Health literacy, “the degree to which individuals have the capacity to obtain, process, and understand basic health information and services needed to make appropriate health decisions” (Ratzan and Parker, 2000) is being increasingly recognized as important to health and health outcomes (Berkman et al., 2004). Although research on health literacy has grown tremendously in the past decade, both in terms of assessing the level of health literacy of individuals and examining the relationship of health literacy to various health outcomes, a concern is that there is no widely agreed-on framework for health literacy as a determinant of health outcomes. Furthermore, existing measures do not adequately capture the data that are necessary to understand how health literacy works to affect outcomes (Pleasant, 2009) and what can be done to improve health literacy.
The only national health literacy assessment tool is the National Assessment of Adult Literacy (NAAL) supplement conducted by the Department of Education in 2003. The NAAL identifies four levels of health literacy: below basic, basic, intermediate, and proficient.
Several other instruments are used for assessing the health literacy of individuals, including the frequently used Rapid Estimate of Adult Literacy in Medicine (REALM) and the Test of Functional Health Literacy in Adults (TOFHLA). One problem with these instruments, however, is that they largely measure reading ability or print literacy. This makes it difficult to differentiate between health literacy and basic literacy. Another difficulty is assessing health literacy of those with limited English pro-
ficiency. Several of the health literacy assessment tools discussed in the following report attempt to address this difficulty.
Population-based assessments of health literacy focus on the health literacy of populations rather than individuals. Two of these approaches, the Demographic Assessment of Health Literacy (DAHL) and a geomapping approach, are discussed in Chapter 4. The DAHL imputes limited health literacy from sociodemographic indicators and estimates the association of imputed limited health literacy with indicators of health status. The geomapping approach uses Census data and the NAAL data to map mean health literacy by Public Use Microdata Area.
However, most currently available instruments focus on assessing an individual’s health literacy, yet health literacy is broader than an individual’s skills and abilities. Health literacy occurs in the context of the health care system, and it is increasingly recognized that measures of health literacy must assess not only patients’ skills and abilities, but also the demands and complexities of the health care systems with which patients interact. For example, measures are needed to determine how well the system has been organized so that it can be navigated by individuals with different levels of health literacy and how well health organizations are doing at making health information understandable and actionable.
The Institute of Medicine Roundtable on Health Literacy serves to educate the public, press, and policy makers regarding issues of health literacy. To examine what is known about measures of health literacy, the Roundtable convened a planning committee (see Appendix A) to develop a workshop agenda that would address the following issues:
The current status of measures of health literacy, including those used in the health care setting;
Possible surrogate measures that might be used to assess health literacy; and
Ways in which health literacy measures can be used to assess patient-centered approaches to care.
The following pages summarize the workshop presentations and discussions. Chapter 2 presents an overview of the field of health literacy measurement, describing current measurement tools and their strengths and weaknesses, measurement needs, and proposed principles for developing health literacy measures. In Chapter 3 several new approaches to assessing health literacy are presented, including new measures of written and oral health literacy, a bilingual assessment of health literacy, self-report measures of health literacy, a functional approach to assessing health literacy, and an approach to measuring whether people understand
what they hear. Chapter 4 explores two population-based approaches to assessing health literacy—the DAHL and geographic coding of health literacy. Chapter 5 explores health system responses to health literacy, including development of two new health literacy supplements to the Consumer Assessment of Healthcare Providers and Systems (CAHPS). Chapter 6 summarizes the presentation and discussion, which focused on reflections of the entire workshop as well as a vision for the future.