The eCQM Governance Group reviewed the issue in November 2018 and agreed with a transition to use SNOMED-CT Substance Class for allergy class in eCQMs. To support the transition, the QDM User Group (December 19, 2018) noted:

Claudia Hall (Mathematica) - Noted for the upcoming Annual Update, two measures will pilot this approach. 

Lisa Anderson (TJC) - Noted there is a one-year transition period.  For the next annual update cycle, they are adding a value set that represents medication as a class in addition to the current value set.  Will do this for one year and then solicit feedback from implementers to determine if the next cycle is a good time to remove the previous value set.  This allows those on RxNorm to continue using it next year.

No further action is required from the QDM User Group.

The QDM User Group met on October 17, 2018. Following is a summary of the discussion:

To indicate an allergy instead of listing large value set, there is a desire to say allergic to a class of drug. [Reference the presentation provided by Rob McClure within this Jira Ticket.]

Drug class is a grouper, i.e., a way to combine together medications that have some commonality, such a grouper is not a real thing.

Drug classes have two primary uses, to provide:

1. An alternate choice list (i.e., group a series of things useful in context of making a choice). As an example, drug classes are useful in providing a list of therapeutic alternatives (e.g., analgesics).
2. A group of substances that is cross-reactive (e.g., with respect to allergies).

These two uses do not reliably result in the same member list. True cross reactivity is a fairly illusive goal.

Drug classes need to be captured in patient records. For example, the patient reports that, “I’m allergic to penicillin.” This information can be captured as text or as encoded data. We encode to link the class object to actual orderables. Mapping to an orderable list is a good deal of work. Orderable list inconsistency can cause harm.

Drug class code system requirements:

• Includes concepts we need
• Is universally available
• Is low cost
• Provides acceptable, vetted, maintained sets of grouped members (member list is easy to get)
• Provides links for members to orderables

Code System Options:

• NDF-RT
• Multiple class-type representations
• Class concepts not maintained
• Now gone

• Med-RT
• Made up of its own concepts (from NDF-RT)
• Took an academic approach and it asserts relationships between other code systems in addition to its own concepts.
• MeSH represents chemical structures (penicillin, opioids)
• Difficult to use because member hierarchy is hard to retrieve.

• Anatomic Therapeutic and Chemical (ATC)
• From World Health Organization (WHO)
• Used worldwide
• Used for drug utilization monitoring and research
• Strong reluctance by WHO to make changes in this structure when it results in drug consumption changes

• RXNorm
• No class hierarchy

• SNOMED CT
• New focus on improving the drug domain
• Linkage to MED-RT, RxNorm

Suggested approach

• SNOMED CT (substance hierarchy, not product hierarchy) as it has the best coverage.
• Transition to MED-RT once usability and completeness issues improve

Next Steps

This proposal requires review and approval by the eCQM Governance Group before implementation. Review by the Governance Group should occur in the next several weeks.

QDM User Group medication class presentation uploaded to this Jira ticket - discussion on 17 October 2018.

Due to availability of experts and preference to review options at the upcoming HL7 Plenary and Working Group Meeting in Baltimore (Oct 1-5, 2018), the topic is deferred to the October 17, 2018 QDM User Group.

Rescheduled for September 26, 2018 UG meeting

Lisa,

Thank you for checking in.  I had hoped to bring this up on the June 2018 QDM User Group meeting but Rob McClure will not be available.  We will discuss on the July User Group meeting.

 Hi Floyd-  I am just following up on this to see if there has been a final resolution from the eCQM Governance group, since it has been a few months.

This issue was discussed on the Governance Committee today (January 23, 2018). MED-RT should be available by the end of 1st quarter, 2018. Therefore, MED-RT may be the preferred code system for drug class. ONC noted that the 2018 ISA indicated the use of SNOMED CT for drug class because the timing for MED-RT was not know, but that the ISA recommendation will be updated once MED-RT is available. The Governance Committee also will seek feedback on the issue regarding which body has the authority to make a decision on changes in terminology recommendations. For the present, any changes would not impact measures to be published in 2018 and implemented in 2019. Any changes will impact measures prepared for publication in 2019 and implementation in 2020. Will await a decision of the Governance Committee and inform the QDM User Group.

The QDM User Group discussed this issue on the January 17, 2018 call.
Historically, prior to the 2018 ISA, National Drug File - Reference Terminology (NDF-RT™) was always recommended to express medication classes. The Value Set Authority Center (VSAC) did not have NDF-RT™ as a separate code system until this past year; thus it was not available for quality measures. NDF-RT™ is now available and could be used as a code system with concepts that could represent a statin as a medication class. Whatever code system used should have a consistent association with a set of ingredient concepts. SNOMED CT has the accurate list of ingredients.
NDF-RT™ will be incorporated into a new code system which will be released soon: Medication Reference Terminology (MED-RT™). MED-RT™ will replace NDF-RT™. When published, MED-RT™ will have direct links to the SNOMED CT concept as well as the RxNorm concepts. Using SNOMED CT in the near term does not preclude using terminology services to address future concepts, specifically MED-RT™. However, MED-RT™ might be a better choice because it actively links a set of vetted ingredients to the class concepts.
SNOMED CT is widely used internationally. The U.S. is not planning on using SNOMED CT to manage its representation of drugs. The intent is to continue to use RxNorm as a way of representing drugs within the U.S. jurisdiction.
Measure developers suggested that a decision on whether to use SNOMED CT or MED-RT may depend on the timing of MED-RT availability. ESAC also noted that recommendations for code system usage has previously come from the HIT Standards Committee Vocabulary Task Force which no longer exists. The issue was placed on the agenda of the Governance Committee for January 23, 2018 for discussion.

Adding SNOMED product class assumes that:
1) All implementers will have the resources to purchase drug information vendor (DI) technology and implement it.
2) All DI vendors will include a mapping from their internal terminology to SCT drug class concepts.
3) All DI vendors will seek to have a consistent and openly verifiable linkage between the internal concept used to represent the SCT drug class to something consistent with orderable drugs, based on drug ingredient.

Schedule UG discussion regarding use of SNOMED-CT product hierarchy codes included with RxNorm ingredient codes.