DOYLC

The concept of null in HL7v3 is very different from HL7V2.x (See my old post on Null values in HL7V2.x. http://healthcareinformatics3000feet.blogspot.com/2007/11/null-values-in-hl7v2x.html ). This is essentially to do with lack of support for optionality in HL7V3 – Reference Information Model which itself rose from the issues associated with optionality in HL7V2.x – see else where in this blog for strengths and weaknesses of HL7V2.x and HL7V3.0. At a high level we can say that in HL7V3 the multiple exceptional values, i.e. values other than recommended or allowed by message specifications are grouped under the banner of NullFlavor. nullFlavor is a property of every data type through ‘extension.’ This property is valued and communicated as part of a message when information is missing. The flavor provides the reason why the information is missing. This can be best illustrated by the following example The Character String with Code ( SC ) data type contains a character string that optio...

My previous posts clearly indicate that HL7 V3.0 represents a quite radical departure from the HL7V2.x standards in its development methodology. Most of the early adopters believed that the HL7V3.0 would replace HL7V2.x in its entirety, but the reality of the substantial investments in HL7V2.x systems by different organizations and vendors soon became apparent. The recent versions of HL7V2.x notably HLV2.6/HL7V2.7 added new features e.g. EHR messages which enhanced the capabilities of V2.x standards matching the features of Version 3.0. The areas area’s where V3 was supposed to solve V2.x problems e.g. Clinical Messages were found to be very work-intensive with issues pending around these domains. The last released normative edition HL7V2006 as shown in the Figure below indicate that some of the domains have not yet been approved for example Specimen domain( Informative).The final standards of some domains are in a trial form ( - DSTU = Draft Standard for Trial Use)only for example Pat...

After working for 10 years for a company i resigned my job last month and joined a new job last week.Iam not in a position to post anything new due to lack of time and lack of space(shifting to a new home as well). I will do so from August when i hope to get some decent time and space in my new home.But i could not resist posting two quick comments for those who came to my my blog with two search words and terms The first one is for the person who came to my blog with the long search query term “is there any other way of transporting hl7 message apart from mllp”. Yes there are , there are two alternative options to sending HL7V2.xmessages over MLLP one is sending it over HLLLP; For details see my post on HL7V2.x and Low layer protocols http://healthcareinformatics3000feet.blogspot.com/2007/12/hl7v2x-and-low-layer-protocols.html The other option is to use ebXML; use the normal ebxml header and put the hl7v2.x message in the MIME part; for discussions on ebXML structure see my ebXML and ...

The difficulties in mapping HL7V2.x to HL7V3.0 does not make a solution based on transformation and translation easy to implement. The difficulties encounter by initial adopters is making the total adoption of HL7V3.0 very difficult. Version 3 was created as a replacement for Version 2.x, but it is observed that the two versions are catering to distinct markets. However the impending success of major projects like UK-CFH is going to make HL7V3.0 a major standard and replace HL7V2.x in the longer run. It is a well known fact that big bang change of standards in applications deployed in clinical settings is a recipe for major disaster so proposal for a transition path to independent “V3-ready” implementations and “V3-ready” implementations of Version 2.x is required. The following approaches are proposals for an HL7V3.0 ready implementation. New HL7 V3 domains: Most of the domains which exist in HL7V2.x have equivalence in HL7V3.0 for e.g. ADT in V2.x has equivalent domain called Patien...

In continuation of my previous post this post lists the other issues associated with HL7 v2.x to HL7v3 translation Conformance Patterns: The other major issue with the transformation of messages is the behavior of application when a particular information exchange takes place. In HL7V3.0 apart from the trigger events and interactions there exists the notion of application role as senders and receivers. The application role is characterized as the entire set of interactions for which the sender and receiver are responsible for transmitting. HL7V3.0 clearly defines the possible interactions and the application behavior associated these interactions in the form of responses for which the sender and receiver needs to adhere to. The differences in messages between V2.x and V3.0 and absence of clear guidance on V2.x regarding application behavior on receipt of message makes the transformation exercise more difficult. Vocabulary: It is a well known fact that 80% of HL7 V2.x message failu...