Estimating EuroQol EQ-5D Scores from Population Healthy Days Data

Abstract

Background. Preference-based assessments of population health, which may be used for cost-utility analyses, are lacking for most states and communities. With adequate population data, preference-based values can be estimated from non-preference-based health-related quality of life (HRQOL) data. This study estimates scores on the EuroQol EQ-5D, a preference-based measure, from the Healthy Days Measures. Methods. No data set from the US population asks both the Healthy Days and EQ-5D questions for the same respondents. Therefore, estimates for EQ-5D scores were obtained indirectly by matching cumulative distributions of the 2 measures. These distributions were estimated from the 2000— 2002 Behavioral Risk Factor Surveillance System (BRFSS) and the Medical Expenditure Panel Survey (MEPS). The validity of estimates was examined by comparing the mean estimated and observed scores across particular population subgroups. A simulation study was conducted to compare the performance of the proposed method to the regression method. Results. The overall mean observed EQ-5D index was 0.871 and the mean estimated EQ-5D index was 0.872. In the majority of examined subgroups, the mean scores demonstrated a good match according to sociodemographic variables and health-related conditions and, with the exception of the most impaired health states, the differences tended to be less than 0.04. Conclusions. This study provided preliminary estimates of EQ-5D scores from the Healthy Days Measures and demonstrated acceptable validity of the estimates. Because the Healthy Days Measures have been included in many state and local surveys, preliminary cost-utility analyses and determination of burden of disease might be able to be conducted at the national, state, and community levels as well as over time. Key words: health-related quality of life; EQ-5D; Healthy Days Measures; cost-effective analysis. (Med Decis Mak ing 2008;28:491— 499)