In order to understand how a medication concept can be appropriately leveraged, you need to understand its characteristics and which are required to support a particular activity.
For the purposes of this primer, the term ‘medication concept' covers any entity that represents a medication from the ingredient to the physical packaged product. This excludes therapeutic classes, allergy classes and other taxonomies that may be used to group or relate medication concepts. This also excludes a medication order, which is an orchestration of a medication concept with other contextual information (we will talk more about this in a later post...).
The following diagram depicts the Medication Concepts Continuum. It is intended to provide a ‘cheat sheet' that can be referred to throughout the rest of this lesson. The characteristic breakdown in this diagram are generalizations and, as such, do not represent the actual structure of any existing drug vocabulary vendor. To interpret how a particular vendors structure fits into this model, please refer to your vocabulary vendor's documentation.
A medication concept falls into one of three generalizations: Abstract, Dispensable or Actual.
The concepts in the Actual generalization represent things that physically exist in the real world. You can actually put your hands on one. A tablet or bottle of tablets, for example, is an actual medication concept.
The concepts in the Dispensable generalization represent things that can be conceptually dispensed and administered to a patient. Another way to think of them is that they represent a completed notion of a medication. In other words, if I have a dispensable concept I have sufficient information to select a specific actual concept off of the shelf.
The concepts in the Abstract generalization (which is most of them) represent primitive characteristic concepts or an incomplete combination of characteristics. This type of concept is typically created to function as a navigation pivot OR a an anchor for additional information. An example of a multi-characteristic abstract concept would be ‘warfarin sodium tablet' (Ingredient + dose form), which is not sufficient to identify an actual physical entity, but it conveys and idea of an ingredient and whether or not it will affect the patient systemically.
The Davinci Code(s)
When you look at the continuum you will also notice that there is the central inverted pyramid (not unlike the La Pyramide Inversée in front of the Louvre) that represents the continuum of medication concepts. These are the codes that drive order entry, prescribing, alert checking and med-reconciliation.
On the right side there is a collection of other concepts. These other concepts are primitives.
You can think of the primitives as the raw building blocks that, when combined, establish the medication concepts that we find in the continuum. Examples of a primitive would be ‘route of administration', ‘dosage form' and ‘unit of measure'. For obvious reasons, these are critical to the meaning and stability of the medication concepts. We cover them in more detail in a future post.
When you examine a drug concept it is important to note where it plugs into the continuum. In many ways, that will give you an idea as to what you can actually do with it:
- To dispense a medication you need a dispensable
- To determine if a medication systemically affects the patient you need dose form and/or implied route
- To properly validate the dose you need to know the period of release
- To determine the inactive ingredients in a medication you need to know who manufactured it
- To be able to scan it with a bar code reader you may need to know its packaging details.
You may think it sound straight forward, but I have seen attempts to use the wrong concept for the wrong purpose and, like trying to make fruit smoothie with a chipper shredder... it did not end well.
The next topic will be how medication ingredients are typically represented and why it is not always as straightforward as it seems.