Hl7 difference visit number, account number, encounter number
Patient Account Number/Visit Number/Encounter Number - These are all often the same thing, they're just used interchangeably between different systems and organizations. The visit number is the unique identifier assigned by the healthcare facility(hospital, clinic, surgical center, etc.) that's given to a patient for that one particular visit to the facility.
The patient account number is located in PID.18 in an HL7 message.
Medical Record Number - The medical record number is the unique identifier given to a patient's medical record that covers all the encounters/visits of the patient within a facility - it's a living history of everything that has happened to the patient with regards to the healthcare facility he is visiting.
The medical record number is located in PID.3 in an HL7 message. - Edited.
To explain this, I'll give an example:
Little Timmy decided one day that he was going to jump off the roof of his mother's car because, well he's a child. As Timmy landed on the ground, he stumbled, hit the concrete pavement of the driveway, and broke his little arm.
As Timmy laid there crying, his mother ran out and immediately knew something was serious. So she rushed Little Timmy with his little broken arm to their local community hospital. Little Timmy had been there before, last year when he decided to jump off the roof of his house and break his ankle.
When Little Timmy and his mother gets to the hospital, they immediately head for the Emergency Room. An admit nurse pulls up Little Timmy's Medical Record Number, since he had been to the hospital a year earlier, and sees that the hospital already has a Medical Record on Little Timmy. Since he already has a Medical Record, there's less paperwork that he needs to do and therefore the admit nurse can admit Little Timmy - When she admits Little Timmy, a unique identifier for this particular visit (the visit number) is attached to Little Timmy's Medical Record Number so that they can document his stay in the hospital until he is discharged with a healing broken arm.
Since Little Timmy had a previous Medical Record, medical staff can go back and look at Timmy's last surgery and encounter with a broken bone and make decisions based on the present and past history. Little Timmy's medical record holds that history, with the visit of him coming to the hospital for his broken ankle from last year. This visit last year was also assigned a visit number, and was attached to his medical record number.
By having a visit number attached to each "visit" of the hospital that Timmy has undertaken, they can review past data to see if there are any chronic problems (Timmy likes to jump off of high places), and to assess if additional medical treatment or cautions should be taken.
Please feel free to ask me any questions if this confuses you.
An MRN is constant for one patient to represent them from a clinical data perspective for their entire life for an individual hospital.
Visit and Encounter are interchangeable and meant to represent a single visit to the hospital, also known as an episode of care. This is often used for tracking the care from a clinical perspective: chief complaint of symptoms, presenting diagnosis, testing and procedures performed, clinical documentation, discharge status and diagnosis.
Account number is typically associated with billing and may or may not be the same number as the MRN or the Visit/Encounter, depending on the individual hospital. An account number could be constant for a patient or gaurantor (person who is overall responsible for payment) or a new one may be generated for each episode, similar to a visit number, but frequently aggregates multiple related Visits/Encounters in to one account number for billing purposes.