3M™ Enterprise Master Person Index (3M EMPI)

Product Overview

  • Cross-references local patient identification systems to preserve the investment in legacy systems
  • Uses Advanced Matching Logic to help accurately identify patients and avoid duplicate records
  • Links acute and ambulatory data to provide an electronic medical record with both demographic and encounter data from across the care continuum

The 3M™ Enterprise Master Person Index (3M EMPI) tracks data for:

  • Patients who have seen a physician or been admitted to a hospital
  • Members of health plans and wellness facilities
  • Subscribers with no healthcare encounters

No matter where an individual receives care, the 3M EMPI can save registration and admissions personnel time at check-in by giving them access to that person’s most current data. As patients move between care sites without having to repeat their admissions data, they perceive the enterprise as a single organization that recognizes them as individuals and understands their healthcare needs.

Single Unique Identifier
When a new record is added to the 3M EMPI, a unique, system-wide identification number—called the Person Number—is generated for that individual. A key component and important first step in creating longitudinal patient records, the Person Number links external identifiers, demographic data, and encounter data records into a single data set.

Today, the Person Number is frequently used to link the patient’s records from interfaced clinical systems, such as radiology, pharmacy, and laboratory. When a National Patient Identifier (NPI) comes into play, the 3M EMPI can be adapted to link to that identifier as well.

The Person Number benefits both users and information systems managers, because current registration methods don’t have to be replaced or a single medical record number format enforced across diverse information systems. Users can still locate patient information with the medical record numbers or other permanent identifiers used on the organization’s legacy systems. Most important of all, the 3M EMPI makes it possible for clinicians to identify and view in a single glance an entire medical record from multiple encounters across the care continuum. Besides saving clinicians both time and effort in locating records, the 3M EMPI allows for easy access to available data and the ability to share it with other colleagues and facilities, which can help improve patient care and delivery.

3M™ Enterprise Master Person Index Advanced Matching Logic
The three most common causes of duplicate records are human error, identity fraud, and attempts to merge data sets from individual systems. But by using probabilistic logic rules and attribute weighting, the Advanced Matching Logic (AML) in the 3M Enterprise Master Person Index (3M EMPI) can help medical record and information systems personnel by limiting the number of duplicate records entering or already existing within the system. The end result? A cleaner, more manageable index.

Clearing Up The Gray Areas
When it comes to identifying a patient, data is rarely black and white. Registration personnel try to reconcile the gray areas during the admissions process, but consider these possibilities for misidentifying one person:

Benjamin J. Smith 48801 ADT
B. Smith A9987 Laboratory
Ben Smith 67832 ADT
Benjamin Smith 155092 Clinic
B. J. Smith 44976 Radiology

Expanding The Power of the 3M™ EMPI
The 3M EMPI’s Advanced Matching Logic uses probabilistic matching logic rules to analyze multiple data fields and calculate the probability that multiple medical records really belong to one individual. Thanks to these rules, the software can:

  • More intelligently compare a multitude of data elements, anticipating possible mistakes and variations
  • Match patient records even when their individual data elements are not exactly the same
  • Help overcome inconsistencies created by variations in data-entry practices

More importantly, the matching logic can quickly calculate the probability of a record match and present the user with the information needed to determine if two records belong to one patient. In the case of Mr. Smith, AML can resolve whether Ben Smith and Benjamin J. Smith are the same person by comparing information like the Social Security number and date of birth on both records. AML automatically identifies and logs suspected duplicates for later resolution, and can help prevent duplicate records from entering the index in the first place.

How the Matching Logic Works
A patient’s data can be accessed actively (from a legacy application), or passively transmitted over an interface from another legacy information system. In either active or passive mode, a record search is completed whenever unique identification criteria (e.g., an enterprise ID number or facility ID/medical record number) are available.

However, if a unique identifier for a record is not available, or no exact match for the identifier can be found, the AML is called into play. Before a new record is added to the 3M EMPI, the matching logic searches for and compares incoming data with existing demographic data contained in the 3M EMPI. Matching one patient record to another consists of:

  • Normalizing all incoming data elements to help facilitate reliable comparisons
  • Querying the 3M EMPI patient records and building a candidate list
  • Comparing each candidate’s data with incoming data and assigning a score that reflects the probability of a match between the two
  • Sorting the candidates by their scores and arranging them from highest to lowest probability for the user
  • Returning the best candidate(s) to the user

Data is normalized to facilitate searches and comparisons. How data is normalized depends on the data type. For example, a last name has rules that convert the name to uppercase and create a phonetic version of the name, while a first name will convert to uppercase, produce a phonetic version of the name and link to possible aliases. An administrative user can select which rules are applied to each field.

When querying, the incoming fields are first normalized and then used to retrieve candidates from the database. Candidates are then scored based on how well they match the query data. Exact matches receive more points than normalized matches. Each field is given a weight based on how unique that kind of data is in the database, and administrative users can adjust those weights.

Duplicate Checking Log and Tool
In the example below, records scoring in the 95–50 percent range are considered suspicious enough to warrant further examination. Records in this range are logged to a file for a user to review and reconcile with a client application tool provided for viewing and merging possible matches. In that tool, the new patient record and existing patient record are displayed side by side, helping the user resolve whether they are the same individual and merge the records if they are.


100 – 95% Modify the 3M EMPI by updating the existing record of the “best matching candidate” (i.e., the candidate with the highest score).
< 95 – 50% Create a new patient record in the 3M EMPI, but log the records as possible duplicates to the duplicate checking report file (where users resolve them using the duplicate record resolution tool).
< 50% Create a new patient record in the 3M EMPI.

An Identity Management Solution
A wide variety of enterprises can potentially use the 3M EMPI for identity management; after all, it is a master person index, not just a master patient index. For example, it can be used in other public safety or public health settings (such as prisons, provider registries, etc.) and manage identity information of next-of-kin, guarantors, providers, etc.

Currently, the 3M EMPI is largely used to reconcile the very common and costly problem of duplicate patient records. AML’s probabilistic logic rules and attribute weighting are the keys to detecting duplicates, resulting in a cleaner, more manageable index. The 3M EMPI is a tool that can help organizations reduce the time and money spent on reconciling duplicates and sustaining their information systems.

Encounter Tracking and Record Locator Service
Whenever an encounter (any inpatient or outpatient visit with an admit date and billing number) is added to the 3M EMPI, it becomes part of the individual’s long-term history. Each encounter is uniquely identified, so users always have access to the data, regardless of the facility or department in which the care was given. Additionally, this capability can be used as a record locator service to facilitate queries of disparate clinical systems to assemble a complete view of the clinical data captured for a patient.

Active or Passive Interfaces
The 3M EMPI can either operate on its own or as part of a complete electronic medical record solution. A patient’s data in the 3M EMPI can be accessed interactively from another compatible application, or passively transmitted over an interface from another information system. Each entity in an enterprise or HIE can select its own solution, depending on its existing systems and business goals.

Record Structure and Content
Each record in the 3M EMPI contains data items that contribute to identifying the individual and make the record unique. Some items, such as social security number, passport number, and birth date, generally remain stable over the individual’s lifetime, but others (last name, addresses, and phone numbers) may change frequently. The 3M EMPI is designed to accept updates to all identifying information except the Person Number.

Audit Trails
If an enterprise or HIE needs to audit the 3M EMPI’s transactions, the system records each update, the transaction’s date and time, and the identity of the user who performed the update.

Service-Oriented Approach
The 3M EMPI is built using a service-oriented approach that supports its own web front-end as well as provides an application programming interface (API) that allows it to readily integrate with other applications. An organization can use other vendor’s products or create its own custom applications on separate hardware platforms to communicate with the 3M EMPI.

Call Today
For more information on how 3M solutions can assist your organization, contact your 3M sales representative, call us toll-free at 800-367-2447.