Patient Identity Matching without a National Identifier in IHE Profiles

In the US, because Congress won't even let anyone in the Federal government TALK about creating a national identifier (privacy concerns), we have to deal with multiple identifiers at every healthcare provider.  At least in Canada, the provinces can assign a provincial patient ID.  But, not here alas.

So, last week at the IHE Meeting, somebody asked what identifiers are supported in IHE Profiles, from this list.  I think this query may have been in support of this project.

First Name Last Name Middle Initial Suffix Date of Birth Gender Race Home phone number      Address ·         Street ·         State ·         Zip

Middle Name Cell phone Mothers Maiden Name Prefix Marital Status Alias or Previous name      USPS Address Identifier: ·         Last 4 of SSN ·         Driver License ·         Passport ·         Alien #

Multi Birth Birth Order Birth Place E-mail Previous Address Previous Cell Phone(s) Insurance ID Insurance Plan Name Previous Insurance Medicaid ID Medicare ID Biometric ID

So, I put together a spreadsheet mapping these identifiers to HL7 V2.5.1, PIX, PDQ, PAM, PIX/PDQ V3, XCPD, and PDQm.  It didn't take too long, just a couple of hours.

A quick summary: HL7 Version 2 and PAM supports all of these directly by name with the exception of the alien #, which is simply another identifier in Patient Identifier List (PID-3).  HL7 makes no distinction between current and previous at the field level, although other parameters can be used to distinguish a current address from a previous address, or a current insurance identifier from a previous one. The notion of previous is dependent upon the time the query is performed, rather than being an attribute of any of this data in any case.  The distinction between Alias and simply another name is slim enough that even though PAM doesn't support the alias field, you can use repetitions of the name field to get there.

I don't think race belongs in this list.  It's not an "identifier", because in the US, race is whatever the patient says it is at the time that they say it (see OMB Policy Directive #15), and shouldn't be completed by someone else.

PDQ in all its flavors (V2, V3, and Mobile/FHIR) supports most of these (in bold).  Some (in italics) require the use of the Pediatric Demographics Option.  XCPD is a super set of PDQ V3, so it too supports the same set.

PIX (in all its flavors) performs patient matching.  IHE doesn't specify the algorithm, because master patient directory systems use a variety of different matching algorithms, and these are often tuned to the location where they are used.  Tuning parameters for name matching in Arizona could differ greatly from those in Wisconsin or New York for example.

Any missing pieces could be added as national extensions to existing IHE profiles.