Enterprise master patient index

An enterprise master patient index or enterprise-wide master patient index is a database that is used across a healthcare organization to maintain consistent, accurate and current demographic and essential medical data on the patients seen and managed within its various departments. The patient is assigned a unique identifier that is used to refer to this patient across the enterprise. The objective is to ensure that each patient is represented only once across all the software systems used within the organization. The essential patient data includes name, gender, date of birth, race and ethnicity, social security number, current address and contact information, insurance information, current diagnoses, most recent date of hospital admission and discharge (if applicable), etc.

EMPIs are intended to solve the common problem where multiple systems across the organization gradually become inconsistent with respect to the patient's most current data when the patient's information changes, and only one system is updated, i.e., the changes are not propagated to the others. A similar problem may be seen for non-healthcare organizations with respect to customer data.

Many software vendors use EMPI and MPI (master patient index) synonymously, because an MPI is only workable if it is used by all software applications across an entire enterprise: that is, "master" implies enterprise-wide scope.

In computing, an enterprise[-wide] master patient index is a form of customer data integration (CDI) specific to the healthcare industry. Healthcare organizations or groups of them will implement EMPI to identify, match, merge, de-duplicate, and cleanse patient records to create a master index that may be used to obtain a complete and single view of a patient. The EMPI will create a unique identifier for each patient and maintain a mapping to the identifiers used in each records' respective system.

An EMPI will typically provide an Application Programming Interface (API) for searching and querying the index to find patients and the pointers to their identifiers and records in the respective systems. It may also store some subset of the attributes for the patient so that it may be queried as an authoritative source of the "single most accurate record" or "source of truth" for the patient. Registration or other practice management applications may interact with the index when admitting new patients to have the single best record from the start, or may have the records indexed at a later time.

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