The policies and principles used to develop the mapping from EDQM to SNOMED CT pharmaceutical dose forms are described below.

Aims and Objectives

Mapping Policy describes the guidelines that govern the map as a whole.

Aim and Objectives

The aim of the EDQM to SNOMED CT map is to To produce as close as possible to a 1..1 an exact semantic match mapping between the EDQM Pharmaceutical Dose Forms in EDQM Standard Terms as the source and the SNOMED the SNOMED CT descendants of 736542009 of 736542009 | Pharmaceutical dose form (dose form) | as targets, to support the use cases described above..

The map aims as much as possible for a 1..1 exact semantic match of the pharmaceutical dose forms. In order to achieve that aim, the semantics of each source concept and possible target concepts have been examined in detail, using all available information and ascertaining what within that information was definitional and what was to be considered either descriptional (only) or "implementation guidance" (the latter applying especially for the EDQM Standard Terms).

If, having undertaken that examination, an exact match was not possible, where appropriate within existing guidance, additional concepts were authored within SNOMED CT to support an exact match. For some individual concepts and groups of concepts (for example, those with more than one intended site), this is an ongoing process and may involve further changes within the SNOMED CT dose form content. 

Although the process for change within EDQM Standard Terms is more complex for various reasons, some recommendations for change to EDQM Standard Terms have also been made, especially when these are in accordance with recommendations from other groups working with the EDQM Dose Forms.

When studying fully specified names for SNOMED CT dose form concepts and particularly when requesting new concepts, the implications of different languages and the translation process have been considered in order to facilitate as much as possible clarity in the semantics of the domain in different languages.  However, not all the challenges are directly resolvable, especially when a particular language does not have words to distinguish between concepts with different pharmaceutical meanings (for example, some languages do not have a different word for a transdermal patch, only a word for a plaster)When an exact match is not possible, further discussions will be undertaken with the relevant parties and guidance will be offered to users of the map.  

Scope

Map source: EDQM Pharmaceutical Dose Forms (PDFs)

• Active PDFs at 2021-

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• 07-

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• 31 that are not ‘Veterinary only’
• A "snapshot" full download of EDQM PDF data was taken via the EDQM API 

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The following EDQM PDFs are considered "out of scope" since they either support types of products that are currently out of scope for the SNOMED CT medicinal product hierarchy (e.g., herbal products, blood products), or they are not PDFs within the SNOMED CT definition (e.g., the solvent terms, the living organisms).

Map target: SNOMED CT 20210731 20220731 international edition

• Active concepts that are < 736542009 | Pharmaceutical dose form (dose form) |

See also the "No Map" section below for further information about Scope and concepts that are marked as "No map".

Cardinality

The aim is to get 1..1 semantic maps wherever possible and to provide guidance in all situations where that is not the case.

"No map" codes

When an EDQM Standard Terms code is in the scope of the map but no semantically matching concept is present in SNOMED CT this is considered a "No map". A significant number of new PDF concepts have been authored in SNOMED CT to resolve this "No map" situation when it has been possible to confirm that the PDF is used to describe one or more medicinal concepts authorised in member countries. As noted in the section describing the EDQM PDFs, EDQM will categorise a dose form as for "human and veterinary use" even if it is requested for initial use with a veterinary medicinal product unless the PDF is specifically for veterinary application (e.g. "Continuous-release intraruminal device"). Therefore there are EDQM PDFs that are within the scope stated above but which have never been used to describe a medicinal product for human use.  Whilst it would be possible to author PDF concepts in SNOMED CT that are an exact match for many of these EDQM PDFs, having concepts in SNOMED CT that are not directly required to support patient care is not sensible. However, as each of these EDQM PDFs have been evaluated, they have been assigned an additional category:

• PDF concepts that SHOULD be added to SNOMED CT if requested by a member to support authoring of medicinal products.  These are PDFs whose semantics can be fully defined using the SNOMED CT PDF concept model and would be clinically useful PDFs for the use cases.
  • For all of these, a fully specified name and logical definition have been suggested.
• PDF concepts that COULD be added to SNOMED CT if requested by a member to support authoring of medicinal products. The Dose Form should have an international value for the SNOMED community. These are PDFs whose semantics are not as easy to fully define in SNOMED CT and/or for which there are some reservations as to their clinical usefulness.
  • For these, a fully specified name and logical definition have been tentatively suggested.
• PDF concepts that SHOULD NOT be added to SNOMED CT.  These are concepts with ambiguous semantics or significant reservations about their clinical usefulness.  There are very few of these, and they mostly occur from early, less rigorous requests to EDQM or to describe products that would now not be considered medicinal products. (for example, the EDQM term "implantation tablet"; any new products would be encouraged to use the term "implant").

The assignment of intended maps to these categories will be used to inform future updates of this map.

Association/Correlation and Cardinality

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The aim is for the source and target to be "equivalent" (i.e. an exact semantic match).

However, But there will be some maps that are will not be exact, but which we wish to make and to note that they . In these situations, the map will have a different association .type:

Narrower A narrower (than) map: Use this This association is used when the meaning of the SNOMED CT concept is is narrower than the  the meaning of the EDQM concept concept.

• Another way of saying this is that this is a "broad-to-narrow" map (from the EDQM source concept to S-the SNOMED CT target concept); this is a 'narrower' mapping , because you're mapping because the map is to a concept with a narrower meaning than the source concept
  
  • For example, a mapping between "
  Intravesical solution/solution for injection"
  • Medicated sponge"  in EDQM to "Conventional release
  intravesical solution
  • cutaneous sponge (dose form)" in
  S-
  • SNOMED CT is "narrower" -  as the EDQM concept
  appears to suggest two quite different methods of administration are possible
  • is very generic in terms of not specifying an intended site of administration, whereas the
  S-CT concept is specifically a solution
  • SNOMED CT concept does explicitly have an intended site of administration (cutaneous).
• Note that when 'Narrower than target' maps are made, these Some 'Narrower target' maps may be made, in situations where the EDQM concept is inappropriate for inclusion in SNOMED CT but alternative more granular concepts are available.  These may give a 1..* cardinality between an EDQM concept and SNOMED CT concepts, especially when the mapping is considered in its entirety.

Broader A broader (than) map: Use this This association is used when the meaning of the SNOMED CT concept is is broader than the  the meaning of the EDQM concept, and it is not possible or considered reasonable to author new, more granular SNOMED CT concepts

• Another way of saying this is that this is a "narrow-to-broad" map (from the EDQM source concept to S-the SNOMED CT target concept); this is a 'broader' mapping , because you're mapping because the map is to a concept with a broader meaning than the source concept
  
  • For example, a mapping
  between
  • between  "
  Capsule
  • Inhalation powder,
  soft
  • hard capsule"
   
  • in EDQM to "Conventional release
  oral capsule
  • powder for inhalation (dose form)" in
  S-
  • SNOMED_CT is "broader" - as
  the S-CT concept encompasses both hard and soft capsule types
  • the EDQM concept is precise, particularly in regard to the encapsulation of the dose form whereas the SNOMED CT concept is less explicit, with no description of encapsulation of the inhalation powder.
• Note that when "'Broader than Some 'Broader target’ maps may be made; these are likely to may give a *..1 cardinality when the mapping is considered in its entirety.

In all cases where the final mapping is 'Broader target’ than’ or 'Narrower targetthan', implementation guidance will be provided.

Principles

Mapping to a Semantic Match

The map was developed, based on the principle that the source and target codes of 'equivalent' maps must be an exact semantic match.

For more information on the semantic representation of codes in the source and target terminologies please refer to 3.1 Comparison of Dose Form Semantics.

Transform Dose Forms

As a general principle. if there is a PDF that undergoes a transform to another PDF (e.g. "Powder for intravesical solution") whose transformed dose form (the administrable dose form) would be "Intravesical solution", the transformed PDF concept should be available in SNOMED CT International content even if there are no CDs that directly require it.  Some extensions may model "administrable CDs" or equivalent concepts and require the administrable dose form.

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is provided.