Relative importance of the EQ-5D five dimensions among patients with chronic diseases in South Korea – a comparison with the general population preference weights

BACKGROUND: Who should provide the values of health states in economic evaluations of health technologies has long been the subject of debate. This study examined and compared the relative importance of the EQ-5D five dimensions, using both patient-reported values and general population tariffs, among patients with chronic diseases in South Korea and also assessed the pattern of the discrepancy between patient and general population values by type of chronic diseases. METHODS: Data were taken from the 2013 Korea Health Panel survey. This analysis focused on adult patients with chronic diseases (n = 3216). Patient-reported EQ-5D profiles and visual analogue scale (VAS) values were used to assess the relative importance of the EQ-5D five dimensions among these patients, using a linear regression model. The relative importance of the EQ-5D dimensions was then compared to the EQ-5D tariffs elicited from the general population. The relative magnitude of the discrepancies between patient and general population values was also assessed by type of chronic diseases. RESULTS: Anxiety/depression and pain/discomfort appeared to have the largest impact on the self-rated patient VAS, which fairly contrasted with the general population model. In addition, a further regression analysis showed that the discrepancy between patient and general population values varied with the type of chronic diseases. The greatest discrepancy between the two was found in patients with diseases of the blood and blood-forming organs, neoplasms and diseases of the digestive system. CONCLUSIONS: These analyses revealed differences in the relative weights attached to the EQ-5D dimensions between patient groups and the general population, particularly in those ‘non-tangible’ dimensions. These differences consequently led to greater discrepancies between patient and general population values in certain patient groups, which can have significant implications for resource allocation decisions in South Korea.