September 2019
REG’s Asthma-COPD Overlap (ACO) working group has recently completed a study determining the prevalence and clinical characteristics of asthma-COPD overlap in UK primary care practices. The cross-sectional study, led by Jerry Krishnan and Nicolas Roche and supported by REG and OPC, investigated the prevalence of ACO in individuals ≥40 years old, with ≥2 outpatient primary care visits over a 2-year period that had a diagnosis code for COPD, asthma, or both asthma and COPD in primary care settings.
One in five of patients met the REG ACO working group’s criteria for an ACO diagnosis (a) aged ≥40 years, (b) current or former smoker, (c) post-bronchodilator airflow limitation (FEV1/FVC < 0.7) and (d) ≥12% and ≥200 mL reversibility in post-bronchodilator FEV1. The prevalence of ACO was higher in patients with a diagnosis of both asthma and COPD (32%) compared with a diagnosis of COPD only (20%, p<0.001) or asthma only (14%, p<0.001). Demographic and clinical characteristics of ACO varied across these three source populations.
A limitation in the field of ACO research has been the lack of a widely accepted ACO definition; in this study the REG ACO working group have developed a definition that can be used to test the prevalence of ACO in other populations and in observational and clinical studies to understand the implications of ACO for patients in primary care.
https://www.atsjournals.org/doi/abs/10.1513/AnnalsATS.201809-607OC