INTRODUCTION AND OVERVIEW
Literacy, the foundation of education, sheds light on the well-established pathway between education and health outcomes. However, literacy had not been a consideration in most health studies, programs, or practices in industrialized nations until recently because literacy concerns were generally associated with developing nations. In the early 1990s, findings from international surveys of adult literacy conducted in 22 industrialized nations indicated that literacy is problematic in these technologically sophisticated nations with consequences for the economy, daily life, and civic engagement.1 These findings inspired health researchers to examine the influence of literacy on health outcomes. Within the first decade of research, links between the literacy skills of patients and their health outcomes were firmly established.2 As a result, health literacy emerged as a new variable for health studies—offering insight into health outcomes and health disparities and generating interest among health researchers, practitioners, and policy makers.
Over the past two decades, the definition of health literacy has evolved, new component factors have emerged, and new measures have been developed. Studies indicate that health literacy considerations can improve strategic efforts in clinical care by improving dialogue and discussion between and among health professionals and between health professionals and patients with concrete implications for health outcomes. Health literacy in the public health arena is informing programs and evaluation studies in health communication, health promotion, disease prevention, care management, environmental health, and preparedness. Examination of institutional and system level characteristics that support or impede health literacy are informing health policy initiatives in many countries.
Rigorous surveys of adult literacy skills were initiated in the 1990s among member countries of the Organization for Economic Cooperation and Development (OECD) to examine the population’s readiness to participate in sophisticated technological and complex social and economic environments. Findings from the first wave of international adult literacy surveys1,3 as well as those from subsequent surveys4,5 indicated that large percentages of the population of most industrialized nations have limited literacy and math skills. This means that a significant proportion of adults have difficulty using commonly available materials to accomplish everyday tasks with accuracy and consistency. These everyday tasks relate to activities undertaken for civic engagement, participation in the workforce, family, health, economics, and community as well as for problem solving and use of technology. Assumptions that universal schooling yields high or even adequate population skill levels were shown to be faulty. Literacy was indeed found to be a significant issue in most industrialized nations. This realization spurred interest among health researchers examining a wide variety of health outcomes.
Population-based measures of health literacy further strengthened interest from the health sector. The Health and Adult Literacy Survey (HALS) and the National Assessment of Adult Literacy (NAAL) focused on health-related items and tasks linked to the adult literacy surveys. Analyses indicated that about half of U.S. adults, including both those without a high ...