The purpose of this review is to summarize the relevant literature related to health literacy instruction and to identify existing gaps in the literature. According to Ratzan and Parker (2012), health related decisions and healthcare related outcomes are significantly influenced by an individual’s ability to understand, process and take action on health information. In 2004, the Institute of Medicine made health literacy a national priority because of the very large number of Americans with low health literacy, and because of its impact on the healthcare system, especially those with health disparities (Neilsen-Bohlman, Panzer and Kindig, 2004).
A National action plan to improve health literacy, designed to restructure the ways that health information is disseminated, has set the vision and goals for the future (U.S. Department of Health and Human Services (DHHS), 2010). These goals include the development and dissemination of clear and accurate information, use of evidence based and developmentally appropriate information and encourage new and innovative approaches (DHHS, 2010).
Health Literacy Assessment
The National Assessment of Adult Literacy (NAAL) used health related tasks that measured prose, document and quantitative literacy in clinical, prevention and navigation of the healthcare system domains (Kutner, Greenbery, Jin and Paulsen, 2006). Quantitative literacy scores are lower than prose and document literacy, with 61% of respondents below basic and only 2% proficient (Kutner et al. 2006). While age greater than 65, those that live in poverty, and those of whom English is not their native language had lower scores, a large number of younger, well educated, English speaking individuals have below basic health literacy scores (Kutner, 2006).
Since the NAAL is impractical as a screening tool, and since there is no other goal standard measurement of health literacy, several assessments of print, number and oral health literacy are used in studies involving health literacy, making comparisons among these studies difficult. According to Berkman et. al. (2011) the Rapid Estimate of Adult Literacy in Medicine (REALM) and the Test of Functional Health Literacy in Adults (TOFHLA) are the most commonly used validated assessments of health literacy. The REALM is a test of word recognition, while the TOFHLA measures reading and numeracy, which is the ability to understand and manipulate numbers (Berkman, et al. 2011).
Health Literacy and Health Related Outcomes
Cross sectional studies, prospective observational studies and randomized, controlled trials have been conducted on patients with diabetes and hypertension, heart failure and obesity. The outcomes have included knowledge, self-management skills, an improvement in numbers, hospitalizations and mortality. Numeracy is a key aspect of health literacy as it relates to the understanding of numbers, which are important for the management of weight, blood pressure, and glucose.
In a large, multi-site, prospective study of enrollees in a Medicare managed care plan, conducted from 1997 through 2003, Baker, Wolf, Feinglass, Thompson, Gazmaranian and Huang (2007) found mortality rates to be significantly higher in participants with inadequate health literacy than participants with adequate health literacy. Reading fluency was a more powerful predictor of all-cause mortality and cardiovascular death than years of education (Baker, et al. 2007). In a randomized, controlled trial, Dewalt, Malone, Bryant, Kosnar, Corr, et al. (2006) found that education on self-management skills such as daily weight monitoring, medication management and symptom recognition reduced the risk of hospitalization and death in heart failure patients with low levels of literacy. Huizinga, Beech, Cavanaugh, Elasy and Rothman (2008) found a significant, negative correlation between numeracy and body mass index.
In a randomized trial Jay, Adams, Herring, Gillespie, Ark, et al. (2009) found that brief multimedia interventions, including a video and food label pocket cards could improve food label comprehension, but actual dietary changes or health related outcomes were not assessed. In a cross-sectional study of primary care patients, Rothman, Housam, Weiss, Davis, Gregory, et al. (2006) found that poor food label understanding was correlated with low literacy and numeracy skills, but even patients with high literacy skills had trouble interpreting labels.
In a prospective, observational trial of patients with diabetes, (Kim,Love, Quistberg and Shea, 2004) found that diabetes education was effective in improving self- management skills, knowledge of their diabetes and control of their blood glucose. Patients with low literacy reported better adherence to diet, self-glucose management and foot care (Kim, et al. 2004).
In 2012 an estimated 76.4 million Americans have hypertension and only 64% of those that are being treated are achieving their blood pressure goal (Roger, et al, 2012). Hypertension is associated with an increased risk of heart disease, stroke, heart failure and kidney failure resulting in a cost of $50.6 billion (Roger, et al. 2012). According to Appel, et al. (2006) there is a substantial body of knowledge demonstrating the effects of self-management skills, including dietary and physical activity interventions, on hypertension. Maintaining or achieving a desirable body weight by balancing physical activity and caloric intake, reducing sodium intake, consuming more fruits and vegetables, reducing saturated fat and cholesterol, increasing potassium intake, and consuming alcohol only in moderation are effective strategies for achieving blood pressure control (Appel, et al. 2006).
In a cross sectional study of patients with hypertension and diabetes, Williams, Baker, Parker and Nurss, (1998) found that patients with lower health literacy scores were significantly less likely to identify a normal blood pressure or blood glucose reading than patients with high health literacy scores, which poses a significant barrier to teaching self-management skills.
A key aspect of health literacy is being able to navigate the healthcare system. In a cross-sectional study of 1224 hypertensive patients, Powers, Olden, Oddone, Thorpe and Bosworth (2008) found that the challenges of navigating the healthcare system is an interactive effect in the relationship between health literacy and systolic blood pressure, but not diastolic blood pressure. Pandit, Tang, Bailey, Davis, and Bocchini, et al. (2009) found that low education and limited literacy were significant predictors of blood pressure control and that literacy was a mediator in the relationship between education and knowledge. Persell, Bailey, Tang, Davis and Wolf (2010) found that medications discrepancies and incorrect medication reconciliation are very common in hypertensive patients, further complicating this key step in the treatment of these patients. In a randomized trial of hypertensive patients, Bosworth, Olsen, Grubber, Neary, and Orr, et al.(2009) found that blood pressure monitoring and tailored telephone intervention resulted in significantly better blood pressure control compared to a usual care group.
Health Literacy Instruction
A gap in the literature is whether the interventions used in health literacy studies actually result in an increase in health literacy. Interventions that simplify the message by using plain language may improve outcomes by modifying behavior without increasing knowledge or literacy. In an American Heart Association Scientific Statement, Artinian, et al. (2011) reviewed behavioral interventions designed to improve cardiovascular outcomes and determined that the most effective strategies include goal setting, self-monitoring, frequent and prolonged contact, feedback and reinforcement, incentives, modeling, problem solving, relapse prevention and motivational interviewing.
Paasche-Orlow, and Wolf (2007) developed a causal model, linking health literacy to health outcomes. Three interrelated components of this model are access and utilization of healthcare, which have patients and system factors; provider-patients interaction including knowledge and communication; and self-care factors, including motivation, self-efficacy, knowledge and extrinsic factors, such as education and the media (Paasche-Orlow and Wolf, 2007). To test this model, Osborne, Paasche-Orlow, Bailey and Wolf (2011) investigated the mechanisms linking health literacy to behavior and health status in a cross sectional study of hypertensive patients, and determined that health education interventions should be literacy sensitive and focus on knowledge and efficacy. Health literacy was directly related to knowledge, self-efficacy was related to self-management interventions, such as physical activity, and these behaviors were related to health status (Osborne , 2011).
According to Lesgold and Welch-Ross (2012) there is a surprising lack of rigorous research on effective approaches to adult literacy instruction and the majority of this research is based on the K-12 population and there has been virtually no research on health literacy for adults of whom English is their second language (Lesgold and Welch-Ross, 2012). In fact, the majority of research in the area of adult learning is with college students and professional development, not patient education (Lesgold and Welch-Ross, 2012). According to Grossman, Powers and McGinnis (2011) the growing digital infrastructure provides opportunities for communication and learning that have not been available previously. These opportunities can engage and empower patients, but must also be available and usable to individuals with low levels of health literacy (Grossman, 2011). The Agency for Healthcare Research and Quality has developed a toolkit for improving healthcare communications, including spoken word, written communications, self-management and empowerment and supportive systems (Dewalt, Callahan, Hawk, Broucksou, and Hink, 2010). While this toolkit provides resources for providing simplified, accurate information for patients using plain and direct language, it does not provide tools or teaching and learning strategies for increasing health literacy.
In an annual review of public health, Koo and Miner (2010) proposed the use of a multi-tiered model for developing knowledge and skills in the public health workforce. This strategy could be applied to health literacy instruction of patients and the community. Another example of adult education is medical professionals. Beckman and Lee (2009) propose applying Bloom’s taxonomy, which is a classic educational model, for the teaching medical students. The Bloom model includes knowledge, comprehension, application, analysis, synthesis and evaluation (Beckman, 2009). While Koo and Miner (2010) and Beckman and Lee (2009) are using an educational for public health and medical professionals, this strategy could be used to increase the level of health literacy in the United States.
Summary of the Gaps in the literature
It is unclear from the research whether health literacy can be improved or that an improvement in health literacy will result in improved outcomes. Also, the majority of research on literacy instruction is on subjects kindergarten through grade 12, not on adults. Finally, while simplification of the message may be an effective strategy for basic self-management skills, such as daily weight monitoring or taking medications, but there it is unclear how effective this strategy is for more complicated activities, such as making dietary changes. It is also unclear whether individuals with adequate or above average literacy. Focusing on simplifying the message that they already understand is unlikely to be a benefit.
Appel, L.J., Brands, M.W., Daniels, S.R., Karanja,N., Elmer, P.J., and Sacks, F.M. (2006). Dietary approaches to prevent and treat hypertension: A scientific statement from the American Heart Association. Hypertension, 47, 296-308.
Artinian, N.T., Fletcher, G.F., Mozaffarian, D., Kris-etherton, P., Van Horn, L., Lichtenstein, A.H., Kumanyika, S., Kraus, W.E., Fleg, J.L., Redecker, N.S., Meinenger, J.C., Banks, J.A., Stuart-Shor, E.M., Fletcher, B.J., Miller, T.D., Hughes, S., Braun, L.T., Kopin, L.A., Berra, K., Hayman, L.L., Ewing, L.J., Ades, P.A., Durstine, J.L., Houston-Miller, N., Burke, L.E., on behalf of the American Heart Association Prevention Committee of the Council on Cardiovascular Nursing, Circulation, 122,406-441.
Beckman, T.J., and Lee, M.C. (2009). Proposal for a collaborative approach to clinical teaching. Mayo Clinic Proceedings, 84, 339-344.
Dewalt, D.A., Malone, R.M., Bryant, M.E., Kosnar, M.C., Corr, K.E., Rothman, R.L., Sueta, C.A., and Pignone, M.P. (2006). A heart failure self-management program for patients of all literacy levels: A randomized, controlled trial. BMC Health Services Research, 6,30. doi:10.1186/1472-6963-6-30.
Dewalt, D.A., Callahan, L.F., Hawk, V. V.H., Broucksou, K.A., and Hink, A. (2010). Health literacy universal precautions toolkit. Rockville, MA., Agency for Healthcare Research and Quality, Retrieved from: http://www.ahrq.gov/qual/literacy/healthliteracytoolkit.pdf.
Baker, D.W., Wolf, M.S., Feinglass, J., Thompson, J.A., Gazmarian, J.A., and Huang, J. (2007). Health literacy and mortality among elderly persons. Archives of Internal Medicine. 167, 1503-1509.
Baker, D.W. (2006). The meaning and measure of health literacy. Journal General Internal Medicine. 21(8). 878-883.
Berkman, N.D., Sheridan, S.L., Donohue, K.E., Halpern, D.J., Viera, A., Crotty, K., Holland, A., Brausure, M., Lohr., K.N., Harden, E., Tant, E., Wallace, I., and Viswanathan, M. (2011). Health literacy interventions and outcomes: An updated systematic review. Rockville, MD. Agency for Healthcare Research and Quality.
Bosworth, H.B., Olsen, M.K., Grubber, J.M., Neary, A.M., Orr, M.M., Powers, B.J., Adams, M.B., Svetkey, L.P., Reed, S.D., Li, Y., Dolor, R.J., and Oddone, E.Z. (2009) Two self-management interventions to improve hypertension control: A randomized trial. Annals of Internal Medicine, 151, 687-695.
Grossman, C., Powers, B., and McGinnis, J.M. (eds) (2011). Digital infrastructure for the learning health system: The foundation for continuous improvement in health and health care. Washington, D.C. National Academies Press.
Huizinga, M.M., Beech, B.M., Cavanaugh, K.L., Elasy, T.A., and Rothman, R.L. (2008). Low numeracy skills are associated with higher BMI. Obesity. 16, 1966-1968.
Jay, M., Adams, J., Herring, S.J., Gillespie, C., Ark, T., Feldman, H., Jones,V., Zabar, S., Stevens, D., and Kalet, A. (2009). A randomized trial of brief multimedia intervention to improve comprehension of food labels. Preventive Medicine, 48, 25-31.
Kim, S., Love, F.L., Quistberg, D.A., and Shea, J.A. (2004). Association of health literacy with self-management behavior in patients with diabetes. Diabetes Care. 27, 2980-2982.
Koo, D. and Miner K. (2010). Outcome-based workforce development and education in public health. Annual review of public health. 31, 253-269.
Kutner, M., Greenberg, E., Jin,Y., and Paulsen, C. (2006). The Health Literacy of America’s Adults: Results From the 2003 National Assessment of Adult Literacy (NCES 2006–483).U.S.Department of Education. Washington, DC: National Center for Education Statistics.
Lesgold, A.M., and Welch-Ross, M. (2012). Improving adult literacy instruction: Options for practice and research. National Academies Press, Washington, D.C.
National Research Council (2012). Improving Adult Literacy Instruction: Options for Practice and Research. Washington, D.C. National Academy of Sciences. Retrieved from: http://www.nap.edu/catalog.php?record_id=13242
Nielsen-Bohlman, L. Panzer, A.M., and Kindig, D.A. Editors, Committee on Health Literacy Institute of Medicine. (2004). Health Literacy: A prescription to end confusion. Washington, D.C. National Academies Press. Retrieved from: http://www.nap.edu/catalog/10883.html.
Osborne, C.Y., Paasche, M.K., Bailey, S.C., and Wolf, M.S. (2011). The mechanisms linking health literacy to behavior and health status. American Journal of Health Behavior, 35, 118-128.
Paasche-Orlow, M.K., and Wolf, M.S. The causal pathways linking health literacy to health outcomes. American Journal of Health Behavior, 31, S19-s26.
Pandit, A.U., Tang, J.W., Bailey, S.C., Davis, T.C., Bocchini, M.V., Persell, S.D., Federman, A.D., and Wolf. M.S. (2009). Education, literacy and health: Mediating effects on hypertension knowledge and control. Patient Education and Counseling, 75, 381-385.
Persell, S.D., Bailey, S.C., Tang, J., Davis, T.C., and Wolf, M.S. (2010). Medication reconciliation and hypertension control. American Journal of Medicine, 182, e9-e15.
Ratzan, R. and Parker, S. (2012). Health literacy: A second decade of distinction for Americans. Journal of Health Communication: International Perspectives. 15. 20-33.
Roger, VL., Go, A.S., Lloyd-Jones, D.M., Benjamin, E.J., Berry, J.D., Borden, W.B., Bravata, D.M., Dai, S., Ford, E.S., Fox, C.S., Fullerton, H.J., Gillespie, C., Hailpern, S.M., Heit, J.A., Howard, V.J., Kissela, B.M., Kittner, S.J., Lackland, D.T., Lichtman, J.H., Lisabeth, L.D., Makuc, D.M., Marcus, G.M., Marelli, A., Matchar, D.B., Moy, C.S., Mozaffarian, D., Mussolino, M.E., Nichol, G., Paynter, N.P., Soliman, E.Z., Sorlie, P.D., Sotoodehnia, N., Turan, T.N., Viriani, S.S., Wong, N.D., Woo, D., Turner, M.B., on behalf of the American Heart Association Statistics Committee and Stroke Statistics Committee (2012. Heart disease and stroke statistics – 2012 update: A report from the American Heart Association. Circulation, 125, e2-e220.
Rothman, R.L., Housam, R., Weiss, H., Davis, D., Gregory, R., Gebretsadik, T., Shintaini, A., and Elasy, T.A. (2006). Patient understanding of food labels: The role of literacy and numeracy. American Journal of Preventive Medicine, 31, 391-398.
U.S. Department of Health and Human Services, Office of Disease Prevention and Health Promotion. (2010). National Action Plan to Improve Health Literacy. Washington, DC.
Williams, M.V., Baker,, D.W., Parker, R.M., and Nurss, J.R. (1998). Relationship of functional health literacy to patient’s knowledge of their chronic disease. Archives of Internal Medicine. 158, 166-172.