[1] Kings Coll London, Cicely Saunders Inst, Dept Palliat Care, Royal Marsden NHS Fdn Trust, London WC2R 2LS, England
[2] Kings Coll London, Cicely Saunders Inst, Dept Palliat Care, Royal Brompton NHS Fdn Trust, London WC2R 2LS, England
[3] Univ London Imperial Coll Sci Technol & Med, Dept Palliat Care, Royal Marsden NHS Fdn Trust, London, England
[4] Univ London Imperial Coll Sci Technol & Med, Dept Palliat Care, Royal Brompton NHS Fdn Trust, London, England
[5] Univ London Imperial Coll Sci Technol & Med, Natl Heart & Lung Inst, London, England
[6] Univ London St Bartholomews Hosp Med Coll, Dept Resp Med, London, England
[7] Univ London Imperial Coll Sci Technol & Med, Royal Brompton Hosp, Interstitial Lung Dis Unit, London, England