eHealth inequalities in a universal healthcare system: a cross-sectional study on the role of social determinants in knowledge and use

Objectives This study examines social inequalities in knowledge and use of eHealth tools in a region of Spain. Methods A cross-sectional analysis was conducted using data from the 2023 Basque Health Survey (n = 5,683). Prevalence of knowledge and use of digital tools was described stratified by sex and social determinants. Poisson regression models with robust variance were used to estimate prevalence ratios (PR) and 95% confidence intervals (CI) for not knowing or not using each tool. Models were progressively adjusted for age, healthcare utilisation, and knowledge in use models. Results Knowledge and use of eHealth tools varied substantially by age, education, and occupational class. The Web Appointment tool showed the highest levels of both knowledge and use. For women aged 80+, the probability of not knowing the tool was 5.09 times higher than for women aged 18–35 (95% CI: 3.54–7.32), and 4.34 (95% CI: 2.92–6.45) in men. Education and class gradients were strong, particularly in knowledge. For example, women with primary education had higher probability of not knowing the Web Appointment tool than university-educated peers (fully adjusted PR = 3.28, 95% CI: 2.39–4.51). Use of digital tools showed similar but smaller gradients. Differences by deprivation and health limitations were modest and less consistent. Conclusions Digital health inequalities in the usage of eHealth tools are strongly patterned by age and socioeconomic status, especially for knowledge; importantly, gaps in use remain even when tools are known, highlighting the need for targeted equity-focused strategies.