Pulmonary Disease, Chronic Obstructive

• National center for cardiology and internal medicine — Bishkek, Kyrgyzstan
• Eastern Switzerland University of Applied Sciences — Sankt Gallen, Canton of St. Gallen, Switzerland

• National center for cardiology and internal medicine — Bishkek, Kyrgyzstan

• Istanbul Medeniyet University Faculty of Medicine — Istanbul, Turkey (Türkiye)

• Royal Prince Alfred Hospital — Sydney, New South Wales, Australia
• Mount Druitt Hospital — Sydney, New South Wales, Australia
• Prince of Wales Hospital — Sydney, New South Wales, Australia
• Westmead Hospital — Sydney, New South Wales, Australia

• Severance Hospital, Yonsei University Health System — Seoul, South Korea

• Peking University First Hospital — Beijing, Beijing Municipality, China
• The Second Affiliated Hospital of Chongqing Medical University — Chongqing, Chongqing Municipality, China
• Xinqiao Hospital, Army Medical University — Chongqing, Chongqing Municipality, China
• First Affiliated Hospital of Guangzhou Medical University — Guangzhou, Guangdong, China

• San Raffaele Hospital — Milan, Italy

• Papanikolaou General Hospital — Thessaloniki, Greece

Not specified

• Faculty of medicine mansoura university — Al Mansurah, Egypt