Validation of the Swedish version of HLS19-Q12: a measurement for general health literacy.

Health literacy (HL) is a critical determinant of health, as it affects health behavior and outcomes, in addition to equity in health. This study aimed to translate, culturally adapt, and validate the Swedish version of HLS19-Q12 (HLS19-Q12-SE). The HLS19-Q12 is a widely used instrument that consists of 12-items and is often used to assess HL in Europe. A convergent mixed-methods design was applied, including cognitive interviews (n  =  8) and psychometric testing with a survey sample (n  =  374) and test-retest group (n  =  28). The instrument was forward and backwards translated and culturally adapted. Data was analyzed using confirmatory and exploratory factor analysis, correlation testing, and reliability assessments. Cognitive interviews explored the clarity, interpretation, and contextual relevance of the items. Participants found the HLS19-Q12-SE clear and easy to understand, though some reported difficulties with unfamiliar health situations and uncertainty of the term "health information." Based on the interviews, the examples for one of the items were culturally adapted. Psychometric testing showed good feasibility, no floor or ceiling effects on scale level, and moderate positive correlations with other HL instruments, supporting internal and external validity. Structural validity was confirmed, and internal consistency and test-retest reliability were satisfactory. However, ceiling effects were observed at the dichotomous item level, and correlations with self-rated health and social status were low. The HLS19-Q12-SE is a reliable and valid instrument for assessing general HL in Sweden. While psychometric properties were strong overall, future research should address ceiling effects on item level and explore the instrument's performance in more diverse populations.