Bronchitis, Chronic

• Brigham and Women's Hospital — Boston, Massachusetts, United States

• University of Pittsburgh Emphysema/COPD Research Center — Pittsburgh, Pennsylvania, United States

• Rush University Medical Center — Chicago, Illinois, United States

• Anhui Chest Hospital — Hefei, Anui, China
• Affiliated Beijing Chaoyang Hospital of Capital Medical University — Beijing, Beijing Municipality, China
• Hospital Emergency General — Beijing, Beijing Municipality, China
• The First People's Hospital of Changzhou — Changzhou, Jiangsu, China

• Science 37 — Los Angeles, California, United States
• Stamford Hospital — Stamford, Connecticut, United States
• Hillcrest Medical Research — DeLand, Florida, United States
• Universal Axon Clinical Research — Doral, Florida, United States

• Insituto Nacional de Enfermedades Respiratorias "Ismael Cosío Villegas" — Mexico City, Tlalpan, Mexico

• COPD Foundation — Washington D.C., District of Columbia, United States

• Luigi Sacco University Hospital, Division of Department of Biomedical and Clinical Sciences, University of Milan — Milan, Italy

Not specified

Not specified