Lung Diseases, Obstructive

• 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

• Tidarat Somreusean — Bangkok, Thailand

• Chaudary Muhammad Akram Teaching Hospital, Azra Naheed Medical College, Superior University — Lahore, Punjab Province, Pakistan

• San Raffaele Hospital — Milan, Italy

• Papanikolaou General Hospital — Thessaloniki, Greece

Not specified

• Faculty of medicine mansoura university — Al Mansurah, Egypt

• Evangelical University of Goiás — Anápolis, Goiás, Brazil

• Arizona Pain Institute — Scottsdale, Arizona, United States
• University of Arkansas for Medical Sciences (UAMS) — Little Rock, Arkansas, United States
• HCA Healthcare Research Institute / St. Luke's Presbyterian — Denver, Colorado, United States
• Nona Medical Arts — Orlando, Florida, United States

• Marshfield Clinic Research Institute — Marshfield, Wisconsin, United States