Interoperability gets more complex
- 7 November 2007
The NPfIT Local Ownership Programme (NLOP) will create further pressure on health care interoperability specialists, both within the NHS and its suppliers, with a huge devolution of general design responsibilities about to commence.
NLOP and the new Additional Supply Capability and Capacity (ASCC) suppliers will inevitably lead to greater variety in the new systems offered (to say nothing of existing systems), whilst raising expectations that these systems will interoperate and provide joined up health care for patients.
If anyone still believes that interoperability can be safely devolved to a black box in the corner, they need to wake up to reality. Interoperability is hard and expensive, not because it is intrinsically difficult, but because you have to specify and deliver exactly what you want. As with all things digital, interoperating computer systems are intolerant of the slightest error.
The trick is to make sure that the sender transmits only clean, accurate data, and never to expect the middleware, or the receiver, to sort out any discrepancies. Humans can deal with poor quality data, but computers cannot. The old saying of “garbage in, garbage out” can be revised to say “garbage in equals cost over-run”. Dealing with poor quality data sources is the primary cause of unplanned cost escalation, message structures themselves are seldom the issue and are relatively straight-forward.
This problem is even bigger than most people imagine because the number of links required increase exponentially with the number of systems involved.
A key benefit of HL7 then, is to tame this exponential explosion by delivering relevant specifications and, equally important, an ecosystem of conferences, working meetings, and other activities to support their maintenance and use. HL7 is a community of practice, which shares a common interest in enabling healthcare interoperability. As with any community of practice the enthusiasts do most of the real work, the contributors actively participate and the consumers lurk silently in the background.
HL7 is a bit like attending a gym; what you get out is directly related to the amount you put in. Active participation gives the greatest rewards.
In practice HL7 covers an increasingly broad domain. It all began with HL7 Version 2 (V2) about 20 years ago, well before Tim Berners-Lee had even thought of the worldwide web. The present version, 2.6, is still backward compatible with the original. Version 3 was developed to overcome the obvious deficiencies in V2 and has spawned CDA (Clinical Document Architecture), now adopted by NHS CFH for all clinical messages.
The most advanced version of CDA has the exciting title of “CDA Release 2 Level 3”, and provides most of the advantages of both human readable and coded documents. The human readable part is the basis of the National Care Records Service (NCRS), enabling a nationally readable clinical record, while the coded part populates the Secondary Uses Service (SUS), for use by the bean-counters.
Other recent HL7 developments are the new TermInfo Draft Standard for Trial Use (DSTU), which specifies how SNOMED CT is used with HL7 V3; new specifications for web-services and SOA (Service-Oriented Architecture); and functional specifications for both PHR (personal health records) and EHR (electronic health records).
This year’s annual HL7 UK conference takes place at the Hotel Russell, Russell Square, London, on 21-22 November. The talk will all be about making interoperability work and how to prepare for the next set of changes that our leaders are preparing for us.
Charlie McCay, Chair of HL7 UK said: “We all know that the ability to share information between disparate systems will be key to the workings of a responsive, safe and efficient health service. This conference is the best opportunity all year to spend two days in this country working through the issues together.”
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Tim Benson
