Mapping Utility Scores From the HeartQoL Questionnaire Into the EQ-5D for Ischemic Heart Disease

Abstract

Objective: The HeartQoL is an ischemic heart disease (IHD) core questionnaire. This study aimed to map the HeartQoL to the EQ-5D to provide the specific patients' health status and utility using one instrument.

Methods: We conducted a cross-sectional study investigating IHD patients in China using the Chinese HeartQoL and EQ-5D. Data based on the total group were fitted by 2 linear regression models with the utility score derived from the EQ-5D as a dependent variable and the HeartQoL total and subscale (physical and emotional) scores as independent variables, respectively. The 2 models were compared via modeling fitting statistics.

Results: In total, 406 IHD patients were enrolled in China. The mean HeartQoL global score for the total group was 1.75 (standard deviation [SD] = 0.85), whereas the mean physical and emotional scores were 1.65 (SD = 0.91) and 1.99 (SD = 0.93), respectively. The mean utility calculated by the EQ-5D for IHD patients was 0.66 (SD = 0.38), as compared with 0.95 (SD = 0.06) for healthy people. From the linear regression model with total score, the total score was a significant predictor for the EQ-5D utility, with the equation as EQ-5D = 0.085 - 0.3294 × total. In the linear regression model with physical and mental scores, both scores were significant predictors for the EQ-5D utility, with an equation as EQ-5D = 0.0671- 0.2091 × physical - 0.1248 × mental. The fitting statistics suggest that the model using the HeartQoL total score is preferred.

Conclusion: As the first effort to map the HeartQoL to EQ-5D, the linear relationship between these 2 instruments was explored, and this could potentially be useful in future health technology assessment decision making and clinical practice.

Keywords: EQ-5D; HeartQoL; health-related quality of life; mapping; utility. values.