Associations between digital health literacy and health system navigating abilities among Norwegian adolescents: validating the HLS₁₉-DIGI scale using Rasch modeling

Background: Despite increasing global attention to health literacy and adolescents’ digital health information seeking, no unidimensional instruments measuring digital health literacy (DHL) in adolescents have reportedly been validated using Rasch modeling. Moreover, the evidence of adolescents’ abilities to navigate the health system (NAV-HL) in light of their DHL proficiency is still scarce. Therefore, our study aims to evaluate the psychometric properties of a DHL instrument (HLS₁₉-DIGI scale) in order to investigate DHL in adolescents and young adults aged 16–25 and associations with abilities to navigate the health system. Methods: A population-based cross-sectional survey among 890 Norwegian adolescents was conducted during April–October 2020 using computer-assisted telephone interviewing. Rasch modeling, independent samples t-test, chi-square test, and binary regression models were used to analyze the data. Results: The HLS₁₉-DIGI scale was sufficiently unidimensional, whereas no differential item functioning or disordered response categories were observed. However, relatively poor targeting was revealed indicating too many easy items for the target population. Yet, a high proportion (54%) of low DHL proficiency in adolescents was observed, as well as DHL was positively associated with the abilities to navigate the health system. Conclusions: The HLS₁₉-DIGI scale is considered a sufficiently unidimensional and valid instrument for measuring DHL in adolescents, which may be a useful tool for health authorities, public health workers, and health service providers. While DHL affects adolescents’ abilities to navigate the health system, future research should measure and examine their ability to utilize digital health services, separately.