Pulmonary Disease, Chronic Obstructive

• Hôpital privé la Louvière — Lille, France

• Beth Israel Deaconess Medical Center — Boston, Massachusetts, United States

• Emad Zarief Kamel Said — Asyut, Egypt

• Hospital of clinics of the federal university of uberlândia — Uberlândia, Minas Gerais, Brazil

• King's College Hospital, Bessemer Road, Denmark Hill — London, United Kingdom

• Aalborg University Hospital — Aalborg, Nothern Jutland, Denmark

• Massachusetts General Hospital — Boston, Massachusetts, United States
• Cleveland Clinic Children's — Cleveland, Ohio, United States
• Texas Children's Hospital — Houston, Texas, United States

• University of Rochester Medical Center — Rochester, New York, United States

Not specified

• Respiratory ICU, Post Graduate Institue of Medical Education and Research — Chandigarh, India