CEHRS Master Patient Index (MPI) and Record Integrity

Question 1

What is the PRIMARY function of a Master Patient Index (MPI) in a healthcare organization?

Accepted Answer

To uniquely identify each patient and link all their records across the health system

Answer

The MPI serves as the central patient identity registry for a healthcare organization. It assigns a unique medical record number (MRN) to each patient and links all encounters, records, and data across facilities or departments to the correct person — preventing misidentification and fragmentation of care.

Question 2

A 'duplicate record' in the MPI occurs when:

Accepted Answer

The same patient is assigned two or more separate medical record numbers

Answer

A duplicate MPI record means one individual has multiple MRNs in the system — typically created when a patient is registered more than once due to name variations, typographical errors, or failure to find the existing record. This fragments the patient's history and creates care coordination risks.

Question 3

A 'record overlay' is the MOST dangerous MPI error because it means:

Accepted Answer

One patient's clinical data is written into a different patient's medical record

Answer

In a record overlay, Patient A's MRN is used to document care that actually belongs to Patient B — or vice versa. This is a critical patient safety event: providers may make clinical decisions (medications, surgery, transfusions) based on another person's allergies, blood type, or diagnoses. Overlays are far more dangerous than duplicates.

Question 4

An EHR specialist suspects a patient has two separate MRNs in the system. What is the FIRST step that should be taken?

Accepted Answer

Verify through demographic and clinical data review that both records belong to the same patient before initiating any action

Answer

Merging records without verification is dangerous — two patients could share similar demographics, and a premature merge would create a record overlay. The correct first step is to carefully verify identity through multiple demographic identifiers and, if available, photo ID or clinical evidence before any merge is initiated.

Question 5

Which combination of patient demographic fields provides the STRONGEST confidence in a probabilistic patient-matching algorithm?

Accepted Answer

Social Security Number, date of birth, and full legal name

Answer

Probabilistic matching assigns weighted scores to each demographic field. SSN is highly unique per individual; date of birth adds a strong independent constraint; and full legal name adds a third distinct dimension. No single field is sufficient — the combination dramatically reduces the probability of a false match.

(CEHRS) Certified Electronic Health Records Specialist Practice Test

(CEHRS) Certified Electronic Health Records Specialist Practice Test

CEHRS Master Patient Index (MPI) and Record Integrity