Science Says: Findings You Can Use

CDC is committed to applying and sharing research to improve health literacy. The findings from the following studies may help organizations improve the effectiveness of their communication and programmatic activities for the public.

1. 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)
2. 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).
3. 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 usability.gov for instruction on how to use descriptive headings throughout a website to help users scan and find information quickly.
4. 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
   
   
5. 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 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.
6. 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.
7. 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
8. 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
9. 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.