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

• Published in: Value in health Vol. 11; no. s1; pp. S3 - S10
• Main Authors: Wee, Hwee-Lin, PhD, Li, Shu-Chuen, PhD, Xie, Feng, PhD, Zhang, Xu-Hao, MSc, Luo, Nan, PhD, Feeny, David, PhD, Cheung, Yin-Bun, PhD, Machin, David, PhD, Fong, Kok-Yong, FRCP (Edin), Thumboo, Julian, FRCP (Edin)
• Format: Journal Article
• Language: English
• Published: Malden, USA Elsevier Inc 01.03.2008; Blackwell Publishing Inc
• Subjects: Acceptability; Adult; Aged; Aged, 80 and over; Asia; Asian Continental Ancestry Group - psychology; Asian Continental Ancestry Group - statistics & numerical data; attitude to death; China - ethnology; comparative study; Cultural Diversity; Feasibility; Feasibility Studies; Female; Health; Health Status; Humans; India - ethnology; Internal Medicine; Interviews as Topic; Malaysia - ethnology; Male; Middle Aged; Multiracial groups; Preferences; Psychometrics; Quality of Life; Singapore; social values; Statistics, Nonparametric; Surveys and Questionnaires; Valuation; value of life; Malaysia; Singapore; China; India; social values; comparative study; attitude to death; value of life; quality of life; Asia
• ISSN: 1098-3015; 1524-4733
• DOI: 10.1111/j.1524-4733.2008.00361.x

Abstract Objectives To assess the validity, feasibility and acceptability of standard gamble (SG) and time trade-off (TTO) assessments in a multiethnic Asian population. Methods Through in-depth interviews performed among Chinese, Malay, and Indian Singaporeans (education ≥ 6 years), we assessed validity of SG/TTO methods for eliciting health preferences by hypothesizing that 1) SG/TTO scores for three hypothetical health states (HS) would exhibit ranked order (decreasing scores with worse HS); and 2) more subjects would rate the most severe HS as worse than dead. Subjects also evaluated feasibility and acceptability of SG/TTO using a 10-point visual analog scale (VAS) and open-ended questions. Ratings were compared using Kruskal–Wallis, Wilcoxon signed-rank tests or tests of proportions. Results Validity: In 62 subjects (90% response rate), as hypothesized, SG and TTO scores exhibited ranked order with increasing HS severity (SG: 0.85, 0.08, −19.00; TTO: 0.85, 0.00, −0.18). More subjects rated the most severe HS as worse than dead (SG: 8%, 39%, 59%; TTO: 8%, 45% and 62%). Feasibility Subjects felt SG and TTO were easy to understand (median VAS scores: 8.0 vs. 8.0, P = 0.87) and to complete (8.0 vs. 8.0, P = 0.84). Acceptability: SG and TTO were well accepted, with TTO less so than SG (median [interquartile range] offensiveness: 2.0 [0, 4.0] vs. 2.0 [0, 3.0], P = 0.045). Overall, subjects did not have a clear preference for SG/TTO (50% vs. 45%, P = 0.70). Conclusions This study suggests the validity, feasibility and acceptability of SG and TTO for population-based HS valuation studies in a multiethnic Asian population.