The Hong Kong Hospital Authority's information architecture.

Since 1994, the Hospital Authority has been developing and deploying clinical applications at its constituent 39 hospitals and clinics. The Clinical Management System (CMS) is now used by over 4000 doctors and 20000 other clinicians to document and review care. Since 1999, the territory-wide integrated Electronic Patient Record (ePR) has given clinicians a longitudinal view of the data collected through the CMS and its adjunct systems. The ePR currently has nearly 3TB of data covering 44 million episodes for 6.4 million patients. This paper describes the Hospital Authority's Information Architecture, which allows the ePR to accept and integrate any clinical information from any internal or external system. The ePR operates in a high volume and high performance environment, yet only requires low maintenance, while still retaining the information structure and semantics required for advanced applications.