Thursday, July 21, 2011

The Evolution of a Problem and its Solution

One of the well received pieces of feedback on the IHE Reconciliation profile this week was about the maintenance of identifiers for information items produced as a result of a reconciliation process.  Essentially, if you incorporate a fact about a patient into your EHR that was externally sourced, you have to retain and reproduce the identifier you originally recieved with it.  We had made that a strong recommendation, but due to feedback, changed that to a requirement.

As a result, we needed to address another issue, which is how information evolves over time, and how its identity changes over time as well.

There are a number of interesting cases:
  1. Status Updates
  2. Changes in Treatment 
  3. Additions of new Information and relationships 
  4. Correction of Erroneous Information
  5. Disease Progression 
  6. Changes in Diagnosis
Status Updates
Status updates do NOT change the identity of an act that has been recorded.  Over time, order #### has been placed, shipped, canceled, received, paid et cetera.  Over time, diseases are active and resolved, treatments (e.g., medications) are active, completed, canceled or discontinued.  Et cetera.  If during the reconciliation process, you make a status change, it does not change the original identity of the item.   

Changes in Treatment
Medication X is discontinued, replaced by medication Y, or is used in a different dose and/or frequency are examples of this case.  In this case, the Status of the old medication is changed (to completed or , and a new medication information item is created with a new identity.  The status of the old item is changed to reflect the reason kind of change made.

If a medication was discontinued without replacement before it was expected to be finished normally, it would be marked as "aborted".  Marking an act as "aborted" is a cue that the act was terminated abnormally without any replacement.

If it was discontinued without replacement before it was expected to be finished normally, and a new medication replaces it, it should be marked as "obsolete".  The new information item can be marked as the previous acts replacement.  If dose or frequency are changed, it should be treated the same way.  Marking an act as obsolete is a cue that that you should look for a replacement.

If the medication completed normally (e.g., a three month prescription), and its replacement is different (in medication or dose), then it should be marked as completed, and the new information item with a new identity can be linked as its successor. 

This old piece of data was incorrectly recorded, and a new piece of data replaces it.  Again, pretty easy.  In this case, the old information item has its status changed to "nullified", indicating that it was incorrect, and the new information item has a new identity, and can be marked as the replacement for the old one.  This kind of correction only applies when there have been mistakes in entry or reporting of the information, NOT when there have been mistakes in judgement (see changes in diagnosis below).

Let's say that you have an allergy with a known manifestation of hives.  Subsequently, it is determined that a new manifestation exists that is anaphylaxis.  The new manifestation has a new identity, but is attached to the old allergy and the identity of the old allergy does not change.  Similarly, you can have an assessment of the severity of a particular disease.  The assessment may change over time.  Each time it changes, it takes on a new identity, but the original observation to which it applies does not change its identity.

The addition of descriptive attributes previously unknown (e.g., a stop date), also would not change the identity of an information item.

Progression of Disease
Influenza can eventually result if not treated into pneumonia.  This is a natural progression of disease along a particular pathway.  In this particular case, the progression to pneumonia is a new observation on the patient with a new identity, and the previous observation can be retained as well with its existing identity, because both are true. Note, in this case, the "concern" act from which the influenza observation originated would have a new observation associated with it for the pneumonia.  The identity of the original concern does not change. There are cases where the diagnostic categories form a progression that excludes the previous category (e.g., Stage I Cancer vs. Stage 2 Cancer).  In these cases, the original observation

Changes in Diagnosis
This is the stickiest one to deal with.  A change in diagnosis is a new judgement, clearly, and that has a new identity.  However, I'm not sure what to do with the old one.  If the previously recorded diagnosis of X was made as the result of a clinical judgement, and it is incorrect, the following things are true statements:

  • A previous diagnosis was made that the patient had X.
  • That diagnosis was incorrect.
I think the right way to handle this one is that same as if you decide to change the treatment for a patient.  The old diagnosis is marked as "aborted" (NOT nullified).  

My reasoning is this:  The old diagnosis (or assessment) did exist.  Marking it as "aborted" indicates that the line of reasoning was prematurely terminated (e.g., in light of new information).  If instead, it had been marked as nullified, it would have indicated that the diagnosis was reported or entered incorrectly, which is in fact, NOT the case.  It may very well have been reported and entered correctly, but was made based on incomplete or incorrect information.  When a diagnosis is changed in this way, it indicates that the providers judgement has changed, and follows the recording pattern whether that judgement is about the condition the patient is suffering from, or the treatment they are given.

This doesn't solve every issue.  One thing I'm still struggling with is how to deal with "holds" or temporary suspensions of medications.  I believe the right way to handle this is to report every suspension event along side the medication event.  I think of suspensions to be a new event (an override of a previous decision based on temporary factors).  Reporting both allows the receiving provider to be aware that a patient is NOT currently taking their medications (e.g., due to a pending surgery).  However, I think what we need to do with this particular issue is call it out as being something that needs a profile without addressing it in the reconciliation profile.


  1. Keith, I have a couple of questions.

    Are the terms obsolete, aborted, nullified, etc. part of the standard, or are they under consideration?

    Regarding meds, are you going to ask physicians to select aborted or obsolete when they attempt to discontinue or stop a medication? And will they have to tie a new med to the one they discontinued in order to create the replacement relationship?
    Of course it is possible to replace one med with two or more, or two meds with one, is this allowed in this structure?

    You also use the term aborted for changing a diagnosis which is a pretty common occurrence. Are the terms aborted, obsolete and nullified expected to show on the screen, or is this just a behind the scenes translation of more intuitive terminology for clinicians? (for example discontinued for aborted and changed for obsolete - changing, stopping and discontinuing meds are commonly used terms and I think changed could also work for changing a diagnosis).

  2. Good questions Margalit. The terms I'm using "obsolete", "aborted", "nullified" are already part of the standard. How they get reflected on screen is up to the implementor, and I agree, we should use the terms the clinicians use for that.

  3. Hi Keith,
    You are getting into some very interesting territory here! I’ll tackle a couple of points you raise.
    I caution you to use the word 'status' to refer both to actions being done/complete and for the states of abstract concepts such as a diagnosis. Semantically and in practice they are very different.
    In fact, so much so that in openEHR archetype there is a specific class to manage the action state of an order or instruction. The openEHR state machine in the reference model recognises the following states: Initial; Postponed; Cancelled; Scheduled; Active; Suspended; Aborted; and Completed.
    For each of these states, clinicians can determine in archetypes what are the clinical activities that need data recorded against them to track the state of an order from initiation through to completion. In the example of a Medication order/instruction -
    - Initial – record the Medication as planned
    - Postpone – the plan to order the medication has been postponed (eg admitted to hospital) (temporary, the instruction has been never been active)
    - Cancelled – the planned medication has been cancelled prior to any administration (permanent, the instruction has been never been active)
    - Scheduled - schedule/set a medication start date
    - Active – Issue a prescription
    - Active – Dispense a medication
    - Active – Commence medication/First dose
    - Active – Review medication
    - Active – Administer medication
    - Active – Withhold medication
    - Suspended – Suspend medication (temporary, the instruction has been active)
    - Aborted – Cease administration (permanent, the instruction has been active)
    - Aborted – Change dose or timing
    - Completed – Complete course of medication
    I don’t quite understand the usefulness of obsolete – it really is just an aborted medication order just like any other, the only difference is that you are trying imply a subsequent intent to replace it, and that is somewhat confusing to me – the intent to replace might not be known as the med is aborted.
    Changes in treatment:
    In the real clinical world, the clinician removes the medication from their medication list, possibly with a reason for cessation and prescribes another medication from scratch. In the openEHR archetype all 3 examples - stopping and not starting another med; stopping and starting another; and significant change in either dose or timing - warrant the recording of data points against the applicable clinically-defined pathway step in the Aborted state for the current order – in this example above, either ‘Cease Administration’ or ‘Change Dose or Timing’. Then, if another drug is ordered or a new dose/timing is ordered, a new medication order is created
    Corrections: openEHR would likely record that this current medication order had been cancelled (ie prior to the order becoming active ie administration), and issue a new order.
    In addition, status qualifiers for Diagnosis are potentially very tricky – provisional/working/final; admission/discharge; active/inactive/resolved; primary/secondary etc etc. The additional step of providing a status can add ambiguity and relies on potentially unreliable clinician input and updating/maintenance.
    Many of these qualifiers are only applicable for a specific clinician, in a particular context, for a particular period of time or a single clinical document. Persisting statuses in data, especially a shared health record or summary can become very problematic, and potentially even a safety issue. I have recorded some thoughts about this in a previous blog post -

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  5. Thoughtful analysis, Keith. In my view, not relevant to HOW physicians document the changes but how it is interpreted and stored in a structured way. Should be possible to work with physicians narrative documentation and record the statuses automatically with NLP. :)

  6. Sorry Heather, your comments got caught by the spam filter. I freed them today, but since the first seemed to cover more detail but otherwise duplicate the second, I simply deleted it. If you want the second one back, just let me know, it's not gone forever yet.

  7. Hi Keith,

    Heather has nicely set out the openEHR approach but I am not sure I wholly agree with some details.

    In UK GP systems and derived emergency summaries, it is common to display recently inactivated or expired medications (e.g last 6 months) , particularly repeat meds, which give helpful background. So I think there is merit in an obsolete/inactive status.

    I am also not wholly convinced that we can discount local/temporary status qualifiers, just because they do not have longitudinal value, or worse still may cause confusion. They may well have important semantic value, albeit only within a limited clinical event or context, particularly at at handover.

    Disentagling this is not going to be easy but will be crucial to the safe transfer of information between providers, maximising automatic transfer, whilst understanding the limitations Heather described.