Validity, feasibility and acceptability of time trade-off and standard gamble assessments in health valuation studies: A study in a multiethnic Asian population in Singapore

- Wee, Hwee-Lin; Li, Shu Chuen; Xie, Feng; Zhang, Xu-Hao; Luo, Nan; Feeny, David; Cheung, Yin-Bun; Machin, David; Fong, Kok-Yong; Thumboo, Julian