Estimating an EQ-5D value set for Malaysia using time trade-off and visual analogue scale methods

Area of Science:

• Health Economics
• Psychometrics
• Societal Valuations

Background:

• The EuroQol 5-Dimension (EQ-5D) questionnaire is a widely used tool for measuring health status.
• Developing country-specific EQ-5D value sets is crucial for accurate health economic evaluations.
• Malaysia lacked a validated EQ-5D value set for cost-utility studies.

Purpose of the Study:

• To estimate a unique EQ-5D value set for Malaysia.
• To employ both Time Trade-Off (TTO) and Visual Analogue Scale (VAS) valuation methods.
• To provide a tool for conducting cost-utility analyses in the Malaysian healthcare context.

Main Methods:

• Face-to-face surveys were conducted with patients, caregivers, and health professionals across nine Malaysian government hospitals (2004-2005).
• Valuations were obtained for 45 distinct EQ-5D health states using TTO and VAS.
• Linear additive regression models (N3 and D1 specifications) were applied for data analysis, with model selection based on statistical significance and goodness of fit.

Main Results:

• 152 respondents provided 2174 TTO and 2265 VAS valuations.
• TTO valuations were perceived as more difficult and exhibited greater inconsistencies compared to VAS.
• The N3 model demonstrated the best fit for VAS data, achieving a mean absolute error of 0.032.

Conclusions:

• A Malaysian EQ-5D value set has been successfully estimated.
• This value set is suitable for use in cost-utility studies in Malaysia.
• The study acknowledges limitations inherent in the survey methodology.