Does health literacy affect health outcomes more than access to care?

How big is the impact of health literacy compared to access to care?

Health literacy—the ability to find, understand, and use health information—has a surprisingly large effect on health outcomes, often larger than whether someone has insurance or a regular doctor. In a study of over 1,300 patients, those with inadequate health literacy had hearing loss that was, on average, 5.38 decibels worse at their first appointment compared to those with adequate literacy, even after adjusting for age, education, and insurance type [10]. That means they waited longer to seek care, letting the problem worsen, despite having similar access to the healthcare system. Similarly, in a cohort of hospitalized patients, those with inadequate health literacy were three times more likely to return to the emergency department within 90 days of discharge, regardless of their education level or insurance status [2]. These effects are not small—they translate into real differences in disease severity, hospital use, and quality of life.

Access to care, on the other hand, is also critical but often works through different pathways. In a large Canadian survey, over half of respondents who sought mental health care faced barriers like long waitlists (62%) and financial costs (58%) [5]. These structural barriers prevented people from getting care at all. But even when people have insurance, health literacy still predicts whether they get preventive services like cancer screenings. Among Korean Americans, 79% had health insurance, yet only 11.6% felt confident filling out medical forms, and cancer screening rates were far below national targets—suggesting that having coverage alone does not guarantee use [4]. The evidence suggests that health literacy and access are not competing factors; they interact. Poor health literacy can make access meaningless, and poor access can make health literacy irrelevant.

How does health literacy actually cause worse health?

Health literacy affects health through multiple pathways: it influences whether people seek care early, how well they manage chronic conditions, and whether they adopt healthy behaviors. In a study of menopausal women, those with low health literacy were more than four times as likely to smoke and more than six times as likely to have depression, compared to those with adequate literacy [8]. These are not just correlations—the study controlled for age and education, suggesting health literacy itself drives these behaviors. Similarly, among spine surgery patients, those with limited health literacy scored worse on every measure of physical function, pain, and mental health, even after adjusting for income, education, and insurance type [3]. This pattern holds across diverse populations: in a study of LGBTQ adults in Lebanon, adequate health literacy was significantly associated with higher rates of STI testing and lower rates of chronic disease [1].

One key mechanism is that low health literacy makes it harder to navigate the healthcare system. People with low literacy are less likely to understand when they need care, how to make appointments, or how to follow treatment plans. In a study of people with HIV, those with inadequate health literacy were more likely to need coaching from community health workers just to manage their care [6]. This extra support can help, but it also means that without it, these patients are at higher risk of poor outcomes. The evidence is clear: health literacy is not just a marker of disadvantage—it is a root cause of disparities in health.

Are there situations where access to care matters more than health literacy?

Yes, access to care can dominate in specific contexts, especially when financial or structural barriers are extreme. In a study of hearing aid adoption, health literacy was not associated with whether people actually got hearing aids—only the severity of hearing loss and having Medicaid coverage mattered [10]. This suggests that when the cost of care is prohibitive, even people with good health literacy cannot act on it. Similarly, in a study of families in Mexico, limited access to healthcare was directly linked to higher rates of youth substance use, independent of parents' health literacy [7]. In these cases, the barrier is not understanding—it is availability and affordability.

However, even when access is improved, health literacy still matters. In Croatia, where universal healthcare exists, people with limited health literacy still reported higher rates of unmet medical needs, largely due to long waiting lists [9]. This suggests that low health literacy makes it harder to navigate even a well-funded system. The two factors are not a simple trade-off; they are intertwined. Improving access without addressing health literacy leaves many people unable to use the care they have, while improving health literacy without fixing access barriers leaves people with knowledge but no way to act.

About These Sources

This answer is built on 10 peer-reviewed studies — published from 2021 to 2025, 2 from 2024 or later, 4 in Q1 journals, collectively cited 428 times — selected as the most relevant from 11 studies that passed quality screening, drawn from 52 papers retrieved from a database of over 500 million.

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