[1] Univ Hull, Wolfson Palliat Care Res Ctr, Hull York Med Sch, Kingston Upon Hull, England
[2] Univ Hull, Hull Hlth Trials Unit, Kingston Upon Hull, England
[3] Univ Wollongong, Dept Med & Hlth, Wollongong, NSW, Australia
[4] Univ Hull, Hull York Med Sch, Kingston Upon Hull, England
[5] Newcastle Univ, Populat Hlth Sci Inst, Newcastle Upon Tyne, England