[1] Imperial Coll Healthcare NHS Trust, Hammersmith Hosp, London W12 0HS, England
[2] Univ Sheffield, Sch Med & Biomed Sci, Sheffield, S Yorkshire, England
[3] Royal Brompton Hosp, London SW3 6LY, England
[4] Univ Nottingham Hosp, NHS Trust, Nottingham, England
[5] Hillingdon Hosp NHS Trust, Uxbridge, Middx, England
[6] Imperial Coll Healthcare NHS Trust, Charing Cross Hosp, London W12 0HS, England
[7] RAF Ctr Aviat Med, Hitchin, Herts, England
[8] Imperial Coll Healthcare NHS Trust, Hammersmith Hosp, Natl Pulm Hypertens Unit, London W12 0HS, England
[9] Western Gen Hosp, Resp Unit, Edinburgh EH4 2XU, Midlothian, Scotland
[10] Pontefract Dist Gen Hosp, Pontefract, Yorks, England
[11] N Hampshire Hosp, Basingstoke, Hants, England
[12] Univ London Imperial Coll Sci Technol & Med, NHLI Charing Cross, London, England
[13] Virgin Atlantic Airways, Surrey, England
[14] Chelsea & Westminster HIV Dept, London, England
[15] Westminster NHS Fdn Trust, London, England
[16] Western Gen Hosp, Resp Funct Serv, Edinburgh EH4 2XU, Midlothian, Scotland
[17] Univ London Imperial Coll Sci Technol & Med, NHLI Hammersmith, London, England
[18] UK Confidential Reporting Programme Aviat & Marit, Farnborough, Hants, England
[19] Univ Aberdeen, Aberdeen, Scotland