Heterogeneity of asthma and COPD overlap

Min-Hye Kim,1 Chin Kook Rhee,2 Kyungjoo Kim,2 Sang Hyun Kim,3 Jung Yeon Lee,4 Yee Hyung Kim,5 Kwang Ha Yoo,6 Young-Joo Cho,1 Ki-Suck Jung,7 Jin Hwa Lee1 1Department of Internal Medicine, College of Medicine, Ewha Womans University, 2Department of Internal Medicine, Seoul St Mary’s Hospital, The Catholic University of Korea, Seoul, 3Big Data Division, Health Insurance Review and Assessment Service, Wonju, 4Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Konkuk University Chungju Hospital, Chungju, 5Department of Pulmonary and Critical Care Medicine, Kyung Hee University Hospital at Gangdong, Kyung Hee University School of Medicine, 6Department of Internal Medicine, Konkuk University College of Medicine, Seoul, 7Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Hallym University Medical Center, Hallym University College of Medicine, Anyang, Republic of Korea Background: Asthma and COPD are heterogeneous diseases. Patients with both disease features (asthma–COPD overlap [ACO]) are common. However, clinical characteristics and socio-economic burden of ACO are still controversial. The aim of this study was to identify the heterogeneity of ACO and to find out the subtypes with clinical impact among ACO subtypes. Methods: In the Korean National Health and Nutrition Examination Survey (KNHANES) conducted between 2007 and 2012, subjects who were ≥40 years and had prebronchodilator FEV1/FVC