patientID

A patient identifier, often referred to as a patient ID or patientid, is a unique value assigned to an individual within a healthcare system to distinguish their records from those of other patients. It enables reliable linkage of clinical data, administrative information, and billing records across applications such as electronic health records, laboratory systems, and scheduling platforms.

In practice, patient identifiers serve as the primary key for patient records within an organization. They can be internal numbers generated by a hospital or clinic (such as a medical record number or MRN) and may also include national or regional identifiers where available. Many systems support multiple identifiers for the same person, stored as a set of identifiers associated with a single patient record to support interoperability and patient matching.

Formats and standards vary by country and institution. Some identifiers are purely numeric, others alphanumeric. In interoperable environments, identifiers are accompanied by an identifying system or issuing authority (for example, the local hospital, a national health service, or a government-issued number) and may appear in standardized data formats or as part of the identifier elements within health information exchange protocols such as HL7 or FHIR. The FHIR standard, for instance, uses a Patient resource that includes an id and a list of identifiers with system/value pairs.

Key considerations include accuracy and stability of the identifier, management of duplicate records through a master patient index, and strict privacy controls. Security, access auditing, and compliance with privacy laws are essential to protect sensitive health information linked to patient identifiers.