Chest
Original Research: COPDDefining the Asthma-COPD Overlap Syndrome in a COPD Cohort
Section snippets
Patients
Patients with COPD participating in the COPD History Assessment in Spain (CHAIN) cohort were included. CHAIN is a multicenter study of 36 Spanish prospective cohorts carried out at university hospitals. Methodology and recruitment strategy have been reported elsewhere.10 Briefly, this is an active ongoing prospective cohort study of patients with COPD being followed since 2010. COPD was defined by smoking history ≥ 10 pack-years and a postbronchodilator FEV1/FVC < 0.7 after 400 μg of inhaled
Patient Characteristics
Eight-hundred thirty-one patients included in the CHAIN cohort were analyzed and 125 patients (15%) met the criteria for ACOS (Fig 1). Demographic and clinical characteristics of these patients as compared with patients with COPD not fulfilling the criteria for ACOS are shown in Table 2. As expected from a population with COPD, patients were predominantly male, with predominantly mild to moderate disease assessed by lung function or BODE and with high prevalence of respiratory symptoms. Out of
Discussion
We have applied prospectively, for the first time, precise diagnostic criteria to identify patients with the asthma and COPD overlap syndrome in a large cohort of well-characterized patients with COPD followed for up to 1 year. We found that, by using usual features of asthma in a well-characterized COPD population but stratified by major and minor criteria, we can identify this particular phenotype in 15% of a hospital-based COPD outpatient cohort, and these criteria were sustained after 1
Conclusions
We propose a set of easily applicable clinical criteria (Table 1) that can be useful to define the ACOS. In a well-characterized cohort of patients with COPD, 15% of patients fulfilled these criteria, sustained them after 1 year, and, although this phenotype was not associated with baseline clinical differences, were associated to different survival.
Acknowledgments
Author contributions: B. G. C. and J. B. S. contributed to the design of the study, made the analysis, and wrote the manuscript; B. G. C. is the guarantor of the manuscript; and J. L. L.-C., M. C.-R., J. J. S.-C., J. P. d.-T., J. M. M., C. M.-G., P. d. L., I. M., G. P.-B., N. F.-C., I. S., I. A., and C. C. contributed to patient recruitment and reviewed the manuscript.
Financial/nonfinancial disclosures: The authors have reported to CHEST the following: B. G. C. has received lecture fees from
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Cited by (0)
FUNDING/SUPPORT: We thank AstraZeneca for their partial financial support to perform this study. The COPD research program of the Spanish Respiratory Society (PII de EPOC of SEPAR) endorsed this study.