[1] Univ York, Epidemiol & Canc Stat Grp, York YO10 5DD, N Yorkshire, England
[2] York Hosp, Dept Palliat Care, York YO31 8HE, N Yorkshire, England
[3] Univ Hull, Wolfson Palliat Care Res Ctr, Kingston Upon Hull HU6 7RX, N Humberside, England
[4] Castle Hill Hosp, Queens Ctr Oncol & Haematol, Kingston Upon Hull HU16 5JQ, N Humberside, England
[5] York Hosp, Dept Haematol, York YO31 8HE, N Yorkshire, England