbation. The relationship of baseline blood eos count as a continuous and a binary variable using different cutoffs to future COPD exacerbation rate was evaluated by Poisson regression with robust error variance, adjusting for demographics, comorbidities, and disease burden, and stratified by baseline blood neutrophil (neu) count.
Results: Greater eos counts at baseline were associated with an increased risk of COPD exacerbations in the follow-up year for patients with low neu counts (<5,000 cells/µL). There was no association for those with high neu.
Conclusions: Elevated blood eos count is an independent risk factor for COPD exacerbations in patients with lower neu. More studies are needed to confirm this relationship.
- Copyright ©the authors 2016
