HL7 is a well being information communication customary. HL7 model 2 covers the change 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 similar to admission particulars, scheduling, orders and outcomes.
1. HL7 Interfaces usually are not plug and play
Sadly the HL7 V2 customary is interpreted in several methods by implementers and software program builders. The result is 2 comparable however not precisely matching interfaces that require evaluation with a view to establish 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, similar to transferring a selected subject from one place within the message to a different.
For instance the sending system could place an insurance coverage quantity within the insurance coverage phase (IN1). Nevertheless one other vendor could not assist 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.
It’s also widespread that fields could also be wanted to be moved based mostly 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 suffering from coded information. For instance the martial standing subject incorporates a coded worth similar to ‘M’ for Married, ‘D’ for divorced and so forth. Nevertheless the receiving system could count on ‘1’ for married and ‘2’ for divorced. Nationwide requirements have gone an extended strategy to deal with this subject. Nonetheless, the chances are that a number of fields in your PMI message will must be mapped. Happily interface engines are additionally good at this job.
4.HL7 PID Identifier Record
The affected person identification phase has three fields devoted to identifiers. PID-2 Affected person ID (exterior ID), PID-3 Affected person ID (inner ID) and PID-4 Various Affected person ID. The really helpful 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). Completely different distributors have interpreted these fields in a different way. Nearly 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-3 subject). The ability code might have mapping (see Tip 2!).
In one other twist, the sending system could deal with a number of hospitals (e.g. a affected person administration system overlaying a number of hospitals) however the receiving system could solely need to find out about sufferers from only one facility. A typical instance is a unbiased (however HL7 interfaced) functions similar to an ICU scientific utility. If the ICU system solely manages sufferers from one hospital, it is going to 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 deal with subject (PID-11) may additionally trigger issues. The challenges embody
- Completely different techniques assist completely different numbers of repeats. For instance the sending system could assist 7 addresses and the receiving system could assist solely 2.
- The sending system could add, replace or delete the repeating subject. Deleting a subject may cause complications for the downstream system. Generally that is overcome by the downstream system changing all the set of repeating fields every time.
6.Repeating segments
Segments that repeat, similar to ‘Subsequent of Kin’ (NK1) and alerts/allergy symptoms (AL1/IAM) pose comparable challenges to repeating fields.
- Completely different techniques assist completely different numbers of repeats. For instance the sending system could assist 7 affected person contacts (despatched as 7 NK1 segments) and the receiving system could assist solely 2.
- The sending system could add, replace or delete the repeating subject. Deleting a subject may cause complications for the downstream system. Generally that is overcome by the downstream system changing all the set of repeating fields every time.
7.Shared fields
It’s not uncommon that the fields interfaced from the sending system will also be modified within the receiving system. Mainly if the receiving system was not interfaced, then the entire info would wish to have been duplicated by manually typing into the applying. Until the aptitude to edit information fields lined 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 record 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 without doubt one of the commonest and greatest understood well being utility interfacing challenges. By making use of the following pointers you’ll have made a great begin alongside the street to a profitable HL7 PMI interface implementation.
