How to Change HL7 Segment and Field Definitions in Caristix Cloak

One of our Cloak customers is de-identifying close to 14 GB of clinical data coming from several healthcare information systems (including 2 ADTs and a lab system) at an IDN. This customer is asking some great questions that would help other Cloak users get more out of the software. Here’s an excerpt from our conversations.

The NK1 segment is giving me trouble. Specifically, field 5, the address. I created a sample message with this as the NK1.5 content:

123 EASY ST^Arlington^VA^22207

The NK1 segment is listed as NK1.5.2 as being “other designation”, not the city, thus throwing off my address conversion. I have no means to identify subcomponent 2 as the city, I’m “stuck” with it being “other designation.”

It looks like the NK1 segment in the logs doesn’t follow the standard… (surprise, surprise;). In fact, based on the HL7 standard, the address would be stored in NK1.4 and city in NK1.4.3. It appears to be a naming issue within the data. You can modify the HL7 profile/specification that Cloak uses so the HL7 reference profile represents the data you’re working with (as opposed to trying to conform to the official HL7 specification). In other words, you can change the specification to remove the “other designation” field in the HL7 profile.

To do this, you would need either Caristix Conformance or Reader software. Reader is a free download available here.

Here’s the procedure:
1. Open Conformance or Reader.
2. Make a copy of “HL7 v2.6” profile in “New Folder”.
3. Rename the profile to something that make sense to you.
4. Browse to the NK1 segment and expand it.
5. Browse to NK1.5 and expand it.
6. Delete the “other designation” field.
7. Save the profile.

8. Go back to Cloak.
9. From the menu bar, go to Tools, Options, Reference Profile.
10. In the list of profiles, select the profile you just modified.
11. Click OK. The NK1.4.2 field name is now city.