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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.