Population-Based Preference Weights for the EQ-5D Health States Using the Visual Analogue Scale (VAS) in Iran

BACKGROUND Health-related quality of life (HRQoL) is used as a measure to valuate healthcare interventions and guide policy making. The EuroQol EQ-5D is a widely used generic preference-based instrument to measure Health-related quality of life. OBJECTIVES The objective of this study was to develop a value set of the EQ-5D health states for an Iranian population. PATIENTS AND METHODS This study is a cross-sectional study of Iranian populations. Our sample from Iranian populations consists out of 869 participants, who were selected for this study using a stratified probability sampling method. The sample was taken from individuals living in the city of Tehran and was stratified by age and gender from July to November 2013. Respondents valued 13 health states using the visual analogue scale (VAS) of the EQ-5D. Several fixed effects regression models were tested to predict the full set of health states. We selected the final model based on the logical consistency of the estimates, the sign and magnitude of the regression coefficients, goodness of fit, and parsimony. We also compared predicted values with a value set from similar studies in the UK and other countries. RESULTS Our results show that the HRQoL does not vary among socioeconomic groups. Models at the individual level resulted in an additive model with all coefficients being statistically significant, R(2) = 0.55, a value of 0.75 for the best health state (11112), and a value of -0.074 for the worst health state (33333). The value set obtained for the study sample remarkably differs from those elicited in developed countries. CONCLUSIONS This study is the first estimate for the EQ-5D value set based on the VAS in Iran. Given the importance of locally adapted value set the use of this value set can be recommended for future studies in Iran and In the EMRO regions.