Enabling Patient-Centred (PC) care in modern healthcare requires the flow of medical information with the patient between different healthcare providers as they follow the patient's treatment plan. However, PC care threatens the stability of the balance of information security in the support systems since legacy systems fall short of attaining a security balance when sharing their information due to compromises made between its availability, integrity, and confidentiality. Results show that the main reason for this is that information security implementation in discrete legacy systems focused mainly on information confidentiality and integrity leaving availability a challenge in collaboration. Through an empirical study using domain analysis, observations, and interviews, this paper identifies a need for six information security requirements in legacy systems to cope with this situation in order to attain the security balance in systems supporting PC care implementation in modern healthcare
