Digital Health Literacy of Adolescents and Its Association with Vaccination Literacy: The First Evidence from Lithuania.

BACKGROUND: Health literacy, including its digital and vaccination-specific components, is essential for informed health decision-making in adolescence-a developmental period when health attitudes and behaviors are shaped and may persist into adulthood. Although the importance of these competencies is increasingly recognized, little is known about the relationship between digital health literacy (DHL) and vaccination literacy (VL) among adolescents. The aim of this study was to investigate the associations between DHL and VL among Lithuanian adolescents, and to evaluate the psychometric properties of the Digital Health Literacy Questionnaire (HLS19-DIGI) and the Vaccination Literacy Questionnaire (HLS19-VAC) in this population. METHODS: A cross-sectional survey was conducted with 9-12 grades students from Lithuanian gymnasiums using HLS19-DIGI and HLS19-VAC instruments. Analyses included confirmatory factor analyses for validity, McDonald's omega for reliability, ANOVA and chi-square tests for group comparisons, and linear regression to evaluate DHL-VL associations, adjusting for gender, grade, and frequency of digital resource use. RESULTS: A total of 792 students (42.0% male; mean age 16.4 years) completed the survey. The HLS19-DIGI (CFI = 0.945, TLI = 0.923, RMSEA = 0.081) and HLS19-VAC (CFI = 0.986, TLI = 0.959, RMSEA = 0.089) showed satisfactory structural validity, and both scales had good reliability (0.757 and 0.803). Mean DHL and VL scores were 78.28 (SD = 24.24) and 82.64 (SD = 27.22), respectively. Over half of the participants had excellent DHL (55.7%) and VL (63.4%). DHL was a strong predictor of VL (β = 0.429, p < 0.001). The frequency of digital resource use was not significantly related to VL. CONCLUSIONS: Higher DHL is associated with higher VL, suggesting that skills in searching for, appraising, and applying online health information can enhance informed vaccination decision-making. Interventions delivered through trusted channels, such as schools and healthcare providers, should aim to strengthen both literacies, address misinformation, and foster critical evaluation competencies to support vaccine uptake in youth.