HL7 and negation

Heather Leslie heather.leslie at oceaninformatics.com
Mon Jun 13 23:56:35 EDT 2016

Hi Thomas,

Point 3 is not simply about ‘not applicable’ – it is about the need to assert a clinical statement that the examination could not be done (as opposed to NA or didn’t feel like it), often for medicolegal purposes. It is more than ‘not applicable’ and often needs a reason why to be asserted. Classic example is a patient who has had an eye injury and concomitant head injury – the pupils are one of the physical signs that are monitored closely to track potential intracranial issues and if the pupils are not able to be visualised due to swelling or other trauma you may miss a clue as the patient deteriorates. We need to record that the clinician effectively looked but couldn’t complete the examination due to <insert reason of choice here>

Agree that Point 4 is a not applicable situation – for this patient only, but the template as a whole might be applicable for most others.

I know that it has been requested for many years but we also need reasons for selection of many of the existing RM null flavours…



From: openEHR-clinical [mailto:openehr-clinical-bounces at lists.openehr.org] On Behalf Of Thomas Beale
Sent: Saturday, 11 June 2016 8:29 PM
To: openehr-clinical at lists.openehr.org
Subject: Re: HL7 and negation


very nice analysis. Points 3 and 4 are a 'not applicable' idea, which needs to be catered for as such I think.

- thomas

On 08/06/2016 14:50, Bakke, Silje Ljosland wrote:
Hi Gerard,

I don’t have time to look through the use cases right now, but I thought I should give a general outline to how we handle negation in openEHR archetypes.

Basically, there isn’t a single way that works for all use cases, but we’ve worked out a few patterns that seem to work:

·       Some concepts are very safety critical, where you should never be able to confuse positive presence with negation. Examples of these are medications, adverse reactions, problems/diagnoses, family history, procedures, in some cases symptoms, and possibly implants. Negation of these need to be handled by separate “Exclusion of X” archetypes, which makes it impossible to query for something and inadvertently mix up presence and absence.

o   Symptoms are a special case, where we have both the ability to use an explicit negation using the “Exclusion of a symptom” archetype, or the softer “no more than usual” “Nil significant” boolean element.

·       Some concepts aren’t as safety critical, or are more of a specific status that should be updated in one single place of the health record. An example of this is smoking status, where both “Former smoker” and “Never smoked” could be seen as negations of “Current smoker”. This is handled as a value set in the main data element of the smoking summary archetype.

·       Specific physical examinations sometimes need to be excluded, to be able to say “I didn’t perform the examination of the left eye because the patient has an artificial left eye”. This is handled using a separate cluster that’s reused within each examination cluster.

·       Specific observations or scorings sometimes need to be excluded, to be able to say “Children’s Global Assessment Scale wasn’t performed for this child, because they’re younger than 4 years old”. This is an emerging pattern, but for now it looks like it’ll be similar to the examination exclusion, using a separate cluster that’s reused between the observations. We still don’t know for sure what to call this cluster, as “Examination of observation” can easily be mixed up with the archetype class OBSERVATION.

·       There’s also the issue of how to specify the presence or non-presence of something in the context of an examination of the same thing. A good example of this is body fluids, which archetype is out for review right now. If anyone would like to have their say on this and isn’t invited to this review, please adopt this archetype to be invited: http://openehr.org/ckm/#showArchetype_1013.1.2255

I might have forgotten something, but I think these are the basic patterns of negation/exclusion we’re using/exploring as of now.

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