[Measuring health literacy: methods and tools for assessing general health literacy in adults]

The measurement of health literacy (HL) began in the 1990s with instruments that focused on a functional understanding of HL. Since then, the understanding of HL and the measurement of HL have evolved. This article reviews two particularly well-validated instruments for measuring comprehensive general health literacy: The Health Literacy Questionnaire (HLQ) and the HLS₁₉-Q12 questionnaire.The HLQ consists of nine scales with a total of 44 items covering different HL aspects of coping with illness. The HLQ has been validated in numerous studies and translated into 47 languages. It has high content and criterion validity and is used, for example, in the WHO European Action Network on Health Literacy for Prevention and Control of Noncommunicable Diseases and in the European Joint Action on Cardiovascular Diseases and Diabetes (JACARDI). The nine scales can be used to create HL profiles of strengths and challenges.The HLS₁₉-Q12 is a short questionnaire to measure general HL and is based on the HLS₁₉-Q47. It consists of 12 items, has been validated in more than 20 countries, and has been translated into more than 30 languages. The HLS₁₉-Q12 also has high content and criterion validity and is used in the Health Literacy Surveys of the WHO Action Network on Measuring Population and Organizational Health Literacy (M-POHL) and the European Joint Action Prevent Non-Communicable Diseases. Based on the 12 items, a total score is calculated that can be categorized into four levels of HL.In order to create a comparable database in the long run, it is recommended that these two instruments be used in studies, evaluations, and monitoring of HL.