1Department of Public Health and Primary Care, Leiden University Medical Center, the Netherlands
2Department of Public Health and Caring Sciences, Family Medicine and Clinical Epidemiology, Uppsala University, Sweden
3Spanish Primary Care Respiratory Group (GRAP), Spain.
4Department of Public Health and General Practice, Norwegian University of Science and Technology, Norway
5School of Population Health & Clinical Practice, University of Adelaide, Australia
6University of Alberta, Canada
7International Primary Care Respiratory Group (IPCRG), United Kingdom
8Peninsula Medical School, University of Plymouth, United Kingdom
9Department of General Practice, University Medical Center Groningen, the Netherlands
10Centre of Academic Primary Care, University of Aberdeen, United Kingdom
*Department of Public Health and Primary Care, Leiden University Medical Center, Hippocratespad 21, Zone V0-P, PO Box 9600, 2300 RC Leiden, The Netherlands. Tel: +31 (0)71 526 8444 Fax: +31 (0)71 526 8259 E-mail: n.h.chavannes@lumc.nl