Table 1.

Criteria for Diagnosis of Asthma–Chronic Obstructive Pulmonary Disease Overlap Syndrome

Major

1. Persistent airflow limitation [post-bronchodilator FEV1/FVC <0.70 or LLN] in individuals 40 years of age or older; LLN is preferred. 2. At least 10 pack-years of tobacco smoking OR equivalent indoor or outdoor air pollution exposure [eg biomass] 3. Documented history of asthma before 40 years of age OR BDR of >400 mL in FEV1

Minor

1. Documented history of atopy or allergic rhinitis 2. BDR of FEV1 ≥200 mL and 12% from baseline values on 2 or more visits 3. Peripheral blood eosinophil count of ≥ 300 cells/μL

Notes: The committee recommends the presence of all three major criteria and at least one minor criterion for asthma-chronic obstructive pulmonary disease overlap syndrome. FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; BDR, bronchodilator response using 400 mg of albuterol/salbutamol [or equivalent]; LLN, Lower limit of normal. Reproduced with permission of the © ERS 2021: European Respiratory Journal 48 (3) 664–673; DOI: 10.1183/13993003.00436-2016 Published 31 August 2016. Reproduced from: Sin DD, Miravitlles M, Mannino DM, et al. What is asthma-COPD overlap syndrome (ACOS)? Towards a consensus definition from a roundtable discussion. Eur Respir J. 2016;48: 664–673.¹⁵ Copyright © ERS 2016.