1 University of Exeter College of Medicine, University of Exeter Medical School, Exeter, United Kingdom of Great Britain and Northern Ireland; d.m.g.halpin@ex.ac.uk.
2 University of California, Berkeley, Environmental Health Sciences, School of Public Health, Berkeley, California, United States.
3 University of California, San Francisco, Department of Medicine, San Francisco, California, United States.
4 University of Michigan, Division of Pulmonary and Critical Care Medicine, Ann Arbor, Michigan, United States.
5 University of Ferrara, Research Centre on Asthma and COPD, Ferrara, Italy.
6 Cornell Medical College, New York, New York, United States.
7 Hospital Universitario de Caracas, Servicio de Neumonología , Caracas, Venezuela, Bolivarian Republic of.
8 University of Lagos, Department of Medicine, College of Medicine, Lagos, Nigeria.
9 Pulmocare Research and Education (PURE) Foundation, Clinical Research, Pune, MAHARASHTRA, India.
10 St. Paul's Hospital, University of British Columbia, Medicine, Vancouver, British Columbia, Canada.
11 State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Disease, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China.
12 University of Barcelona Faculty of Medicine and Health Sciences, Barcelona, Spain.
13 University of Marburg, Pulmonary Diseases, Marburg, Germany.