Lung Diseases, Obstructive

• Guangzhou institute of respiratory disease — Guangzhou, Guangdong, China

• St. Joseph's Health Care — London, Ontario, Canada

• VA Greater Los Angeles Healthcare System, West Los Angeles, CA — West Los Angeles, California, United States
• VA Eastern Colorado Health Care System, Denver, CO — Denver, Colorado, United States
• Atlanta VA Medical and Rehab Center, Decatur, GA — Decatur, Georgia, United States
• VA Boston Healthcare System Jamaica Plain Campus, Jamaica Plain, MA — Boston, Massachusetts, United States

• Riley Hospital for Children — Indianapolis, Indiana, United States

• Aintree University Hospital NHS Foundation Trust — Liverpool, United Kingdom
• St Georges University Hospitals NHS Foundation Trust — London, United Kingdom
• Royal Brompton and Harefield Hospital NHS Foundation Trust — London, United Kingdom
• St Mary's Hospital — London, United Kingdom

• DHQ hospital — Daska Kalan, Punjab Province, Pakistan

Not specified

• University of Kansas Medical Center — Kansas City, Kansas, United States

• Columbia University — New York, United States
• Rhode Island Hospital — Providence, Rhode Island, United States

• North Tyneside General Hospital — Newcastle upon Tyne, Northumberland, United Kingdom