Measuring health literacy : Evaluating psychometric properties of the HLS-EU-Q47 and the FCCHL, suggesting instrument refinements and exploring health literacy in people with type 2 diabetes and in the general Norwegian population

Sammanfattning: Aim: The overall aim was to measure health literacy (HL) in people with type 2 diabetes (T2DM) and in the general Norwegian population.Methods: Sampling 388 people with T2DM (papers I, II and IV) and 900 individuals (III) in the general Norwegian population a cross-sectional design was applied. Rasch modelling and confirmatory factor analysis were used to evaluate the psychometric properties of the 47 items HLS-EU-Q47 questionnaire (I and III) and the 14 items FCCHL scale (II), and to develop and evaluate a 12 item short version, HLS-N-Q12 (III and IV), based on HLS-EU-Q47. Descriptive and inferential statistics were used to describe HL and to investigate associations between HL and various independent variables.Main results: The HLS-EU-Q47 displayed psychometric shortcomings in both populations (I and III). A 12-dimensional model described the data best. Several items showed misfit to the Rasch model and statistical dependence. Aiming at meeting the requirements of objective measurement, the HLS-N-Q12 was suggested (III and IV). Evaluating the FCCHL in people with T2DM, the data fitted a three-dimensional model best (II). Several items showed misfit to the Rasch model and unordered response categories. However, a three-dimensional 12-item version of the FCCHL had acceptable psychometric properties. Education, good general health and empowerment were positively associated with HL in people with T2DM, explaining about 17% of the total variance in HL (IV).Conclusions: In both populations, the HLS-N-Q12 displayed solid psychometric properties and might therefore be used as a measure of HL for both clinical and research purposes. Nurses and other health professionals must be aware that HL influence individuals’ proficiency in managing their health. Hence, nurses and other health professionals should map HL in individuals and adapt health information accordingly.