[1] Tan Tock Seng Hosp, Dept Palliat Med, Singapore 308433, Singapore
[2] HCA Hosp Care, Singapore, Singapore
[3] Natl Canc Ctr Singapore, Dept Palliat Med, Singapore, Singapore
[4] Assisi Hosp, Singapore, Singapore
[5] Natl Univ Canc Inst, Singapore, Singapore
[6] Dover Pk Hosp, Singapore, Singapore