[1] Queen Mary Univ London, London EC1M 6BQ, England
[2] Northwick Pk Hosp & Clin Res Ctr, Acute Med, Harrow HA1 1UJ, Middx, England
[3] Whittington Hlth, Acute Med, London N19 5NF, England
[4] London Sch Econ, London WC2A 2AE, England
[5] Cheltenham Gen Hosp, Haematol, Cheltenham GL53 7AN, Glos, England
[6] Barts Hlth NHS Trust, Acute & Metab Med, London E1 1BB, England