More than a reading test: rethinking health literacy through a behavioral science lens

A patient leaves an appointment nodding. They say they understood. They take the leaflet. Two weeks later, they’re taking their medication at the wrong time. They haven’t booked the follow-up. They’ve stopped logging into the patient portal because they can’t remember the password or why it mattered.

It’s tempting to call this a patient problem: low health literacy, poor adherence, disengagement. But a more useful question than “Why didn’t they understand?” might be, “What did we ask of them, and did we do so as clearly and actionably as possible?”

The scale of the challenge

In 2023, 28% of US adults scored at the lowest level of literacy in the OECD Survey of Adult Skills; on numeracy, 34% scored at the lowest level¹. Across 17 European countries, between 25% and 72% of adults have limited health literacy, depending on the country². Low health literacy is consistently linked with poor outcomes, such as more hospitalizations and use of emergency care, and worse ability to demonstrate taking medications appropriately³.

Most written patient information, however, is above the commonly recommended sixth- to eighth grade reading level (with some guidance recommending even lower), with no improvement between 2001 and 2022⁴. Information is easily forgotten. In one study, less than half (49%) of decisions and recommendations made in outpatient encounters were recalled accurately, without prompting, a week later⁵.

For example, one study showed that health literacy interventions improved treatment adherence, with bigger gains among lower-income and marginalized communities⁶.

Health literacy is a shared responsibility

Definitions of health literacy have changed a lot over the past 25 years. Early models focused on functional skills, like reading a medication label or working out a dose. Today’s definitions also cover motivation, interaction, and the systems people must navigate^7,8. The Healthy People 2030, the Health and Human Services 10-year national initiative for improving health in the US, makes shared responsibility explicit by separating personal health literacy from organizational health literacy: the degree to which organizations equitably enable people to find, understand, and use information and services^9,10.

In designing for health literacy, we look at four core domains of ability:

• Cognition: Applying skills such as reading, writing, and numeracy, along with higher-order skills like critical decision-making.
• Interpersonal skills: Discussing health topics and engaging confidently with peers, healthcare professionals, and the wider health system.
• Individual behavior: Accessing, understanding, interpreting information, turning it into action, such as managing medications and following a treatment plan.
• System navigation: Finding a way through complex settings and processes, such as referrals and health insurance.

From understanding to action

Too often, health literacy is treated as a readability check at the end of the process: run a reading-level score, swap a few long words, approve. This is a worthwhile but insufficient step, covering just one part of one domain.

Cognitive load is the mental effort needed to process information, and our capacity for it is limited. can bring high load. When load is high, even “simple” information is harder to take in, remember, and act on, and we often lean more heavily on mental shortcuts that can lead us astray. In their hardest moments, patients need more than plain language. They need materials and interventions that are designed to optimize their understanding and their ability to take action as they navigate their individual needs in an overwhelming healthcare system

An approach that CARES

To meet this reality with an understanding of what it takes to ensure both comprehension and action, built HL:CARES, a proprietary, human-centered, and evidence-based framework.

• Human-centered: Built around patients’ needs, goals, and desires. For example, co-create with and get feedback from patients, and ensure understanding of needs, goals, and concerns before creating materials.
• Literacy improvement: Builds skills across the health literacy domains rather than only working around gaps. For example, give people simple tools to track symptoms and questions, or using evidence-based literacy interventions such as teach-back (i.e., asking people to explain in their own words what they have heard and what they will do).

CARES puts this approach into practice:

• Clear: Use plain language, explain complex terms, and help people see key ideas at-a-glance. For example, expressing risk as an absolute frequency (e.g., “3 out of 100 people”) instead of vague words like “rare” or “likely,” and using simple, striking visuals with one main takeaway (e.g., an icon array showing outcomes for 100 people).
• Actionable: Set specific actions and summarize next steps so they’re easy to recall. For example, putting the most important message first, making actions explicit and time-bound (e.g., “Book your blood test by Friday”), and closing with a summary of takeaways and next steps.
• Relevant: Reflect people’s own lives, language, and experiences, including where they are in their journey, so they can see themselves in the material. For example, using real-life scenarios tailored to the moment, imagery and language the audience identifies with and uses, as well as narrative and storytelling.
• Empowering: Encourage and enable measurable behavior change by building confidence and motivation to act. For example, breaking complex tasks into small, doable steps, which enables incremental successes to build confidence.
• Structured: Organize into well-defined topic areas and digestible chunks of information. For example, keeping to one clearly headlined idea per section, using bullets instead of long paragraphs, and splitting lists longer than seven items.

Five tips for designing beyond the materials

What a resource says and how it looks is only part of the picture. Lasting health literacy improvement also depends on how interventions are developed, delivered, and sustained:

1. Design with, not just for, patients: Patients are experts in their own experience. To reiterate the core human-centricity principle above, there is no replacement for engaging with the people who you are trying to support directly.  Get their input and feedback early and throughout where possible, and co-create so that their language and perspectives are reflected.
2. Measure before you design: Validated tools exist for different purposes, covering reading and numeracy, communications skills, digital health literacy, and how ready an organization is. The right tool depends on what you need to learn, but many tools are available to assess where a population’s literacy gaps are and where to focus intervention efforts.
3. Address emotion as well as behavior: A useful first step is to acknowledge how someone is feeling. Once people feel heard and validated, a behavioral approach to building engagement is more likely to work.
4. Go multichannel and reinforce: The most successful interventions combine face-to-face, written, visual, and digital channels and repeat key actions across them. The teach-back method described above can be used to further cement understanding and empower action.
5. Make it organizational: Health literacy shouldn’t live in a silo. That means training staff, building health literacy into policies and processes, and running organizational self-assessments. It also means adopting a “universal precautions” mindset: assume anyone may have difficulty understanding and design for that.

Health literacy is designed, not just possessed

This Health Literacy Month, pharma and biotech teams have a chance to change the question. Instead of asking whether patients are health literate enough, ask whether our materials, programs, and systems are. When we design for how people actually think, feel, and act, especially on their hardest days, we give people a far better chance of turning information into action, and thus improved outcomes.

 

References

1. National Center for Educational Statistics.“ Highlights of the 2023 U.S. PIAAC Results. U.S. Department of Education.” (accessed October 27, 2026).
2. The HLS19 Consortium of the WHO Action Network M-POHL. “International Report on the Methodology, Results, and Recommendations of the European Health Literacy Population Survey 2019-2021 (HLS19) of M-POHL.” (accessed October 27, 2026).
3. Berkman ND, et al. “Low health literacy and health outcomes: an updated systematic review.” Annals of Internal Medicine. (2011). 155(2):97–107. https://doi.org/10.7326/0003-4819-155-2-201107190-00005
4. Okuhara T et al . Readability of written information for patients across 30 years: a systematic review of systematic reviews. 2025). Patient Education and Counseling, Volume 135, (2025). 135:108656.  https://doi.org/10.1016/j.pec.2025.108656
5. Laws M, et al. Factors associated with patient recall of key information in ambulatory specialty care visits: Results of an innovative methodology. PLoS One. (2018) 1;13(2):e0191940. https://doi:10.1371/journal.pone.0191940.
6. Miller TA. Health literacy and adherence to medical treatment in chronic and acute illness: a meta-analysis. Patient Education and Counseling. (2016). 99(7):1079–1086. https://doi.org/10.1016/j.pec.2016.01.020.
7. Nutbeam D. Health literacy as a public health goal. Health Promotion International. (2000). 15(3):259–267. https://doi.org/10.1093/heapro/15.3.259.
8. Sørensen K, et al. Health literacy and public health: a systematic review and integration of definitions and models. BMC Public Health. (2012). 12:80. https://doi.org/10.1186/1471-2458-12-80
9. Office of Disease Prevention and Health Promotion (ODPHP). Health Literacy in Healthy People 2030. (accessed October 27, 2026).
10. Santana S, et al. Updating health literacy for Healthy People 2030: defining its importance for a new decade in public health. J Public Health Manag Pract. (2021). 27(Suppl 6):S258–S264. https://org/10.1097/PHH.0000000000001324.
11. Baxter KA, et al. The Application of Cognitive Load Theory to the Design of Health and Behavior Change Programs: Principles and Recommendations. Health Education & Behavior , (2025). 52(4):469-477. https://doi.org/1177/10901981251327185.