[1] Univ Hull, Wolfson Palliat Care Res Ctr, Hull York Med Sch, Kingston Upon Hull, N Humberside, England
[2] Univ Sheffield, Sect Publ Hlth, Sch Hlth & Related Res, Sheffield, S Yorkshire, England
[3] Univ Sheffield, Sch Nursing & Midwifery, Sheffield, S Yorkshire, England