기관지폐쇄증, 폐암, 간질폐질환, 섬유소흉 등 기저폐질환 환자와 흉곽새장의 기형이 공존하는 환자는 제외됐다.
Patients with underlying lung disease, such as bronchiectasis, lung cancer, interstitial lung disease and fibrothorax, and those with co-existing deformity of the thoracic cage were excluded.