Measuring health literacy - the Swedish Functional Health Literacy scale.

BACKGROUND: The benefits of health promotion efforts vary due to a complexity of reasons. One possible reason for an absence of effects is the level of functional health literacy among the individuals that participate in the interventions. Thus, valid and reliable instruments that capture these kinds of skills are needed. The aim of this study was to develop a Swedish Functional Health Literacy scale to use in health promotion and health prevention by translating the Japanese Functional Health Literacy scale into Swedish and testing some aspects of its validity and test-retest reliability.
METHODS: The research project comprised six phases including translation and back translation, validity tests of the two first versions of the instrument based on interviews with professionals and representatives for the target group of the instrument, and a test-retest of the first version among target groups.
RESULTS: The items in the first two versions were experienced as unclear, which led to improvements of the next version. The final version of the translated instrument (the Swedish Functional Literacy scale) showed evidence of content validity, and the test-retest confirmed that the instrument had stability over time with a percentage agreement for the items ranging from 63% to 92% (M = 77.2%).
CONCLUSION: The items in the Swedish version of the scale are equivalent to the original Japanese scale in terms of language and contents and cover the major aspects of functional health literacy as it is defined in the literature. The translated instrument shows stability over time, that is, reliability, at least for a part of the Swedish population. More validity tests of the Swedish Functional Health Literacy scale based on a broader population are needed.