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Evidence Reviews and Research Summaries

Here you will find the most recent evidence report on health literacy interventions and outcomes and brief research summaries on health literacy topics.

Health Literacy Evidence Reviews

Health Literacy Interventions and Outcomes: An Updated Systematic Review. The Agency for Healthcare Research and Quality (AHRQ) summarizes the evidence on health literacy and outcomes in a systematic review.

Research Summaries on Health Literacy Topics

CDC is committed to applying and sharing research to improve health literacy. In our Research Summaries section we present findings from recent published studies focused on specific health literacy topics. See our Science Bites for very brief summaries of select findings and recommendations for practice. Use these summaries to improve the effectiveness of your communication and program activities.

Health care professionals’ use of health literacy-based communication techniques

Patients need health care providers who can communicate clearly. Goal 2 of the National Action Plan to Improve Health Literacy outlines strategies all health professionals can use to identify and address health literacy barriers that negatively affect patient care and individual and community health outcomes.

Clinical professionals such as dentists, pharmacists, nurses, and physicians have an especially important role in improving health literacy and implementing strategies from the Action Plan.   This brief summary of research from 2011 to 2014 describes the use of health literacy-based communication strategies by health care professionals.

Dentists and Dental Hygienists

In a 2011 study, two-thirds or more of dentists reported using four communication techniques to ensure effective communication with patients and their understanding of oral health information.  These techniques include handing out printed materials, speaking slowly, using models or radiographs to explain, and using simple language.

These results were from a national survey to determine how frequently dentists use 18 communication techniques. The most commonly used technique was using simple language (90%). Teach-back techniques such as having the patient repeat information and repeat instructions were used by less than 24% of surveyed dentists.

A 2013 study of Maryland dentists found similar results. Over 93% of general dentists reported using simple language always or most of the time.  Teach-back techniques were much less used, with only 19% of general dentists asking patients to repeat information or instructions, and 35% asking patients to tell them what they will do at home to follow instructions. Pediatric dentists were more likely to ask patients to tell them what they will do at home to follow instructions (50%).

Results from health literacy environmental scans of community-based dental clinics are reported in a 2014 study.  One component of these scans involved assessing the frequency of dentists’ and dental hygienists’ use of recommended communication techniques. Use of teach-back was low.  Only 7% of providers indicated that they “always” use this technique; 22% indicated they use it “most of the time”; and 33% use it “occasionally”.   Techniques reportedly used “most of the time” or “always” include:

  • Limit number of concepts presented at a time to 2-3 (87%)
  • Use models or x-rays to explain (87%)
  • Use of simple language (99%)
  • Use a translator or interpreter when needed (75%)


Nurses’ use of communication techniques in encounters with type 2 diabetes patients was assessed in a nine-nurse qualitative 2014 study. Two to four encounters were recorded per nurse. Clarifying health information was the most commonly applied technique (58% often used), followed by repeating health information (33% often used). Checking for understanding was the least applied (81% never used), followed by asking for understanding (42% never used). Medical jargon and mismatched language were often used in 17% and 25% of the encounters, respectively.

Nurse practitioners’ knowledge, experience, and intention to use health literacy strategies were investigated in a 2013 study. The results show that overall knowledge of health literacy and health literacy strategies was low. Screening patients for low health literacy and evaluating patient education materials were found to be areas of knowledge deficit.  However, nurses’ intention to use health literacy strategies in practice was found to be strong.


In a 2013 pilot study, older adult patients reported on pharmacists’ use of health literacy-based techniques. The results are by proportion of patients reporting pharmacists’ behavior when the patient filled a new prescription.  

  • 89% of spoke to patients about how to take their medication
  • 84% spoke to patients about side effects
  • 47% discussed the problem for which the medication was prescribed
  • 26% communicated a plan for taking medications as prescribed
  • 39% explained what may happen if the medication is not taken as prescribed
  • 21% asked patients  to explain how they were going to take their medicine
  •  0% asked patients  to demonstrate how they were going to use their medicine


Results from a 2013 study reveal differences between medical residents’ self-reported communication behaviors and observed behaviors.   Residents reported frequent use of plain language (88%) and teach-back (48%).  However, their actual use of these techniques observed during low health literacy standardized patient encounters was much lower.  Residents used an average of two jargon terms per minute, and only 22% used teach-back.

Similar results were found in a 2013 study of medical resident’s communication with newly admitted patients to the emergency room.  Medical students observed internal and family medicine residents while they admitted patients to medical service in the emergency room.  Students used a checklist to assess interactions between residents and patients over an 8 week period.

In 52% of these interactions, residents used medical acronyms when communicating with patients.  Technical medical terms or expressions were used during the history taking in 66% of interactions, and less than 28% of those interactions included at least a partial explanation of terms.  Teach-back was not observed in any of the observed interactions.  Residents for whom English is a second language (ESL) used significantly more technical language than native English speaking residents, while native English speaking residents tended to use more acronyms.

A 2012 study of emergency physicians found the use of simple language and speaking slowly to patients as the only techniques a majority said  they used routinely  (92% and 61%, respectively). When asked about their perceptions of the effectiveness and feasibility of eight different communication techniques (shown below), a majority ranked all but “Reading aloud instructions” as effective, and the physicians said all eight were feasible in the emergency department.  

  • Using simple language
  • Speaking slowly
  • Underlining key points in patient information handouts
  • Presenting two concepts at a time and checking for understanding
  • Drawing pictures or using models to explain concepts
  • Reading aloud instructions
  • Asking patients how they will follow instructions at home
  • Asking patients to repeat information, teach-back technique

A 2014 study of radiation oncologists explores their understanding and awareness of health literacy among patients, their views regarding health literacy, and identifies techniques they use to communicate to different literacy populations. Participating oncologists report subjectively assessing a person’s literacy level by:

  • Monitoring the types of questions asked
  • Analyzing the language used
  • Examining non-verbal behavior
  • Considering a person’s socio-economic situation 

Participants reported the challenges of discussing the benefits and risks of cancer treatment options with lower literacy groups, and tended to provide the basic facts to facilitate understanding. 

Health Literacy and Medication Labels, Instructions, and Regimens

Poor quality and variability of medication labeling have been cited as key contributors to medication misuse. Evidence suggests that health literacy plays a significant role in determining how well patients interpret medication labels and take nonprescription and prescription drugs safely and appropriately.  Recent research aimed at improving medication labeling is described below.

Medication Labels

A study published in 2013 finds a patient-centered label was better at preventing participants from exceeding the maximum dose in 24 hours, compared to a standard label. The patient-centered label did not significantly reduce other dosing errors such as taking more than two pills at a time and waiting fewer than four hours between doses.

A study investigating how parents use active ingredient information found many parents, especially those with low health literacy, do not use active ingredient information as part of decision-making related to administering multiple medications.  Overlapping active ingredients across multiple medications put children at risk for overdose.

A 2012 review of 200 top-selling pediatric oral liquid nonprescription medications found that labeling was often variable and in a format that may impair parent understanding of key medication information, including active ingredient information and dosing instructions.  Although most products listed active ingredients on the Drug Facts panel, 18.5% did not list active ingredients on the principal display panel.  Most products included directions in chart form, while few products expressed dosing instructions in pictographic form. 

In a 2011 study, less than 50% of focus group participants reported routinely examining product label information.  Only 31% were aware that acetaminophen is in Tylenol.  Participants achieved consensus on an icon to identify products that contain acetaminophen, a written statement warning of potential liver damage, and indicated a preference for an icon and wording for maximum daily dose.

Medication Instructions

Medication instructions are often the most tangible, frequently used source of information for patients on proper medication use.  However, they are often vague and unnecessarily complex.  Several studies explore how to improve patients’ comprehension of safe and appropriate medication use.

Medication guides were assessed by Wolf et al 2012 to determine their effectiveness in adequately informing patients on safe use.  Current medication guides were found to be of little value to patients, as they are too complex and difficult to understand especially for individuals with limited literacy.  In a follow-up study, the format and layout of three typical medication guides were modified to promote information accessibility.  Comprehension was significantly greater for all three prototypes compared with the current standard, and the guide modified according to health literacy best practices consistently demonstrated the highest scores, and reduced the effects of age and literacy disparities.

Patient preferences for how best to display patient medication information (PMI) were assessed in a study published in 2014. Similar to the Food and Drug Administration’s medication guides, PMI handouts are intended to help all consumers understand key information about their prescription medicine. Participants in one-on-one interviews noted their preference for new PMI handouts over existing medication guides or consumer medication information.  Although many preferences varied by age, education, and health status, most preferred to see drug information in a chunked format that is printed in a sans serif font, such as Arial. 

Patient opinions, preferences and comprehension of standard and improved medication instructions were assessed in a 2013 study.  Patients agreed on the need for simpler terminology and specificity in instructions.  Discussions addressed optimal ways of presenting numerical information, and indication and duration of use information to promote comprehension and safe use. 

In a study published in 2012, limited English proficient (LEP) patients receiving prescription medication instructions in their native language demonstrated significantly greater prescription understanding in comparison to those receiving standard instructions.  In most cases, instruction type was the sole, independent predictor of greater prescription understanding and demonstrated ability to correctly dose multiple prescriptions in multivariate models controlling for relevant covariates. 

Results from a study published in 2011 show the benefit of including pictographic dosing diagrams as part of written medication instructions for infant acetaminophen.  Parents receiving text-plus-pictogram instructions had higher dosing accuracy than parents receiving standard text-only instructions.  These differences were observed among parents with low health literacy, but not for parents with adequate health literacy.

Medication Regimens

Greater regimen complexity may lead to poorer adherence, which in turn will lead to worse health outcomes.  How patients manage their medication regimens, and the role health literacy plays, are explored in the studies described below.

Lenahan et al 2013 investigated drug regimen familiarity among a cohort of patients with hypertension. Specifically, the authors determined the prevalence of patients’ knowledge of their prescribed drug names and dosages compared to those who relied only on physical characteristics such as pill size, shape and color.  Patients dependent on the visual identification of their medicine reported worse adherence, lower rates of blood pressure control and greater risk of hospitalization.

A study published in 2013 explores the relationship between functional health literacy, medication-taking self-efficacy, and adherence to HIV/AIDS antiretroviral therapy.  Functional health literacy was not significantly related to either medication adherence or self-efficacy beliefs.  The authors suggest their measurement strategy as a possible explanation for this unexpected finding. 

Wolf et al 2011 investigate how well patients manage complex medication regimens that require them to consolidate dosing schedules throughout the day.  The finding that many patients, especially those with limited literacy, do not consolidate regimens efficiently supports the Institute of Medicine’s proposal of a universal medication schedule to standardize prescription practices to improve medication adherence.

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Science Bites

Use pictures to improve health communication

Pictures that are closely linked to written or spoken text and have minimal distracting details can be helpful to individuals with low literacy skills. For evidence of how adding pictures to written and spoken language can increase the effectiveness of health education materials see: The role of pictures in improving health communication: A review of research on attention, comprehension, recall, and adherence. (2006)

Make orally delivered health information accessible and actionable

Just as written material can be made more reader-friendly, orally delivered health information can be made more accessible and actionable. For evidence of how the features of language and interactivity contribute to literacy see: Assessing oral literacy demand in genetic counseling dialogue: Preliminary test of a conceptual framework. (2007).

Use headings to help readers scan and find information

Headings can be helpful organizational elements that ease the reading and use of your materials. Remember, people read our materials because they want to understand something about their health, make a decision, and take action. Descriptive headings should clearly communicate the purpose of the material, who it is for, and how to use it. Readers can skim and make quick judgments about what's worth reading.
For evidence of how descriptive headings and simplified print presentations increase comprehension and recall of informed consent information among those with limited literacy skills see: The effect of format modifications and reading comprehension on recall of informed consent information by low-income parents: A comparison of print, video, and computer-based presentations. (2004)

Headings are also very important in webpage layout. See for instruction on how to use descriptive headings throughout a website to help users scan and find information quickly.

Use narrative communication

Public health information is often presented in numbers and statistics. However, the public may be disinterested or confused by scientific data. You can use narratives such as anecdotes, quotations, examples, vignettes, and personal stories to describe subjects your audience is familiar with. Narratives increase the chance your audience will pay attention to and remember information. Studies find narratives can lead to cancer-relevant belief and behavior change (Green, M.C., 2006) and to be more effective than statistical evidence on some patient outcomes (Mazor et al., 2007).

For more information about narratives and health communication see Hinyard, L.J. & Kreuter, M.W. (2007). Using Narrative Communication as a Tool for Health Behavior Change: A Conceptual, Theoretical, and Empirical Overview

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Chunk information to improve audience comprehension and recall

Readers can handle only a limited amount of information at one time. By grouping information into meaningful "chunks" of reasonable size, we can save our audience from experiencing information overload and improve their ability to organize and recall the material. Doak and colleagues suggest that readers with less education and training may not comfortably process more than 5 pieces of information at a time. See Chapter 5 [6.0 MB, 68 pages] from Doak, Doak, & Root, 1996, Teaching Patients with Low Literacy Skills for an example of how to chunk information.

To learn more about this topic see George A. Miller's classic article on recall that established about seven chunks as the brain's limit for holding information in short-term memory.

Explain risk and numbers

Practical, science-based advice on explaining risks and numbers includes using numbers rather than words alone to explain risk, providing absolute risk (10 out of 100), and keeping the denominators and time frames the same when making comparisons. See Communicating Risks and Benefits: An Evidence-based User's Guide from the U.S. Food and Drug Administration for more evidence on when and how to use numbers and explain risks to the public and patients.

Anticipate and assess audiences' emotional reactions to risk information

Every risk communication is processed both cognitively and emotionally….Success in a risk communication must be measured not only by what recipients know but by how they feel.
Zikmund-Fisher, Fagerlin & Ubel, 2010, Risky feelings: Why a 6% risk of cancer does not always feel like 6%, p. S92

Understand how numbers affect comprehension and decisions

Numeracy is related to perceptions of health-related risks and benefits. Participants lower in numeracy tent to overestimate the risk of cancer and other risk, are less able to use risk reduction information (e.g. about screening) to adjust their risk estimates, and may overestimate benefits of certain treatments.
Reyna, Nelson, Han & Dieckmann, 2009, How numeracy influences risk comprehension and medical decision making, p. 957

Design for improved comprehension among limited health literacy populations

The following specific design features seemed to improve comprehension for low-health-literacy populations in one or a few studies: (1) presenting essential information by itself (i.e. (sic) information on hospital death rates without other distracting information, such as information on consumer satisfaction); (2) presenting essential information first (i.e. (sic) information on hospital death rates before information about consumer satisfaction); (3) presenting health plan quality information such that the higher number (rather than the lower number) indicates better quality; (4) using the same denominators to present baseline risk and treatment benefit; (5) adding icon arrays to numerical presentations of treatment benefit; and (6) adding video to verbal narratives.
Berkman, Sheridan, Donahue, Halpern, et al. 2011, Health literacy interventions and outcomes: An updated systematic review, p. ES-7

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