Background: Approaches to implementing online record access (ORA) via patient portals for minors and guardians vary internationally, as more countries continue to develop patient-accessible electronic health records (PAEHR) systems. Evidence of ORA usage and country-specific practices to allow or block minors' and guardians' access to minors' records during adolescence (i.e. access control practices) may provide a broader understanding of possible approaches and their implications for minors' confidentiality and guardian support.

Aim: To describe and compare minors' and guardian proxy users' PAEHR usage in Sweden and Finland. Furthermore, to investigate the use of country-specific access control practices.

Methods: A retrospective, observational case study was conducted. Data were collected from PAEHR administration services in Sweden and Finland and proportional use was calculated based on population statistics. Descriptive statistics were used to analyze the results.

Results: In both Sweden and Finland, the proportion of adolescents accessing their PAEHR increased from younger to older age-groups reaching the proportion of 59.9 % in Sweden and 84.8 % in Finland in the age-group of 17-year-olds. The PAEHR access gap during early adolescence in Sweden may explain the lower proportion of users among those who enter adulthood. Around half of guardians in Finland accessed their minor children's records in 2022 (46.1 %), while Swedish guardian use was the highest in 2022 for newborn children (41.8 %), and decreased thereafter. Few, mainly guardians, applied for extended access in Sweden. In Finland, where a case-by-case approach to access control relies on healthcare professionals' (HCPs) consideration of a minor's maturity, 95.8 % of minors chose to disclose prescription information to their guardians.

Conclusion: While age-based access control practices can hamper ORA for minors and guardians, case-by-case approach requires HCP resources and careful guidance to ensure equality between patients. Guardians primarily access minors' records during early childhood and adolescents show willingness to share their PAEHR with parents.