Interfaces, HL7, & Interface Engines

 

Interfaces, HL7, & Interface Engines

 

Just about all hospitals or other Healthcare organizations likely have many different technologies in use by clinicians, administrative staff, billing offices, and others. It is common for these systems to be developed on different platforms, and coded in different programming languages. Without a common standard, the data between these systems would remain in silos, resulting in:

  • Users logging into multiple systems
  • Inability to make good use of data
  • Risk to patient safety
  • Inefficient workflows

Fortunately, Healthcare IT systems do have a standard for sharing data among multiple systems. It is Health Level Seven, commonly referred to as HL7. Some of the benefits of HL7 are:

  • Industry accepted standard for communicating data, even among competing systems
  • Flexibility to tweak the messaging standard without causing huge problems
  • Relatively easy to learn messaging format
  • Seamless appearance to non-technical users

Videos on Interfaces, HL7, & Interface Engines

I have created two videos so far to help you get started with learning HL7. Please have a look at these videos before moving on to the other linked resources:

How To Read HL7 Messages

 

There are lots of sites to help you learn about the various HL7 messages, but many are lacking in usability, and are not well-suited for the beginner to interfaces.  I’ve weeded out some and have found these to be useful:

  • HL7.org – This is the official international standards organization. The reading here is a bit dry for some one who is brand new to HL7.
  • Corpoint HL7 Resources  – This is a vendor operated site from Corepoint Health, who provides HL7 products, including an interface engine. I don’t have any official relationship with them, I don’t use their products, and they are not paying me anything to reference their sites. They just happen to have good reference materials. This page is the starting point for many aspects of interface messages.

HL7 Sample Messages

Once you’ve viewed some videos and studied the reference materials, you’re ready to look closer at some other HL7 messages. In the videos you’ll become familiar with the concept of “counting pipes”, the pipe symbol | that separates the data into segments.

ADT Admit Message – ADT^A01

This is an ADT Admission message. Notice that it has basic info about the patient contained in the PID (patient ID) segment. NK1 is next of kin, PV1 is the patient visit segment, and allergies are in the AL1 segment.

MSH|^~\&|EPIC|SYS|HOSP|ADT|201502031126|SEC|ADT^A01|001199|P|2.3
EVN|A01|201502031126
PID|||12001||SIMPSON^HOMER||19670824|M|||123 Fake St.^^Springfield^OR^90020^USA|||||||
NK1|1|SIMPSON^MARGE|WIFE||||||NK
PV1|1|I|2000^2012^01||||11277^SIMPSON^BART^J|||SUR||-||ADM|A0-
AL1|1||^Penicillin||Hives

 ORM Message – Orders message that is placed for a Lab test

MSH|^~\&|HIS|EPIC|LAB|HOSP|20140307110114
||ORM^O01|07110114|P|2.3
PID|||12001||SIMPSON^HOMER||19670824|M|||123 Fake St.^^Springfield^OR^90020^USA|||||||
PV1||O|OP^PAREG^||||2342^SIMPSON^HOMER|||OP|||||||||2||||||||
|||||||||||||||||20140307110111|
ORC|NW|20140307110114
OBR|1|20140307110114||12345^Urinalysis^L|||20140307110114

Note that I’ve bolded the ORC segment. This is a NEW (NW) order, and ORC:2 has an order control number. After the order is placed, it then gets resulted by a Lab, who then sends the following message with the same order control number in the ORC segment. This is what links the two messages together.

ORU Message – Results coming back in from Lab test above

MSH|^~\&|HIS|EPIC|LAB|HOSP|20140307110114||ORM^O01|07110114|P|2.3
PID|||12001||SIMPSON^HOMER||19670824|M|||123 Fake St.^^Springfield^OR^90020
^USA|||||||
PV1||O|OP^PAREG^||||2342^SIMPSON^HOMER|||OP|||||||||2|||||||||||||||||
||||||||20140307110111|
ORC|RE|20140307110114
OBR|1|20140307110114|20140307110114|12345^Urinalysis^L|
OBX|1|NM|013060^Specific Gravity^L||1.010||1.005-1.030|||N|F|
OBX|2|CE|013045^Urine-Color^L||Y^Yellow^L||Y|||N|F|
OBX|3|ST|013052^Appearance^L||Hazy||Clear|A||N|F|

MFN  – Master File Message To Update Staff

HL7 is not just for clinical messages. This is an example of an interface that updates user information, in this case a physician.

MSH|^~\&|STAFFSYS|B3|LABSYS|B3|201410121201||MFN^M02|DG29AFSC|P|2.3
STF||DRID12|PHYSICIAN^NICK^””||||A||HOSP_ID^HOSPNAME|3098522222
|ADDRESS^ADD2^CITY^ST^ZIP

Related Reading

A good next step is to check out this related post on how many Healthcare IT systems are structured. It covers why there are different ‘copies’ or environments of given software. This understanding is essential to build a good Healthcare IT foundation.

Summary
Article Name
Interfaces, HL7, & Interface Engines
Description
Introduction to interfaces, HL7, & interface engines. Covers the basics of Health Level 7, the protocol for transmitting and formatting data in healthcare.
Author
LearnHealthTech.com