System records are different from the SBR in that each system record contains a system and local ID pair and only contains data from a specific system. The information in the system records of a patient profile is used to determine the best value for the SBR in that profile. If a patient profile only contains one system record, the SBR will be identical to that system record. However, if a patient profile contains multiple system records, the SBR might be identical to one system record but will more likely include a combination of information from all system records. Certain actions against a system record will cause the SBR to be changed, such as updating, deactivating, or merging a system record. Each active patient profile must have at least one active system record. If all system records in a profile are deactivated, then the entire profile will also be deactivated.