HLS₁₉-DIGI - a new instrument for measuring digital health literacy: development, validation and associations with determinants and health outcomes in 13 countries

Introduction: Digital health information sources are playing an increasingly prominent role in health promotion, public health and in healthcare systems. Consequently, digital health literacy skills are likewise becoming increasingly important. Methods: Using a concept validation approach, the aim of the study was to validate a digital health literacy measure applied in the European Health Literacy Survey 2019–2021 (HLS₁₉) of the WHO M-POHL Network, analyzing data from 28,057 respondents from 13 European countries. Results: The scale displayed high internal consistency. Confirmatory factor analysis (CFA) strengthened the hypothesized one-factor structure. In most countries, the data displayed acceptable fit to the unidimensional Rasch partial credit model (PCM). Pearson correlation with a measure of general health literacy showed sufficient discriminant validity, and a social gradient was found. Testing for predictive validity showed that the scale score predicts health-related outcomes. Discussion: The study shows that considerable proportions of the general adult populations across countries in Europe have limited DHL skills. The level of DHL has direct potential consequences for some forms of health service utilization, in some countries. Implications of the study include recommendations for improving digital health literacy, promoting organizational health literacy and quality assurance for digital health information and resources.