Adverse events (AEs) in healthcare are commonly reported internationally. However, the structure of event reporting varies based on the healthcare service system, legislation, and the safety culture among service providers. Based on several studies, medication management-related errors have a long history of being reported. However, there is evidence that information management-related errors increase workload, costs, and patient suffering. This study focuses on AEs reported in the categories of medication and information management in a national reporting system. Our aim was to determine whether patients were informed about these errors and whether there were any relationships between the severity of these errors and the disclosure to patients. Based on the results, almost all errors in both categories without any harm to patients were disclosed to patients. Patients were not informed about 40% of information management-related AEs that caused severe harm.