Tonight's HIT Standards Q&A Tweetchat (5:00PM ET) will be on IHE Profiles from IT Infrastructure dealing with patient identity management.
Originally, it was going to cover ITI, Patient Care Coordination, and Quality, Public Health and Research domains. But, last week there were a number of questions about Patient Identification, and I hope we focus on what IHE has to offer in this space. IHE IT Infrastructure profiles support the following.
First, there is Patient Identity Cross Referencing (PIX). This profile is designed to allow an EHR or other Health IT system to integrate with a Master Patient Index using HL7 Version 2.3.1 and 2.5.1 messaging. If you know the ID of the patient in one domain, this profile allows you to find the ID of the patient in another domain.
Next there is Patient Demographics Query (PDQ). This profile allows you to search for patient identities based on patient demographics. You can locate all of the matching identities, or just those from a specific identity domain. This also uses HL7 Version 2, but this time, just 2.5.1 to support the queries. PIX/PDQ are rarely found implemented separately, but they are written as separate profiles.
A few other countries require the use of HL7 Version 3 messaging to access this information, so IHE created a HL7 Version 3 edition that has the same capabilities, called PIX/PDQ Version 3 (PIXV3 and PDQV3).
Identifying patients from one HIE who might have records in another is a more significant challenge. The Cross Community Patient Discovery (XCPD) profile builds off of the PIX/PDQ V3 work. It needs to use web services to perform the exchange for various reasons.
Finally, there is Patient Administration Management (PAM) which uses HL7 Version 2 to address general patient administration (ADT) messaging, which is where a patient identity usually enters the system.
One reason for the focus on Patient Identity is the ONC Advance Notice of Proposed Rulemaking on Metadata for Health Information Exchange. You can find my thoughts on that rule here, and an initial post and a more detailed on with answers from John Moehrke as well.
I look forward to your questions.