Socioeconomic inequality of health-related quality of life in cancer survivors in South Korea

Background We investigated the inequalities in health-related quality of life (HRQoL) among cancer survivors in Korea, focusing on income and education levels. The slope index of inequality (SII) and relative index of inequality (RII) were utilized to analyze these disparities. Methods Data from the Korea National Health and Nutrition Examination Survey (KNHANES) conducted between 2007 and 2021 was analyzed. The HRQoL was assessed using the EQ-5D questionnaire, which included five problem areas: mobility, self-care, usual activity, pain/discomfort, and anxiety/depression. Logistic regression was employed to calculate the odds ratios (ORs) for each education and income level, indicating the probability of reporting problems. Furthermore, the slope index of inequality (SII) and relative index of inequality (RII) were calculated to evaluate the inequalities in HRQoL. Results Among the 3396 cancer survivors, a considerable proportion reported pain/discomfort (29.6%) and mobility problems (21.1%). The logistic regression results demonstrated a higher likelihood of experiencing problems in all five EQ-5D items among individuals with lower income or education levels. Specifically, compared to the high-income group, the adjusted ORs for mobility problems were 2.19, 1.64, and 1.08 for the low, low-medium, and medium-high-income groups, respectively (p-value < 0.05). Notably, significant income inequalities in HRQoL problems were observed, with the greatest disparities seen in self-care and usual activity problems, as indicated by the SII and RII values. Conclusion Socioeconomic disparities in HRQoL exist among cancer survivors in Korea, particularly related to income levels. Addressing the financial burdens of cancer treatment for individuals with low-income levels may help improve their HRQoL and mitigate these inequalities.