The evolving concept ofHealth literacy: New directions for health literacy studies

This article aimed to provide a descriptive review of the psychometric properties and conceptual dimensions of published health literacy measurement tools. PsycINFO and PubMed search from 1999 through 2013, review of the grey literature, and an environmental scan was conducted to identify health literacy measurement tools. For each tool, we evaluated the conceptual dimensions assessed, test parameters, and psychometric properties. Of the 51 tools identified, 26 measured general health literacy, and 15 were disease or content specific, and 10 aimed at specific populations. Most tools are performance based, require in-person administration, and are exclusively available in a pencil and paper testing mode. The tools assess 0 (proxy measure) to 9 of the 11 defined dimensions of health literacy. Reported administration times vary, from less than 1 to 60 minutes. Validation procedures for most of the tools are limited by inadequate power to ensure reliability across subgroups (i.e., race, age, ethnicity, and gender). The health literacy measurement tools currently available generally represent a narrow set of conceptual dimensions with limited modes of administration. Most of the tools lack information on key psychometric properties. Significant work is needed to establish important aspects of the construct, convergent, and predictive validity for many tools. As researchers develop new measures, inclusion of a full range of conceptual dimensions of health literacy, more representative sampling for testing, and additional modes of administration will allow a more refined and flexible approach to research in this field.

Insights for action in the relatively new field of health literacy have been constrained by the emphasis on the literacy skills of the individuals. Early studies into the relationship between literacy and health outcomes were not appropriately balanced with examinations of individuals' skills and health system demands. Most studies focused on the measures of patients' reading skills without due attention to the health tasks undertaken, the health materials used, or the skills of providers with whom patients were interacting. Furthermore, public health is founded on the epidemiologic notion of the reciprocal relationship between individuals and environments. Early studies in health literacy did not attend to context-the physical and social environment of health-care settings. New initiatives in health literacy must bring attention to the demands and expectations of health systems and to the proficiencies of the various health professionals who prepare documents and information for the public and who interact with communities and patients.