Health Literacy: Why It Matters and What Healthcare Can Do About It

Health literacy, broadly defined as the ability to obtain, process, and understand basic health information and services needed to make appropriate health decisions, is among the most consequential but least recognized social determinants of health. Approximately one in three American adults have limited health literacy, meaning they struggle to navigate healthcare systems, understand medication instructions, interpret lab results, or communicate effectively with healthcare providers. The consequences for health outcomes, healthcare costs, and health disparities are substantial. Research documents consistent associations between limited health literacy and worse health outcomes across conditions and populations. Adults with limited health literacy are more likely to misuse medications, less likely to receive preventive care, more likely to be hospitalized, more likely to have difficulty managing chronic conditions, and more likely to experience adverse drug events. The estimated additional healthcare costs associated with limited health literacy are significant, suggesting that investment in health literacy improvement could produce substantial savings in addition to better health outcomes. Health literacy operates at both individual and systemic levels. Individual health literacy reflects reading skills, numeracy, and the knowledge and skills needed to navigate healthcare contexts. Systemic or organizational health literacy refers to the degree to which health systems and organizations make their services, information, and communications easy for all people to understand and use. Focusing exclusively on individual health literacy, while ignoring the complexity and inaccessibility of healthcare communication, places the burden on patients rather than on systems that could be redesigned to be more accessible. Plain language principles, which involve writing health materials at accessible reading levels, using common words instead of medical jargon, organizing information clearly, and using white space and headers to aid comprehension, significantly improve health communication effectiveness. Research on plain language health materials documents that they are better understood by patients across literacy levels, not only by those with limited literacy. Despite evidence for plain language effectiveness, most health materials in use exceed the reading level recommended for broad comprehension. Teach-back is an evidence-based communication technique in which providers ask patients to explain in their own words what they have been told about their condition, medications, or care plan, rather than simply asking whether they understand. Research on teach-back consistently finds that it identifies misunderstandings that patients would not have volunteered and improves medication adherence, disease self-management, and care plan compliance. Its implementation requires training and cultural change in clinical settings but has been adopted in a growing number of healthcare systems. Numeracy, the ability to understand and use numerical health information, is a specific dimension of health literacy with significant implications for medication management, risk communication, and shared decision-making. Research documents that many patients, even those with adequate general literacy, struggle with the numerical information routinely used in healthcare, including medication dosing instructions, risk percentage information, and laboratory value interpretation. Communication designs that use pictographs, frequency formats, and natural language rather than percentages improve numeracy comprehension. Electronic health records and patient portals have created new opportunities for patient engagement with health information but have also created new literacy demands. Research on patient portal use finds that patients with lower health literacy use portals at lower rates and derive less benefit from them. Designing patient-facing technology with health literacy principles, including plain language, clear navigation, and support for users with varying digital and health literacy, is an ongoing challenge for health systems. Community health workers, who are trusted community members with shared cultural and linguistic backgrounds with the populations they serve, are an evidence-based resource for improving health literacy in communities where literacy, language, and cultural barriers to healthcare are most significant. Research on CHW programs documents improvements in chronic disease management, preventive care utilization, and health outcomes in populations that CHWs serve. Integrating CHWs into healthcare teams and providing sustainable funding mechanisms for their roles represents an important strategy for addressing health literacy disparities.