[1] Queens Univ Belfast, Sch Nursing & Midwifery, Belfast, Antrim, North Ireland
[2] Queens Univ Belfast, Sch Med Dent & Biomed Sci, Ctr Publ Hlth, Belfast, Antrim, North Ireland
[3] St Vincents Hosp Melbourne, Ctr Palliat Care, Fitzroy, Vic, Australia
[4] Univ Melbourne, Fac Med Dent & Hlth Sci, Melbourne, Vic, Australia
[5] Univ Lancaster, Div Hlth Res, Lancaster, England
[6] Univ Ulster, Sch Nursing, Belfast, Antrim, North Ireland