Pulmonary Disease, Chronic Obstructive

• Investigational Research Center Site #1017 — Andalusia, Alabama, United States
• Investigational Research Center Site #1003 — Jasper, Alabama, United States
• Investigational Research Center Site #1008 — Glendale, Arizona, United States
• Investigational Research Center Site #1034 — Los Angeles, California, United States

• Medical University of South Carolina — Charleston, South Carolina, United States

• Marmara University — Istanbul, Maltepe, Turkey (Türkiye)

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

• Hospital of South West Jutland — Esbjerg, Denmark
• Lillebaelt Hospital — Vejle, Denmark

• Royal Free Hospital NHS — London, NW3 2PF, United Kingdom

• 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

• 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

Not specified

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