Abstract:
Many preference-based measures can be used to elicit the utility values for economic analyses. The EQ-5D is a commonly and widely used health preference-based measure because it can generate the utitiliy value for the calculation of quality adjusted life years (QALYs) for cost-utility analysis recommended by several health technology assessment guidelines including Thai. The SF-6D developed from the SF-12v2 is another health preference-based measure to generate the utility values for QALYs calculation. Both EQ-5D and SF-6D can be used for a large health population survey in Thailand. Moreover, the Thai World Health Organization Quality of Life-BREF (WHOQOL-BREF) can be employed to generate the utility values through a mapping formula with the EQ-5D among the general Thai population. This study therefore aimed to establish the population norms of the Thai version of those health preference-based measures among the general Thai population. A cross-sectional survey study was conducted using face-to-face interviews with 2,000 general Thai samples. Each sample was required to complete the following: 1) Demographic characteristics, 2) EQ-5D-5L, 3) SF-12v2, 4) WHOQOL-BREF, 5) EQ-5D-3L and 6) EQ-VAS. Descriptive statistics were used to report norm-based scores stratistified by age band and sex categories. Moreover, Generalized Linear Model (GLM) with Poisson family and log link function was employed to investigate the associations between sociodemographic factors and utility values obtained from the health preference-based measures. The mean (percentage of ceiling effects) of EQ-5D-3L, EQ-5D-5L, SF-6D, WHOQOLBREF and EQ-VAS scores were 0.845 (57.80%), 0.923 (49.05%), 0.798 (14.30%), 0.932 (2.35%), and 79.83 (3.20%), respectively. Older participants reported lower EQ-5D-3L, EQ-5D-5L, SF6D, WHOQOL-BREF and EQ-VAS scores than their counterparts. Other demographic factors could affect the utility values obtained from some health preference-based measures including monthly household incomes associated with the utility values obtained from the WHOQOL-BREF. The Thai norm-bases scores are established to benchmark the utility values from those health preference-based instruments. Age is the only significant factor affecting the utility values obtained from those measures. Moreover, it is expected to inform the policy makers to better allocate health care resources to the population group with diminished norm-based scores.