1Director of Research, National Respiratory Training Centre, The Athenaeum, 10 Church Street, Warwick CV34 4AB, UK
2Senior Lecturer (hon.), University of Edinburgh, UK
3Professor of Primary Care Research and Development, Primary Care Research and Development, Division of Community Health Sciences and General Practice, University of Edinburgh, UK
4Research Advisor, National Respiratory Training Centre, The Athenaeum, 10 Church Street, Warwick CV34 4AB, UK
*Tel.: +44 1926 838975; fax: +44 1926 493224. E-mail address: s.walker@nrtc.org.uk.