A decomposition of income-related inequality in EQ-5D: A South Korea study

Abstract

The present study estimated income-related inequality in EQ-5D health-related quality of life (HRQL) scores by applying the concentration index (CI), one of the most popular methods for measuring income-related inequality in health. The main purpose of the study is to decompose the CI measure for an overall EQ-5D index score in order to measure the relative contribution of each of the six dimensions of EQ-5D to overall inequality. We estimated the overall CI at 0.035, indicating that HRQL is concentrated among higher income groups. The CI's for six dimensions varied, ranging from 0.0106 for dysfunction to 0.0014 for mobility, suggesting that the six dimensions did not contribute equally to the overall inequality. Dysfunction and pain/discomfort contributed the most, 30.3% and 29.8% respectively, to the total inequality, compared with small contributions of mobility (3.9%) or self-care (4.4%). These results should be incorporated into the policy deliberation process to reduce income-related inequality in HRQL among South Koreans. © 2012 Inderscience Enterprises Ltd.