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Definition of terms

Health Literacy—Health literacy is defined as the degree to which individuals can obtain, process, and understand basic health information and services needed to make appropriate decisions regarding their health (Health People—2010).

NAAL - According to the most recent National Assessment of Adult Literacy (NAAL), a national survey conducted by the U.S. Department of Education & National Center for Education Statistics in 2003, over 90 million Americans have trouble understanding fairly basic health information. This not only includes interpreting print information but incorporates tasks such as following medication instructions, identifying signs and symptoms of illness, and engaging in self-care behaviors. The report identifies four separate health literacy categories with examples of a health task relevant to each literacy level and the proportion of the population at each level as follows (Source—NAAL Report 2003):

  • Below Basic: Being able to identify and correctly circle the date of a medical appointment on a hospital appointment slip. 14% of the population was in this category.
  • Basic: Can give two reasons a person with no symptoms of a specific disease should be tested for that disease based on information contained in a clearly written pamphlet. 22% of the population was in this category.
  • Intermediate: Ability to accurately interpret and understand a prescription drug label. 53% of the population was in this category.
  • Proficient: Can calculate an employee’s share of health insurance costs for a year using a table that shows how the employee’s monthly cost varies depending on income and family size. 12% of the population was in this category.


It is clear from this report that low health literacy is present across all races, ethnicities, and insurance types; however, two additional and interesting findings from the report were the disproportionate levels of low health literacy among ethnic/racial minorities and those with no or limited sources of insurance. Specifically the NAAL found that 28% of Whites had basic or below basic health literacy skills compared to 58% of Blacks and 66% of Hispanics. Ethnic minorities as well as the economically disadvantaged, rural populations, women, elderly, and children have all been identified by the Agency for Healthcare Research and Quality as research “priority groups” in that they often experience a disproportionate burden of disease and disparities in healthcare access and quality. Interestingly, we are in fact seeing a growing amount of research activity involving the potential contribution of low health literacy to healthcare disparities both in the U.S. and internationally.

Percentage of adults in each health literacy level, by race/ethnicity:2003 Percentage of adults in each health literacy level, by type of health insurance coverage:2003 
Source: Kutner MA, United States. Dept. of Education., National Center for Education Statistics.: The health literacy of America's adults : results from the 2003 National Assessment of Adult Literacy. Washington, DC., United States Department of Education ; National Center for Education Statistics, 2006


Clear Health Communication - As noted above, the definition of health literacy emphasizes individual skills and abilities, whereasClear Health Communication refers to effective communication within the broader and often complex healthcare environment that individuals are required to navigate. Here, the individual health consumer is joined by the healthcare professional, clinic or hospital staff, insurance provider, managed care organization, and others, all of whom play important roles in ensuring that the individual patient receives health information that is both clear and actionable. For researchers and policy-makers, emphasizing the importance of clear health communication should be our goal as we seek to describe, understand, and intervene upon the current healthcare environment.


Define the scope and impact of health literacy deficits

In terms of health outcomes: A growing body of evidence supports the association between deficits in health literacy and various health related outcomes such as:

  • Lower reported health status
  • Greater mortality
  • Less disease-specific knowledge and ability to recognize common signs and symptoms of illness
  • Greater utilization of hospital services
  • Less self-confidence and skills needed for self-care and chronic disease management
  • Lower receipt of important screening procedures (e.g. colonoscopy) and vaccinations
  • Poorer understanding of medication and food labels

A comprehensive review lead by the Agency for Healthcare Research and Quality in 2011 sought to summarize the current science supporting these associations, and they found that for many outcomes the quality/strength of the literature was limited in many areas due to a number of smaller, observational study designs. For example, the collective evidence was limited among studies that identified worse diabetes self-management among low health literate patients. Similar results held true for access to care, asthma severity and control, and certain screening practices (e.g. colon cancer, STD). Moderate evidence does support the association between low health literacy and increased ER visits, hospitalizations, lower influenza vaccination rates, decreased ability to interpret health messages, less mammography screening, worse medication adherence, and higher mortality among the elderly. Dewalt and Hink similarly reviewed the impact of health literacy on child health outcomes and found that children with low literacy had worse health behaviors and parents with low literacy had less health knowledge and behaviors that are advantageous for their children’s health.

In terms of health costs: It is challenging to assign a precise dollar amount to the overall impact of low health literacy on healthcare costs. This is in part due to significant heterogeneity in how health literacy is measured as well as a relative lack of economic evaluations. A recent and rigorous systematic review of health literacy associated costs conducted by Eichler et al. identified 10 studies that addressed this issue. These studies suggested that the additional costs of limited health literacy on the health system level range from 3% to 5% of the total health care costs per year. Using estimates from the National Health Expenditure Report in 2009 would therefore equate the overall economic burden of low health literacy to around $75-125 billion dollars annually. Future research will define this more precisely. Research is also needed to better describe the cost-effectiveness of health literacy targeted interventions.


Materials and Sentinel Reports

Update of Selected Research Bibliography (2007—present):

AuthorTitleJournalCitationBrief synopsisCategoryYear
Berkman ND, et al.Low health literacy and health outcomes: an updated systematic reviewAnn Intern Med2011 Jul 19;155(2):97-107HL is associated with differential use of certain health care services, poor medication and health message comprehension, and among the elderly, poorer overall health status and higher mortality. There is emerging evidence that low HL may explain racial disparitiesHL and outcomes/systematic review2011
Clark BUsing law to fight a silent epidemic: the role of health literacy in health care acces, quality, & costAnn Health Law2011 Summer;20(2):253-327Discussion of the role of law and policy in bringing about necessary health literacy reform and its potential impact on healthcare quality and cost.HL and policy2011
Coleman CTeaching health care professionals about health literacy: A review of the literatureNurs Outlook2011 Apr;59(2):70-78Review of the literature on teaching health liteacy principles to health professionals and presents a menu of teaching options for health professions educators.HL and education/review2011
DeWalt DA, et al.Developing and testing the health literacy universal precautions toolkitNurs Outlook2011 Apr;59(2):85-94Review of the development of the Health Literacy Universal Precautions Toolkit (HLUP) geared toward helping practices restructure their delivery of care.HL tools2011
Goldberg JP, Sliwa SACommunicating actionable nutrition messages: challenges and oportunitiesProc Nutr Soc2011 Feb;70(1):26-37Review of the challenges of communicating accurate and actionable health behavior information given the evolution of nutrition sciences.HL and communication2011
Herdon JB, et al.Health Literacy and Emergency Department Outcomes: A Systematic ReviewAnn Emerg Med2011 Apr;57(4):334-345Compilation of articles published 1980-2010 reporting a health literacy measure in ED patients, readability of ED materials, or the association between health literacy and ED-related outcomes.HL and outcomes/systematic review2011
Hendren S, et al.Patients' barriers to receipt of cancer care, and factors associated with needing more assistance from a patient navigatorJ Natl Med Assoc2011 Aug;103(8):701-710Secondary analysis of a RCT of a patient navigation intervention in which newly diagnosed breast and colorectal cancer patients were assisnged to a community health worker who collected information of barriers to care.HL interventions2011
Jordan JE, et al.Critical appraisal of health literacy indices revealed variable underlying constructs, narrow content and psychometric weaknessesJ Clin Epidemiol2011 Apr;64(4):366-79Critical appraisal of existing health literacy measurement tools developed from 1990-2008. 19 instruments identified; Most rely on testing of individual abiliites, self-report, or use population-based proxy measures.HL and measurement2011
Lora CM, et al.Progression of CKD in Hispanics: Potential Roles of Health Literacy, Acculturation, and Social SupportAm J Kidney Dis2011 Aug;58(2):282-290Examination of the potential role of patient-centered characteristics in the disparate development and progression of chronic kidney disease in Hispanics.HL and disparities2011
Marvanova M, et al.Health literacy and medication understanding among hospitalized adultsJ Hosp Med2011 Nov;6(9):488-93Evaluated the association between health literacy and pre-admission understanding of medications among hospitalized adults.HL and outcomes2011
Osborn CY, et al.Health literacy explains racial disparities in diabetes medication adherenceJ Health Commun2011;16 Suppl 3:268-78This study explored whether health literacy and/or numeracy were related to diabtes medication adherence and whether either factor explained racial differences in adherence.HL and disparities2011
Sarkar U, et al.Validation of self-reported health literacy questions among diverse English and Spanish-speaking populationsJ Gen Intern Med2011 Mar;26(3):265-71Validation of simple self-reported health liteacy screening questions for distinguishing patients with adequate and inadequate health literacy.HL and measurement2011
Sheridan SL, et al.Interventions for individuals with low health literacy: a systematic reviewJ Health Commun2011; 16 Suppl 3:30-54Review of the literatrue on interventions designed to mitigate the effects of low health literacyHL interventions2011
Welch VL, et al.Time, costs, and clinical utilization of screening for health liteacy: a case study using the Newest Vital Sign (NVS) instrumentJ Am Board Fam Med2011 May-Jun;24(3):281-9Cost and utility analysis of using the NVS in a primary care settingHL measurement2011
Zamora H, Clingerman EMHealth literacy among older adults: a systematic literature reviewJ Gerontol Nurs2011 Oct;37(10):41-51Review of published literature on the prevalence of health literacy deficits in adults 65 and olderHL and disparities2011


Important reports for researchers and policy stakeholders