Health literacy is of concern to everyone involved in health promotion and protection, disease prevention and early screening, health care and maintenance, and policy making. Health literacy skills are needed for dialogue and discussion, reading health information, interpreting charts, making decisions about participating in research studies, using medical tools for personal or familial health care—such as a peak flow meter or thermometer—calculating timing or dosage of medicine, or voting on health or environmental issues. This report makes use of the operational definition of health literacy developed for the National Library of Medicine and used by Healthy People 2010: