HL7 is a well being information communication commonplace. HL7 model 2 covers the trade of affected person demographics (in any other case referred to as Affected person Grasp Index or PMI). HL7 V2 additionally covers different varieties of information corresponding to admission particulars, scheduling, orders and outcomes.
1. HL7 Interfaces are usually not plug and play
Sadly the HL7 V2 commonplace is interpreted in several methods by implementers and software program builders. The end result is 2 related however not precisely matching interfaces that require evaluation in an effort to determine the variations.
2. Translation of HL7 messages
As soon as the variations have been recognized, the messages from one utility must modified earlier than they are often processed by the opposite utility. Some translations could also be comparatively easy, corresponding to shifting a selected discipline from one place within the message to a different.
For instance the sending system might place an insurance coverage quantity within the insurance coverage phase (IN1). Nevertheless one other vendor might not help that phase and as a substitute expects the insurance coverage quantity to be positioned within the affected person identification phase (PID) or maybe in a proprietary phase.
Additionally it is frequent that fields could also be wanted to be moved primarily based on enterprise guidelines. Happily specialist software program known as interface engines are quire good at this job. For instance the iCan Integrator software program from Solar Microsystems (formally Seebeyond) supplies this type of performance.
3.Code desk mismatching
HL7 messages are affected by coded information. For instance the martial standing discipline comprises a coded worth corresponding to ‘M’ for Married, ‘D’ for divorced and so forth. Nevertheless the receiving system might count on ‘1’ for married and ‘2’ for divorced. Nationwide requirements have gone a protracted solution to tackle this difficulty. Nonetheless, the percentages are that a number of fields in your PMI message will should be mapped. Happily interface engines are additionally good at this job.
4.HL7 PID Identifier Listing
The affected person identification phase has three fields devoted to identifiers. PID-2 Affected person ID (exterior ID), PID-Three Affected person ID (inside ID) and PID-Four Different Affected person ID. The beneficial use of those fields has modified with successive revisions of HL7 (HL7 V2.1, HL7 V2.2, HL7 V2.3, HL7 V2.3.1, HL7 V2.4). Totally different distributors have interpreted these fields in a different way. Virtually everybody places the affected person’s medical document quantity (MRN) in PID-3.
If the scope of the interface is multiple hospital, then the MRN for one facility are distinguished from MRNs for different amenities by a facility code (handed as a subcomponent of the PID-Three discipline). The power code may have mapping (see Tip 2!).
In one other twist, the sending system might deal with a number of hospitals (e.g. a affected person administration system overlaying a number of hospitals) however the receiving system might solely wish to find out about sufferers from only one facility. A typical instance is a unbiased (however HL7 interfaced) functions corresponding to an ICU scientific utility. If the ICU system solely manages sufferers from one hospital, it can solely need HL7 messages for sufferers at that hospital. It might even solely need HL7 messages for sufferers admitted to the ICU. Interface engines are good on the filtering, routing and translating of messages require to make this occur.
5.Repeating fields
Fields that repeat, such because the tackle discipline (PID-11) may trigger issues. The challenges embody
- Totally different techniques help completely different numbers of repeats. For instance the sending system might help 7 addresses and the receiving system might help solely 2.
- The sending system might add, replace or delete the repeating discipline. Deleting a discipline could cause complications for the downstream system. Typically that is overcome by the downstream system changing the complete set of repeating fields every time.
6.Repeating segments
Segments that repeat, corresponding to ‘Subsequent of Kin’ (NK1) and alerts/allergic reactions (AL1/IAM) pose related challenges to repeating fields.
- Totally different techniques help completely different numbers of repeats. For instance the sending system might help 7 affected person contacts (despatched as 7 NK1 segments) and the receiving system might help solely 2.
- The sending system might add, replace or delete the repeating discipline. Deleting a discipline could cause complications for the downstream system. Typically that is overcome by the downstream system changing the complete set of repeating fields every time.
7.Shared fields
It’s not uncommon that the fields interfaced from the sending system can be modified within the receiving system. Mainly if the receiving system was not interfaced, then all the info would want to have been duplicated by manually typing into the appliance. Except the potential to edit information fields coated by the HL7 interface is ‘eliminated’ from the receiving system, adjustments made to the info (e.g. including or altering an allergy, deleting a affected person contact) by customers within the receiving system, could also be listing with the following HL7 message obtained, course of and saved for that affected person.
Happily persistent and diligent interface evaluation can overcome these and different challenges. HL7 PMI interfacing is likely one of the most typical and finest understood well being utility interfacing challenges. By making use of the following pointers you should have made a very good begin alongside the highway to a profitable HL7 PMI interface implementation.
