Sunday, February 05, 2006

Does the Grail exist?

EHR: Theory and practise

Electronic Health Records are tricky things. There is always a temptation for clinicians to focus on the straightforward, measurable, quantitative aspects of health information, such as blood glucose levels or Body Mass Index. The whole area of pathology tests results reporting appears to have driven some of the development in electronic messaging for health care. Similarly, information required for things such as billing under the casemix funding system used in the Victorian hospital system has also encouraged development of systems that collect highly structured information about procedures and simple categorised diagnoses used for prognostic billing methodologies.

While this work is valuable, I believe that it is dominating the debate and the attention of those working in the area of health information systems. More importantly, the approach is also receiving the lion’s share of the funding for health informatics. I still don’t mind a good barney over a beer about ontology and existentialism but I think I’m getting a little duller as I get older. I’m far more interested in practical approaches to solving problems. While the theory is interesting, I really believe that the theorists are overreaching.

The following exchange is from the OpenEHR-clinical mailing list. Now while I know that this is a list devoted to the OpenEHR approach to electronic health records, and in particular to discussions of clinical information, I think that the following exchange is indicative of just how far from practical realities the discussions are occasionally straying. See particularly my post at the bottom.

Date: Sat, 17 Sep 2005 12:24:46 +1000 [09/17/2005 12:24:46 PM EST]
From: Jon Hilton

Subject: Re: Antw: 'Actionability' of orders

William Goossen wrote:

I really would ask the OpenEHR community to adapt the HL7 RIM models for describing the propositional content and the UML activity diagrams and sequence diagrams for the illocutionary aspects of Acts.

This is an established model that does tackle many of the issues raised. If at implementation level particular attributes or mechanics of these models do not work, they can be adjusted or constrained. The advantage is obvious, we can work out common illocutionary expressions (placing orders with their dynamics does not differ for a battery of lab tests in an laborder , or a set of vital sign observations ordered by a physician to the nurse, or the request of a nurse to a physician to check a patient who's condition deteriorated). The principles of request, promise, event and validation hold for these examples.

Thomas Beale wrote: Hi William,

we would have preferred to be able to do this. But as we (and many others) have studied the problem over the years, the HL7 RIM looks less and less likely as a design basis for EHR information, including Instructions. Some of the problems (relating to just this topic) include:
  • the lack of clarity over whether the RIM is an ontology of information or an ontology of reality (in other words: is Observation a model of some information documenting observations, or a model of an Observation process/act itself?). The HL7 documentation contains numerous conflicting statements about this. One practical consequence is that modellers of RMIMs etc are unclear about what attributes are needed to ensure that some object is a clear documentation of something (in which case it is not an Act, it is a documentation of an Act) or somehow a model of that thing actually occurring in time.

  • the RIM doesn't clearly take account of workflow thinking, which we believe to be the sensible basis for modelling specifications of future acts and their execution. In particular, the modellig of future acts needs to include the primitives: activities, timing, triggers, plus the ability to archetype all this so as to connect a generic workflow representation to specific clinical workflows.
Quite a number of experts are studying the ontological and other technical aspects of the RIM; I expect that we will be able to benefit from their research in the near future.

Jon Hilton wrote:

There may well be issues with the ontological basis of the HL7 RIM. I can understand the wish to establish an agreed framework for ontological description as a basis for continued work on describing health care information.

The challenge is still to make some practical progress without getting bound up in arguments such as the ones expressed in this mailing list - as exemplified by this thread (important though they may be). I think the problem is unavoidable if we start with an abstract concept of EHR and insist on a reductionist approach - building the record back up from agreed atomic expressions.

Viewed like this, it seems to me that both the openehr and HL7-RIM approaches to EHR are like trying to describe a sunset by breaking down the experience into agreed atoms of meaning within a rigid hierarchical structure. There is nothing wrong with this per se in the context of EHR, as a record is unavoidably bounded by numerous interacting constraints. I wonder though if the inherent limitation of the reductionist approach is not being overlooked in the broader approach to EHR implementation. We can (and must) work with structure, providing that the structure is consistent with identified business process needs. If that is so, then a high level description will be immediately usable in real systems, even though much of the detail under that description is not defined.

Surely it should be possible to come up with some agreed high level ontologies and implement systems that support this level of ontology without being too prescriptive in defining the lower levels. It is then possible to refine the concepts through refining the business modelling they are based on and the systems that implement them. As this is achieved the next layer of ontological definition for important processes will identify itself. At this stage, in the area of Primary and Community Health, Ambulatory Care and Chronic Disease Management (my particular areas of interest) I believe that this approach translates into a focus on ontologies AND SUPPORTING INFRASTRUCTURE (sorry for yelling!) for
  • Patient/Client (Identification, digital certificates, basic demographics, possibly allergies, etc)
  • Provider (Identification, digital certificates, speciality, qualifications, etc)
  • Service (context of the provider - service type, location, organisation etc.)
  • Communications activities (referral , orders, etc and their responses)
Where clearly defined and agreed ontologies exist they can be incorporated at the appropriate level. For example pathology orders and results would fit in to Communications activities, Allergies would fit under Patient/Client, etc. Otherwise, we should be prepared to support storage and sharing of unstructured information until such time as we can define the structures. For patients with complex conditions who are being maintained at home, a list of who has been involved in providing care and their contact details is arguably of more value to a general practitioner than the details of the patient's last FBE (unless it was ordered by the GP - in which case we would hope that existing systems will suffice for now.)

I believe that the required descriptions are essentially there in both the the openehr and HL7 RIM ontologies. My real problem is that I don't see anyone in the openehr mailing lists clamouring for the infrastructure initiatives required to support the broad implementation of ontologies at this level. There is something of the chicken and egg about this (how can we define the required infrastructure without the ontologies) I would argue that the detail of these ontologies will change for many reasons, including responses to changing healthcare practice, government policies, etc. and we should get on with implementing an agreed minimal set of directories, identification schemes and services in the above areas as basic infrastructure based on simple (minimalist even) high level ontologies. This would provide a platform for getting on with the more detailed work of refining ontologies in specific contexts. I realise that the issues of implementation are specific to particular jurisdictions, and it is possible that many of you are defining your ontologies in just the manner I am describing. As an Australian, I wonder what our role in this is given that we don't have any of the required infrastructure in place - nor any apparent source of funding to support its development?

I realise that this may appear to be a simplistic approach but I feel that it is important not to lose sight of the real goal - we want to build useful systems to support service providers in health care - all of them, from providers of needle exchanges, drug and alcohol counselling, home help and meals on wheels to general practitioners, respiratory physicians, orthopaedic surgeons, medical researchers and epidemiologists. In order to do this effectively, we should be wary of biting off more than we can chew. When it comes to meeting the needs of the diverse range of actors and actions found in healthcare, we need to start by agreeing on very simple generic concepts, implement them, and work our way down - rather than diving in to the detail while trying to keep the 'big picture' in mind. This is not intended to denigrate such efforts, but rather to try and encourage an environment where they can flourish and really make a difference.

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