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Patients with Low Health Literacy Make More Errors Interpreting Instructions and Warnings

Problem: Whether limited by knowledge, socioeconomic factors, emotional or clinical state, or cultural background, the patient’s level of health literacy—the ability to read, understand, and act in a well-informed manner on healthcare information—is often dangerously low. This issue is compounded by the fact that healthcare information is increasingly available via digital healthcare portals. According to the US Department of Education, National Center for Education Statistics (NCES), National Assessment of Adult Literacy (NAAL), more than half of adults (53%) are classified as having intermediate health literacy, followed by basic (22%), and below basic (14%), with only a small percentage (12%) considered health literacy proficient. People who have difficulty reading or understanding health information may be embarrassed and hide the problem, often masking underlying fear due to the misunderstanding. In addition, low health literacy is often not obvious, and practitioners may not be aware that some patients need additional support to understand their care plan. Also, researchers have reported poor reading skills in some of the most poised and vocally articulate patients. Most patients need help understanding information about their health and medications regardless of their level of intelligence, ability to read or write, or reading comprehension. 

Definition of health literacy

Healthy People 2030, an initiative led by the Centers for Disease Control and Prevention (CDC), describes health literacy in terms of both personal and organizational aspects. They define personal health literacy as the degree to which individuals can find, understand, and use information and services to inform health-related decisions and actions for themselves and others. Healthy People 2030 defines organizational health literacy as the degree to which organizations equitably enable individuals to find, understand, and use information and services to inform health-related decisions and actions for themselves and others. Patients should be able to make “well-informed” decisions rather than “appropriate” ones. These definitions emphasize the patient’s ability to use health information rather than just understand it, and acknowledge that organizations have a responsibility to address health literacy with everyone.

Problems with low health literacy

Patients with low health literacy are more likely to make errors when interpreting medication instructions and warning labels.1 This is especially true when instructions involve a titration or taper. Not understanding how to take the medication may result in taking a sub-optimal dose or overdose of medication, which can lead to an increased risk of adverse events.2 Low health literacy can also contribute to decreased medication adherence.3 Furthermore, patients who do not understand their disease state and how medication can help, may be less likely to take their medication as prescribed to minimize disease progression or complications.4 

Organizations and individual practitioners may not have the proper resources to help assess or support varying levels of health literacy in patients they treat. To complicate the matter, medical information is difficult to understand even for patients whose primary language is English. Comprehension of medical language is even more difficult for patients with limited English proficiency (LEP) who may struggle with both linguistic and other cultural barriers. Due to time constraints, lack of available interpreters, or convenience, practitioners may choose to “get by” without an interpreter.5 Staff may use family members, friends, or even colleagues as interpreters, but these people may not have the ability to understand or translate the information appropriately in medical terms. 

Errors related to health literacy

Below are recent events reported to ISMP that involve gaps in health literacy:

A Spanish-speaking patient misinterpreted the directions (in English) for DisposeRx (Figure 1), a product intended to facilitate safe drug disposal. The patient thought the contents were to be ingested, partly due to the photo on the packet of the powder being dispersed in what looked like a glass of water. Fortunately, a home care nurse who was counseling the patient using a Spanish-language interpreter intercepted the error.

Figure 1. A patient thought they were supposed to ingest the contents of the DisposeRx packet, in part due to the picture on the packet.
Figure 1. A patient thought they were supposed to ingest the contents of the DisposeRx packet, in part due to the picture on the packet.

A non-English speaking patient was discharged from a hospital with a new prescription for albuterol 2.5 mg/3 mL nebulization solution. During a post-discharge phone call, the patient told a nurse that she had been given a liquid medication to drink from a “syringe.” The nurse contacted the patient’s pharmacy and realized that the patient was drinking the albuterol from the plastic container (Figure 2), which the patient had described as a “syringe.”

Figure 2. Albuterol nebulization solution comes in a plastic container that is to be used with a nebulizer machine for inhalation. The patient referred to it as a “syringe” and drank the contents.
Figure 2. Albuterol nebulization solution comes in a plastic container that is to be used with a nebulizer machine for inhalation. The patient referred to it as a “syringe” and drank the contents.

Safe Practice Recommendations: Health literacy has a critical impact on informed decision-making, including safe medication use. Consider the following recommendations to support both personal and organizational health literacy. 

Assess literacy level. As part of the admission process, consider the use of assessment tools. The Test of Functional Health Literacy in Adults (TOFHLA) and the Rapid Estimate of Adult Literacy in Medicine (REALM) are the most widely used instruments to measure health literacy.   

Provide health literacy-friendly materials. Organizations should strive to offer written materials (e.g., medication handouts, prescription labels) in the patient's preferred language, at a fifth grade reading level or lower. Simplify materials and offer small amounts of information at a time. Use clear captions, pictures, diagrams, or videos to help explain concepts. Most patients, even those who read well, depend on visual clues to reinforce learning and spark memory. Consider using the Patient Education Materials Assessment Tool (PEMAT) to evaluate how understandable and actionable medication education materials are to the general public. To promote better patient understanding of labeling instructions and information on prescription containers, review the USP, General Chapter <17> Prescription Container Labeling (December 1, 2021).

Gather feedback. Seek feedback from patients (e.g., focus groups, targeted satisfaction survey questions), patient advocates, and healthcare educators to ensure that written materials effectively communicate the most vital information in concise, familiar language, and update as necessary. 

Provide patients with tools. Provide resources to prepare patients on how to be more involved in their health including their medication regimens. Make medication education information available for patients within an online portal, via a smartphone application, and/or via handouts. Ensure information on the patient portal is patient-friendly, especially if making highly technical documents available digitally (e.g., CT scan summary interpretation by a radiologist, echocardiogram results written by a cardiologist).

Offer language services. Make formal interpreter services available, including in person, by video call, and/or by telephone. Interpreter services benefit not only the patient but also staff members who otherwise struggle to ensure the provision of high-quality care. Use caution with interpretation services from multilingual teammates, or family members of the patient, who may not be well-versed in healthcare translation. Ensure any communication past conversational discussions involves a trained professional.

Document in the EHR. Build required fields to document preferred patient language and interpreter service needs in the electronic health record (EHR). Ensure this information is easily accessible to staff. Automatically schedule interpreters at clinical points of service for patients who are identified with LEP. 

Educate patients. Implement the teach-back method and have patients show and tell how they plan to take their medications. Avoid closed-ended questions and never assume patients understand how to take their medications. Do not assume being articulate and confident equates to adequate reading skills and other proficiency. Patients who cannot read will likely try to mask their lack of skill due to emotional reasons (e.g., embarrassment) or misunderstanding of the potential negative impacts on their care. Empower patients and families to report errors through the ISMP consumer website, so they can contribute to learning. 

Coach practitioners. Instruct staff about best practices involving disease and medication information communication, interpreter service use, and cultural awareness. Create a policy or procedure for practitioner onboarding to ensure staff are aware of the available resources and when to use them. To minimize language barriers, the Agency for Healthcare Research and Quality (AHRQ) has several training programs available, including the TeamSTEPPS (Team Strategies and Tools to Enhance Performance and Patient Safety) LEP Module.   


  1. Wolf MS, Davis TC, Tilson HH, Bass PF 3rd, Parker RM. Misunderstanding of prescription drug warning labels among patients with low literacy. Am J Health Syst Pharm. 2006;63(11):1048-55.

  2. Zhang NJ, Terry A, McHorney CA. Impact of health literacy on medication adherence: a systematic review and meta-analysis. Ann Pharmacother. 2014;48(6):741-51.

  3. Fox D, Rowlands G, Kapadia N, Chinemana F, Ubhi V, Shaw A. The impact of low literacy on patient health: a qualitative study of United Kingdom primary care practitioners' views. Health Issues. 2007;92:15–19.

  4. Orom H, Schofield E, Kiviniemi M, et al. Low health literacy and health information avoidance but not satisficing help explain don’t know responses to questions assessing perceived risk. Med Decis Making. 2018;38(8):1006-17. 

  5. Diamond LC, Schenker Y, Curry L, Bradley EH, Fernandez A. Getting by: underuse of interpreters by resident physicians. J Gen Intern Med. 2009;24(2):256-62.


Suggested citation:

Institute for Safe Medication Practices (ISMP). Patients with low health literacy make more errors interpreting instructions and warnings. ISMP Medication Safety Alert! Acute Care. 2023;28(24):1-3.