Patient links enable users to select a patient's record from any patient-link-enabled application and all participating Patient-linked applications will synchronize the context to the same patient. The patient link is a common link with the Patient subject as the identity subject and is independent of any other subjects.
The context data identifier item for this subject is an alphanumeric patient identifier such as medical record number. A patient's name is not used as an identifier for Patient subjects because it isn’t universally unique. Different applications may use different identifiers for the same patient. Patient subject items use suffixes to identify the specific patient to different applications. Organizations implementing CCOW context management system define these suffixes. A Patient-Link-enabled application should be configurable to use the appropriate suffix (or suffixes) when getting or setting context data.
In addition to identifier items, the patient subject can also include corroborating and annotatation data items. The actual names, meaning, and data types used to represent the values for these context data items are defined in the Health Level-Seven Standard Subject Data Definitions document. The common context system's optional patient mapping agent can be used for mapping the identifiers for patients set by an application to additional identifiers known to mapping agent.
The process for performing a context change transaction is the same, in general, as common links. Applications are required to indicate to the user when the identifier of the patient is unknown to the application (i.e. case of stat admission), and should break its link upon user confirmation.