This study aimed to examine health inequalities experienced by individuals with mental disabilities by focusing on health-related quality of life (HRQoL). Specifically, it investigated whether mental disability status affects HRQoL and whether mental ...
This study aimed to examine health inequalities experienced by individuals with mental disabilities by focusing on health-related quality of life (HRQoL). Specifically, it investigated whether mental disability status affects HRQoL and whether mental disability status moderates the relationship between socioeconomic factors and HRQoL. Previous research on the health of individuals with mental disabilities has largely focused on clinical outcomes, such as symptom reduction, thereby paying limited attention to HRQoL and the role of socioeconomic determinants. Moreover, empirical evidence comparing how socioeconomic factors influence HRQoL differently between individuals with and without mental disabilities remains scarce, particularly from a health inequality perspective.
To address this gap, this study integrated two nationally representative datasets—the Survey on the Community Living Conditions of individuals with Mental Disabilities and the Korea National Health and Nutrition Examination Survey. Propensity score matching (PSM) was applied to construct comparable groups of individuals with and without mental disabilities based on sex, age, region of residence, educational attainment, employment status, equivalized household income, and single-person household status. Following the matching process, 170 individuals with mental disabilities were matched one-to-one with 170 individuals without mental disabilities. HRQoL was measured using the EuroQol-5 Dimension (EQ-5D). Given the bounded nature of EQ-5D scores (0-1), their skewed distribution, and ceiling effects, beta regression analysis was employed. The analytical framework was grounded in the revised HRQoL model proposed by Ferrans et al. (2005), integrated with the social determinants of health framework proposed by Dahlgren & Whitehead (1991).
The results showed that individuals with mental disabilities had significantly lower HRQoL scores than those without mental disabilities (0.853 vs. 0.955, p < 0.001). Multivariable beta regression analysis revealed that mental disability status was significantly associated with lower HRQoL (OR = 0.495, 95% CI = 0.400-0.613), even after controlling for socioeconomic factors, indicating a strong and independent association between mental disability status and reduced HRQoL.
A significant moderating effect was observed only for the interaction between mental disability status and educational attainment (OR = 1.555, 95% CI = 1.017-2.377). While educational attainment alone was not significantly associated with HRQoL, its effect emerged among individuals with mental disabilities, suggesting that education plays a differential role in shaping HRQoL within this population.
Subjective health status was also a strong predictor of HRQoL. Compared to those who rated their health as “poor,” individuals who reported “fair” (OR = 2.449, 95% CI = 1.914-3.132) or “good” health (OR = 3.155, 95% CI = 2.374-4.193) demonstrated significantly higher HRQoL. In contrast, other variables—including sex, age, region of residence, inpatient service use, educational attainment, employment status, equivalized income, and single-person household status—were not significantly associated with HRQoL once mental disability status and subjective health were accounted for. This suggests that the influence of mental disability may account for the variance previously attributed to socioeconomic factors.
In conclusion, individuals with mental disabilities experience significantly lower HRQoL compared to those without mental disabilities, and mental disability moderates the relationship between educational attainment and HRQoL. These findings highlight the need for tailored interventions that address the specific characteristics and vulnerabilities of individuals with mental disabilities. In particular, strategies aimed at enhancing educational opportunities may contribute to reducing health inequalities and improving HRQoL among this population.
Keywords: Mental Disabilities, Health Inequalities, Health-Related Quality of Life, Propensity Score Matching, Educational Attainment