1. Department of Respiratory Medicine, Royal Devon and Exeter Hospital, Exeter EX2 5DW, UK
2. School of Psychology, University of Plymouth, Plymouth PL4 8AA, UK
3. The Honiton Group Practice, Honiton EX14 2NY, UK
4. Department of Primary Care, University of Exeter Medical School, Exeter EX1 2LU, UK
5. GSK Respiratory Global Franchise, Exeter UB11 1BT, UK