Disability and health literacy in Korea: evidence from a national survey

Abstract

Health literacy is important for effective disease prevention and health promotion. People with disabilities may require especially strong health literacy because they have higher unmet healthcare needs and more chronic disease. Although some studies suggest lower health literacy among people with disabilities, evidence from nationally representative data is limited. Using the 2021 Korea Health Panel Survey, we assessed health literacy among adults aged 19+ (N = 11,057) and compared those with and without disabilities defined by the National Disability Registration System. Sensitivity analyses used an alternative definition of disability derived from self-reported difficulties in daily activities. Linear regressions adjusted for gender, age, education, income, and chronic conditions. Adults with disabilities scored 0.94 points lower on the 16-point European Health Literacy Survey Questionnaire scale than those without (p < 0.001). Under the alternative definition, the gap was larger at 1.49 points (p < 0.001). Differences varied by disability type: cognitive limitations were associated with the largest deficit (− 3.93, p < 0.001), followed by hearing limitations (− 2.01, p < 0.001); physical disabilities did not differ significantly. These findings indicate clear disparities in health literacy by disability status and heterogeneity across disability types in Korea. Programs and policies to improve health literacy among people with disabilities should be tailored to disability type.

Supplementary Information

The online version contains supplementary material available at 10.1038/s41598-026-51076-y.

Introduction

Health literacy is a critical factor without which disease prevention and health promotion efforts have only limited effects¹. It is particularly important for people with disabilities, who tend to have higher baseline healthcare utilization^2,3 and a higher prevalence of certain chronic conditions^4,5, which require ongoing self-management and frequent interactions with healthcare systems, activities that depend heavily on adequate health literacy.

While disabilities are not universally associated with lower health literacy⁶, some groups appear vulnerable. Deaf or hard-of-hearing individuals are more likely to have inadequate health literacy^7–9, which posed heightened challenges during the COVID-19 pandemic¹⁰. Individuals with intellectual disabilities often struggle to understand their medication¹¹. Americans with disabilities are more likely to admit that obtaining information takes a lot of effort and is frustrating¹².

The conceptual model of health literacy developed by Sørensen et al.¹³ is useful for understanding these disparities. It defines health literacy as a set of competencies involved in accessing, understanding, appraising, and applying health information across healthcare, disease prevention, and health promotion. From this perspective, disability may constrain different stages of information processing in different ways. For example, hearing impairment may hinder access to information and communication with providers, whereas cognitive impairment may primarily affect understanding and appraisal. Thus, the framework helps explain why and how differences may vary across disability groups and motivates disability-type-specific hypotheses about where barriers arise and why disparities may be larger for some groups than others. The framework also suggests that disability-related barriers may compound with disadvantages in education, resources, and social support, creating heightened vulnerability for some groups.

Much of the existing literature is based on convenience study samples, which limits our ability to quantify disparities in health literacy according to disability type or between countries. A notable exception is the study by Nguyen and Gilbert¹², which utilized the nationally representative Health Information National Trends Survey (HINTS) of the United States. However, disability status in the HINTS was inferred from functional difficulties and social interactions rather than self-identification, making it difficult to distinguish disability types. Consequently, the type of disability, i.e., physical or mental, could not be distinguished. In addition, since the HINTS is administered via mail¹⁴, participation rate among people with disabilities may not be comparable to that of those without disabilities.

To address these limitations, we used the Korea Health Panel Survey (KHPS), a nationally representative dataset, to compare health literacy among Korean adults with and without disabilities. The KHPS utilizes a health literacy measure developed in accordance with the conceptual framework of Sørensen et al.¹⁵, which allows theory-based interpretation of the results. Importantly, the KHPS allows comparisons across disability types and includes detailed information on chronic conditions. Chronic conditions are negatively associated with health literacy^16,17, suggesting that better health literacy may help to prevent some of these conditions. However, a dynamic relationship may also exist: the onset of a chronic condition may prompt individuals to seek more information and familiarize themselves with healthcare systems, thereby improving their health literacy¹⁶. While people with disabilities are more likely to have chronic conditions than those without, disabilities and chronic conditions do not always co-occur. This study examined whether the association between chronic conditions and health literacy differs by disability status.

Methods

Data sources

We used data from the 2021 wave of the KHPS, which includes a supplemental section with 16 health literacy questions administered to respondents aged 19 years and older. The KHPS is jointly conducted by the National Health Insurance Service of Korea and the Korea Institute for Health and Social Affairs. It is designed to yield a nationally representative sample through household-based data collection. Trained interviewers conduct in-person interviews with all household members, minimizing potential participation bias according to disability status. The survey also collects detailed sociodemographic information and a wide range of healthcare-related variables, including the presence of chronic medical conditions¹⁸.

Measures

The KHPS measures health literacy using the Korean translation of the short-form version of the European Health Literacy Survey Questionnaire (HLS-EU-Q16)¹⁹. This 16-item instrument is an abridged version of the original 47-item questionnaire developed by a European research consortium²⁰. It asks respondents to rate, on a four-point Likert scale, the level of difficulty they experience when accessing, understanding, evaluating, and applying information related to healthcare, disease prevention, and health promotion. The short form is widely validated and commonly used in studies^20,21. The Korean version was also used in several empirical studies conducted in Korea^22,23. Following the study by Levin-Zamir et al.²¹, the responses “very easy” and “easy” were coded as 1, while the responses “difficult” and “very difficult” were coded as 0. The KHPS includes a fifth response option, “I don’t know,” which was also coded as 0 when calculating the composite health literacy score.

Two definitions of disability were used. The first is based on government registration. In South Korea, a medical diagnosis establishes disability status and eligibility for a registration system offering legal benefits. The KHPS includes this variable, allowing both disability status and type to be identified. However, this definition is not fully aligned with international frameworks, which emphasize the extent to which individuals face challenges in interacting with their environment. To address this, an alternative definition was constructed based on self-reported difficulties in performing daily functions to examine whether the results differ according to the definition of disability used.

The disability registration criteria for the Korean National Disability Registration System²⁴ set by the Ministry of Health and Welfare of Korea define 15 types of disabilities in medical terms, which are often stricter and narrower than the definition of disability by the World Health Organization^24,25. Consequently, approximately 5.1% of the total population of South Korea qualifies for registration. In this study, the 15 types of disabilities were grouped into five broad categories. Categorization was based on how disabilities may affect healthcare needs and literacy. For example, impairments of different internal organs (liver, heart, kidney, etc.) do not necessarily lead to differences in health literacy levels. By contrast, limitations in vision versus hearing have vastly different implications for how a person accesses and processes information. The resulting categories of disabilities included impairments in external body functions and internal organs, and limitations in vision, hearing, and cognitive functions due to intellectual disabilities, autism spectrum disorders, psychiatric disorders, or brain lesions.

An alternative definition of disability was constructed using responses to health-related quality-of-life questions in the KHPS. The KHPS uses the Korean translation of EQ-5D, a widely used instrument that assess five dimensions of daily functions— mobility, ability to bathe and dress oneself, ability to conduct usual activities such as work, school, and leisure activities, level of pain/discomfort, and presence of anxiety or depression²⁶. Individuals were defined as having a disability if they reported difficulties with any of the first three dimensions. This definition aligns with the World Health Organization’s conceptualization of disability, which emphasizes limitations of functioning within social and physical environments, thereby capturing both the medical and social aspects of disability. This definition is also consistent with prior studies that operationalize disability as limitations in basic activities due to physical, mental, or emotional problems^27,28, or serious difficulties with tasks such as walking, bathing, dressing, remembering, and making decisions¹². Other research used one²⁹ or two³⁰ EQ-5D items to identify individuals with disabilities. We selected the first three items because they collectively reflect limitations across physical, cognitive, and social dimensions of functioning, which are areas most relevant to independent daily living and commonly used to define disability in population-level studies.

Sociodemographic characteristics including gender, age, education level, and household income were controlled for. In addition, the presence of a chronic medical condition(s), recorded as a binary variable, was included in the analyses. Participants were invited to report any chronic conditions, with the KHPS providing a suggested list, which includes major cardiometabolic, respiratory, musculoskeletal, hepatic, renal, endocrine, and neuropsychiatric disorders.

Analytical approach and model specifications

We estimated linear regression models of the composite health literacy score as a function of disability measures and covariates using Stata version 18.0 Standard Edition. We estimated five pre-specified models. Model 1 regressed health literacy on an indicator for government-registered disability and sociodemographic covariates. Model 2 replaced the single disability indicator with disability-type indicators. Model 3 added an indicator for the presence of any chronic medical condition. Model 4 added an interaction between registered disability and chronic condition status to assess whether the association between disability and health literacy differs by chronic condition status. Model 5 replicated the baseline specification using the alternative disability definition based on EQ-5D functional limitations (mobility, self-care, usual activities) in place of registration status. We report heteroskedasticity-robust standard errors clustered at the highest-level administrative division (metropolitan cities/provinces) to account for within-region correlation in outcomes and unobserved common shocks. Given the multiple disability-type coefficients in Model 2, we additionally report false-discovery-rate adjusted q-values in the Supplementary Table S4. Because the chronic-condition indicator was missing in some cases, sensitivity analyses were conducted using full information maximum likelihood (FIML) for Model 3 and Model 4 where specifications included this covariate to ensure estimations based only on complete-cases were not biased. Similarly, Model 5, which used the EQ-5D functional-limitation definition of disability, was estimated on the subset of respondents with non-missing EQ-5D responses for the relevant dimensions.

The Kyung Hee University Institutional Review Board [KHUIRB-24-191] approved this study.

Results

Participation and sample characteristics

Out of the 11,413 adults in the survey who were invited to participate in the auxiliary health literacy questionnaire, 880 had registered disabilities. The most common category was impairments in external body functions (see Supplementary Table S1 for the exact list of government-recognized disability types and how they were grouped in this paper).Overall, 356 (3.12%) adults declined to participate (Supplementary Table S2). Specifically, out of the 880 adults with registered disabilities, 87 (9.89%) declined to participate. Compared with the 10,533 adults without any government-registered disabilities, of whom only 269 (2.55%) declined to participate, the participation rate was lower among adults with disabilities. Among the 11,057 adults included in the study, people with disabilities tended to be older than those without, which aligns with the fact that a significant number of people acquire disabilities as they age (Table 1). This participation gap is substantively important because it suggests that observed health literacy among adults with disabilities may be biased upward if non-participation is correlated with difficulty engaging with written health information.

Table 1.

Descriptive statistics of the study sample.

	No registered disability	One or more registered disabilities	p-value
	N = 10,264	N = 793
Sociodemographic factors
Gender
Male	4552 (44.35%)	436 (54.98%)	< 0.001
Female	5712 (55.65%)	357 (45.02%)
Age in years
19–39	1862 (18.14%)	23 (2.90%)	< 0.001
40–59	3268 (31.84%)	130 (16.39%)
60–69	2402 (23.40%)	190 (23.96%)
70+	2732 (26.62%)	450 (56.75%)
Education
Less than high school	3492 (34.02%)	526 (66.33%)	< 0.001
High school diploma or equivalent	3507 (33.44%)	190 (23.96%)
College degree or more	3265 (30.23%)	77 (9.71%)
Household monthly income	4.10	2.24	< 0.001
(unit: 1 million Korean Wons)	[3.77]	[1.95]
Health and related information
Type of disabilities
External body functions impaired	N/A	462 (58.26%)
Internal organ functions impaired	N/A	59 (7.44%)
Vision impaired	N/A	67 (8.45%)
Hearing impaired	N/A	122 (15.38%)
Cognitive limitations	N/A	83 (10.47%)
Any chronic medical condition
Yes	5025 (52%)	638 (84%)	< 0.001
None	4668 (48%)	118 (16%)
Walking
Some or severe difficulties	1342 (14%)	392 (52%)	< 0.001
No difficulties	8242 (86%)	355 (48%)
Bathing/dressing
Some or severe difficulties	355 (4%)	175 (77%)	< 0.001
No difficulties	9229 (96%)	572 (23%)
Daily life (work, school, leisure, etc.)
Some or severe difficulties	892 (9%)	308 (41%)	< 0.001
No difficulties	8692 (91%)	439 (59%)
Pain/discomfort
Some or severe	3043 (32%)	480 (36%)	< 0.001
None	6541 (68%)	267 (64%)
Depression/anxiety
Some or severe	1101 (11%)	169 (23%)	< 0.001
None	8483 (89%)	578 (77%)
Health literacy (maximum score: 16)	11.23	8.14	< 0.001
	[4.62]	[4.79]

Numbers in brackets are standard deviations of continuous variables. Health literacy was measured with HLS-EU-Q16. The reported p-values were calculated using the t- or Chi-square test.

Unadjusted health literacy differences by disability status and type

People with disabilities also tended to have lower education levels than those without, which was partly attributed to them belonging to older generations. People with disabilities generally had lower household incomes and were more likely to have at least one chronic condition. There were some missing values for the indicator of whether participants had any chronic medical condition. However, the pattern of missingness was not significantly associated with government-registered disability status (p = 0.28). Therefore, full information maximum likelihood estimations were conducted on specifications that included the chronic condition indicator, which revealed the original estimation results were not biased (Supplemental Table 3).

Health literacy clearly differed between people with and without disabilities. Out of a maximum of 16 points, the average health literacy scores of people with and without registered disabilities differed by more than 3 points (8.14 and 11.23, respectively) (Table 1). Such a large gap relative to the 16-point scale motivated further decomposition. Individuals with internal organ impairments had the highest average score (10.15 points), following those without any registered disabilities. By contrast, individuals with limited cognitive functions and limited hearing had the lowest average scores (6.65 and 6.45 points, respectively). Such differences across disability types are consistent with the idea that barriers may differ across stages of the health information processing, which we further elaborate in the Discussion.

Adjusted associations between disability and health literacy

When sociodemographic factors were controlled for, the health literacy scores of individuals with disabilities were 0.94 points lower than those of their peers without disabilities (Table 2, Model 1). The reduction from the unadjusted difference indicates that part of the raw disparity is associated with sociodemographic composition, but a residual gap remains. The health literacy scores of individuals with impairments of external and internal body functions did not significantly differ from those of individuals without disabilities. However, individuals with limited cognitive function had significantly lower health literacy scores (3.93 points lower), followed by individuals with limited hearing (2.01 points lower). People with limited vision tended to have lower health literacy scores (Table 2, Model 2). The concentration of the adjusted disparity among cognitive and sensory impairments highlights that differences are not uniform across disability groups. Benjamini-Hochberg false-discovery-rate adjustment was applied across the five disability-type comparisons since Model 2 reports multiple disability-type coefficients but the hearing and cognitive coefficients stayed statistically significant (Supplemental Table S4).

Table 2.

Linear regression estimates of differences in health literacy score (0–16) by disability and chronic condition status on the health literacy score.

	Model 1	Model 2	Model 3	Model 4	Model 5
	Disability status	Disability types	Chronic condition added	Interaction added	Alt. def. of disability
Has a disability	-0.938***		-0.819***	-1.712**	-1.499***
	(0.142)		(0.149)	(0.477)	(0.100)
Type of disability (reference: none)
External body functions impaired		-0.261
		(0.227)
Internal organ functions impaired		0.059
		(0.516)
Vision impaired		-0.790
		(0.534)
Hearing impaired		-2.005***
		(0.330)
Cognitive limitations		-3.925***
		(0.462)
Gender (reference: male)
Female	-0.497***	-0.512***	-0.489***	-0.494***	-0.397***
	(0.071)	(0.069)	(0.080)	(0.081)	(0.076)
Age group (reference: 19–39 years)
40–59 years	-0.423*	-0.434*	-0.251	-0.237	-0.321*
	(0.169)	(0.168)	(0.156)	(0.156)	(0.164)
60–69 years	-1.360***	-1.398***	-0.997***	-0.984***	-1.169***
	(0.210)	(0.210)	(0.181)	(0.179)	(0.217)
70 years or older	-3.856***	-3.892***	-3.377***	-3.365***	-3.351***
	(0.284)	(0.289)	(0.266)	(0.265)	(0.288)
Education (reference: less than high school)
High school diploma or equivalent		2.527***	2.430***	2.432***	2.330***
		(0.148)	(0.151)	(0.152)	(0.149)
High school and more		3.156***	3.008***	2.999***	2.944***
		(0.184)	(0.174)	(0.173)	(0.177)
Monthly household income (in 1 million KRW)		0.074*	0.112***	0.111***	0.106***
		(0.030)	(0.021)	(0.021)	(0.022)
Has a chronic medical condition			-0.517***	-0.567***
			(0.116)	(0.114)
Disability X chronic condition				1.072*
				(0.453)
R-squared (unadjusted)	0.36	0.37	0.36	0.36	0.37
N	11,057	11,057	10,449	10,449	10,331

Coefficients are unstandardized and represent absolute point differences in health literacy score on a 0–16 scale; robust standard errors are reported in the parentheses, and are clustered at the highest-level geographic administrative divisions such as metropolitan cities and provinces. *** stands for p-values less than 0.001; ** stands for p-values less than 0.01; * stands for p-values less than 0.05. KRW stands for Korean Won. Alt. def. stands for alternative definition, which uses functional difficulty measures instead of government registration status.

Chronic conditions and interaction with disability

Having a chronic condition(s) was negatively associated with health literacy independent of disability status (Table 2, Model 3). The presence of a chronic condition(s) alleviated the lower health literacy scores of people with disabilities (Table 2, Model 4). This interaction suggests heterogeneity in the disability-health literacy association by healthcare exposure, a pattern that is consistent with learning/familiarity mechanisms discussed below.

Sensitivity analyses using an alternative disability definition

The alternative disability definition identified an additional 1477 individuals as having a disability, while 315 of the 793 people with government-registered disabilities did not report any limitations in mobility, self-care, or usual activities. It should also be noted that a considerable proportion of individuals with government-registered disabilities did not respond to the EQ-5D items. The non-response rate was 10.71% among people with a registered disability, which was significantly higher than that among people without a registered disability (6.49%, p < 0.001). Among respondents for whom the alternative definition could be applied, the health literacy scores of individuals classified as having a disability were an average of 1.49 points lower than those of individuals without a disability (Table 2, Model 5). This is notably larger than the difference of 0.94 points estimated when disability was defined according to government registration status (Table 2, Model 1). The larger disparity under the functional-limitation definition suggests that the implied severity/composition of the “disability” group differs across definitions, which has implications for both interpretation and measurement. At the same time, comparisons across definitions should be done with caution because differential non-response to the EQ-5D items may bias estimates, particularly if non-response is related to health literacy.

Discussion

Previous research using the KHPS dataset showed that Korean adults, regardless of disability status, have low health literacy compared with their international peers²². Furthermore, another study utilizing the same instruments as the KHPS auxiliary survey (HLS-EU-Q16) found similarly low scores among older Korean adults²³. Our study reveals that adults with government-registered disabilities have even lower health literacy than those without disabilities. Guided by Sørensen et al.’s health literacy model, we interpret these low levels as reflecting not only individual competencies but also the broader social and health-system context, and we use this lens to discuss why disparities may differ across disability types. Notably, however, the estimates need to be understood as associations rather than causal effects, given the cross-sectional nature of the study.

As shown in prior research^31,32, health literacy is positively associated with education and income, both of which may be adversely affected by disability. This is consistent with the view that health literacy is shaped by both personal and societal determinants. However, our results indicate that adults with disabilities exhibit lower health literacy even when education and income levels are controlled for. These unexplained differences suggest that individuals with disabilities face distinct barriers in accessing, understanding, and using health-related information. Residual differences may also reflect underlying factors such as early-life socioeconomic conditions, community resources on schooling, accessibility of health information and services which would have affected both the health literacy level and management of disabilities.

Not all types of disabilities impose the same level of burden on an individual’s ability to become health literate. We found that individuals with cognitive limitations had the lowest health literacy, followed by those with sensory impairments such as hearing or vision loss. By contrast, individuals with impairments of external body structures or internal organs did not appear to experience disadvantages in health literacy. One possible explanation is that sensory impairments may restrict access to health information^7,33. Despite recent developments in assistive technologies, differences in the modes of communication preferred by or available to individuals according to disability type may further contribute to disparities in information accessibility. Information on whether survey participants used any type of assistive technology in everyday life or while answering the questionnaire was not available, limiting our understanding of this issue. For individuals with cognitive disabilities, the primary barrier may lie in understanding and evaluating information, even after it has been accessed.

Several features of measurement and sample selection may also influence both the magnitude and the interpretation of the observed disparities, as discussed below. First, participation in the health literacy module differed substantially by disability type, suggesting that the measured scores may be conservative for groups facing the greatest communication or information-processing barriers. Second, disability classification depends on administrative processes such as government registration, which may leave individuals and communities with fewer resources less likely to be registered and more likely to have lower health literacy, thereby potentially confounding the analyses. Third, the discrepancy between the groups identified as having disabilities under alternative definitions invites further investigation into how health literacy, functional difficulties, and management of one’s conditions are interconnected.

The health literacy levels reported in this study may overestimate the true health literacy of adults with cognitive disabilities. Survey participation rates varied according to disability type and appeared to correlate with measured health literacy levels. For example, 34% of individuals with cognitive impairments and 15% of individuals with hearing limitations declined to participate in the health literacy module, whereas refusal rates were only 4%, 3%, and 1% among individuals with external body impairments, internal organ impairments, and vision limitations, respectively (Supplementary Table S2). This suggests that non-response may have been driven by difficulty comprehending the survey’s purpose or content, rather than a lack of interest. In support of this interpretation, a national survey of individuals with developmental disabilities in Korea, called the Survey on the Work and Life of Persons with Developmental Disabilities, reported that 29% of sampled individuals were unable to answer any survey questions, even when aided by graphic symbols or easy-to-read texts³⁴. Taken together, these findings suggest that the observed disparities in health literacy are likely conservative estimates, particularly for adults with cognitive disabilities, because selective non-response may have excluded individuals with the lowest underlying health literacy.

Another source of potential bias is the inclusion of individuals with disabilities who meet the medical criteria for government registration but remain unregistered. In some cases, individuals may lack the resources or access necessary to complete the registration process. In other cases, individuals may forgo registration because they can function relatively well despite their conditions. Consequently, the inclusion of unregistered individuals in the study sample may have influenced our estimates in either direction. While a few studies have attempted to estimate the number and characteristics of people with unregistered disabilities in Korea³⁵, the existing evidence is limited, which makes it difficult to predict the direction or magnitude of their impact on our estimates.

Finally, the construction of the health literacy measure also warrants consideration. In our analysis, “I don’t know” responses on the HLS-EU-Q16 were coded as 0 rather than treated as missing. Although this differs from standard scoring approaches, item non-response in our sample was similar by overall disability status, and the distribution of missing item counts did not significantly differ across disability types (chi-square p = 0.46). This suggests that our handling of “I don’t know” responses is unlikely to fully explain the observed group differences, although some measurement bias cannot be ruled out.

Chronic medical conditions may help mitigate lower health literacy among adults with disabilities. Although we found that the presence of chronic conditions was negatively correlated with health literacy scores regardless of disability status, this negative association is considerably attenuated among people with disabilities. Considering that nearly 85% of adults with disabilities in our sample reported having at least one chronic condition, this attenuation is substantial. We suspect that repeated interactions with the healthcare system help individuals with disabilities become familiar and confident in managing their conditions and health, as suggested by other studies of individuals with long-term medical conditions^36,37. However, given the cross-sectional design, reverse causality cannot be ruled out. Individuals with higher baseline health literacy may have been more active in obtaining diagnoses and in reporting chronic conditions. Although further investigation is needed, repeated exposure to healthcare-related concepts and practices could be a key element in future programs aimed at improving health literacy among people with disabilities.

Our findings, which are based on two definitions of disability, namely, government registration and self-reported functional difficulties in daily activities, have important implications for both policy and academic research. Notably, nearly half of the individuals in our sample with government-registered disabilities reported minimal or no limitations in daily functioning, suggesting that appropriate societal support can mitigate the perceived burden of disability. At the same time, this discrepancy raises concerns that a substantial number of individuals who do require assistance in daily life may not be formally identified through the registration system.

The regression results further underscore this point: the negative association between disability and health literacy is even stronger when disability is defined by self-reported functional limitations. A large proportion of individuals with government-registered disabilities could not be included in the analyses because they did not answer EQ-5D items and therefore could not be classified under the functional limitation definition. These individuals are more likely to have lower health literacy than those without registered disabilities and therefore their exclusion may have decreased the observed difference in health literacy. Furthermore, the survey items assess functional status “as of today” and therefore the alternative definition may also capture individuals who are experiencing only temporary limitations. This suggests that the true disparity in health literacy between people with and without enduring disabilities may be even larger than our estimates indicate.

These findings underscore that both the number and characteristics of individuals identified as having a disability vary considerably depending on the definition used. The sharper disparity in health literacy when using the self-reported functional limitation definition reinforces the argument that Korea’s current criteria for disability registration may require revision to be more inclusive. In the meantime, researchers relying on the registration-based definition should be mindful of its potential limitations.

Unlike many existing studies of health literacy among people with disabilities, which often rely on small convenience samples or secondary datasets that do not permit detailed analysis according to disability type, this study draws on a nationally representative survey. The dataset includes rich information on respondents’ health status, type of disability, and a validated, internationally recognized health literacy instrument. We quantified the magnitude of disparities in health literacy between people with and without disabilities and showed that the size of this difference varies significantly according to disability type. In addition, our findings suggest several potential intervention points, such as the importance of repeated exposure to health information and greater attention to functional limitations rather than relying solely on legal or diagnostic categories.

Low health literacy is associated with a range of adverse health outcomes, including lower rates of cancer screening, lower medication adherence, higher hospitalization and mortality rates^38–40, and difficulties and dissatisfaction when communicating with healthcare providers⁴¹. Health literacy is therefore essential for self-advocacy and effective healthcare navigation, particularly for people with disabilities, who often face additional barriers to care⁴². Interventions should incorporate self-reported functional difficulties to identify individuals at risk, in addition to using legal or administrative definitions of disability. It is also important to understand the distinct challenges associated with each type of disability when addressing disparities in health literacy. In the future, we plan to explore these challenges further and develop strategies to improve health literacy more broadly.

Conclusion

In a nationally representative Korean sample, adults with government-registered disabilities had substantially lower health literacy than those without disabilities, and the magnitude of the gap varied markedly by disability type, with the largest differences observed for cognitive and hearing limitations. Results were sensitive to how disability was defined, underscoring the importance of measurement choices and the potential role of selection into survey participation and administrative classification. Although the analysis is cross-sectional and cannot establish causality, the findings suggest possible intervention targets, including reducing communication and accessibility barriers, tailoring support to disability-specific needs, and considering functional limitations in addition to registration status when identifying potentially at-risk individuals.

Supplementary Information

Below is the link to the electronic supplementary material.

Author contributions

EYY conceptualized the study design, acquired and analyzed the data, and wrote the original and subsequent drafts of the manuscript. SP acquired funding for the project, conceptualized the study design, and supervised the research topic. IO reviewed and edited the manuscript and advised on the study design and interpretation of the analysis results. All authors read and approved of the final manuscript.

Funding

This research was funded by a grant from the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (grant number: HI21C2122).

Data availability

The Korea Health Panel Survey is available for free upon request to the data coordinator.

Declarations

Ethics approval and consent to participate

The Kyung Hee University Institutional Review Board approved this study [KHUIRB-24-191]. We were exempted from requirements for informed consent because this study involved secondary analysis of de-identified survey data.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.