1. The Ottawa Hospital, Ottawa Hospital Research Institute and the University of Ottawa; Department of Medicine; 501 Smyth Road Ottawa ON Canada K1H 8L6
2. The Ottawa Hospital, General Campus; Division of Respirology; 501 Smyth Road Box 211 Ottawa ON Canada K1H 8L6
3. University Medical Center Utrecht; Julius Center for Health Sciences and Primary Care; PO Box 85500 Utrecht Netherlands 3508 GA
4. University of Göttingen Medical School; Department of General Practice/Family Medicine; Ludwigstrasse 37 Freiburg Germany D-79104
5. Maastricht University Medical Center; Department of Respiratory Medicine; PO box 5800 Maastricht Netherlands 6202 AZ
6. CAPNETZ STIFTUNG; Hannover Germany
7. University of Ottawa; Department of Family Medicine, Bruyere Research Institute; 43 Bruyere St Room 369Y Ottawa ON Canada K1N 5C8