HL7 Terminology Authority

HL7 Terminology Authority

HL7 Terminology Authority


The Terminology Authority is required to support the MOU between IHTSDO and HL7 and will be relevant to HL7's relationships with other terminology development organizations. The HL7 Terminology Authority (HTA) will be concerned with the creation, implementation and management of HL7 processes for external terminology management. These processes will be informed by input from the existing Vocabulary workgroup and existing terminology practices within HL7. The activities of the Terminology Authority are intended to complement existing Harmonization procedures.

Purpose for an HL7 Terminology Authority

As a representative body of HL7 International (HL7), it is the purpose of the Terminology Authority to ensure that HL7 provides timely and high quality terminology products and services to meet its business needs. Additionally, the authority provides a single point of communication with external terminology standard development organizations (SDOs) with which HL7 has established formal relationships.


The Terminology Authority is exclusively concerned with the content of Value Set Expansions that are derived from external terminology Standards Development Organization code systems. The scope of responsibility of the HL7 Terminology Authority includes:

  1. Development and maintenance of HL7 quality processes and measures related to HL7 terminology derived from external terminology SDOs.
  2. Provide advice, where needed, on the acceptability of vocabulary proposed for inclusion in HL7 vocabulary ( NOT "infrastructure controlling" vocabulary, e.g. CS data type) .
  3. Maintains relationships with external terminology providers to ensure legal use of their products.
Relationship of Terminology Authority to the Technical Steering Committee (TSC)

The HTA will work with the TSC to implement any process or policy changes that impact the Working Group (see GOM definition of the Working Group).

Relationship of Terminology Authority to existing Harmonization processes

The Terminology Authority serves in an advisory capacity to the existing harmonization process. All final terminology decisions are made as part of the harmonization process. In response to requests for new coded content, vocabulary facilitators may submit vocabulary harmonization requests to the Terminology Authority for review as to their content coverage by external terminology systems. If deemed appropriate for derivation from or addition to an existing external terminology, the Terminology Authority will recommend that the proposal be revised to address the use of the external code system. If the recommendation is accepted, a revised vocabulary proposal will be developed and submitted to the Harmonization process and the Terminology Authority will manage any content change requests to the external terminology system maintainers.

The Terminology Authority may become involved in the Harmonization process at the following points:

  1. During vocabulary proposal development - The vocabulary facilitators should decide during the development of a vocabulary proposal whether the concepts that would result from the value set expansion of a value set definition may be drawn from an external terminology and whether all of the concepts needed to support the proposal are currently present in the terminology. The Terminology Authority should review these types of proposals prior to submission
  2. During harmonization - A Terminology Authority representative should: participate as a voting member during Harmonization where proposals for external terminologies are being considered; be prepared to answer any question that arise concerning the use of external terminologies; and have "Harmonization steward" status for proposals to be implemented in external terminologies. Harmonization may assign content requests to external terminologies to the Terminology Authority during the meeting.
  3. Following harmonization - The Terminology Authority reviews the results of the Harmonization process for action items assigned to it. New content is created and assigned identifiers are returned to Harmonization if necessary.

Draft Policy and Procedures

HL7 Terminology Authority: Policies and Procedures


This document outlines the formation of an HL7 Terminology Authority and the policies and procedures under which it operates.


A call for nominations to the HTA will be distributed by the HL7 Chief Technical Officer (CTO). Nominations may be made by any HL7 member in good standing and self-nomination is allowed. The CTO will make recommendations to the Board regarding the composition of the HTA, based on these nominations and other considerations.


The HL7 Terminology Authority (HTA) shall be composed of five individuals that shall be selected from the current HL7 membership and who possess the skills, expertise and experience described below. The HTA members, who shall be appointed to the Authority by the HL7 Board from the slate of nominees, shall include at least two members of HL7 International Affiliates and one co-chair from the Vocabulary Work Group. The Board shall ensure that appointments to the HTA are consistent with the goals and objectives currently defined for the HTA and best serve the interests and responsibilities of HL7.


The members of the HTA shall select from amongst themselves a Chair, and a Vice Chair who shall conduct the business of the HTA in the Chair's absence. The HTA shall select its chair following the HL7 Plenary meeting in odd-numbered years from among members. The selected member shall take office in January of the following even numbered year.

Criteria for membership

Candidates for membership of the HTA must recognize the importance of, and have a commitment to, the appropriate development and use of terminology as a critical success factor for HL7. They must be current members of HL7 or an HL7 Affiliate with strong written and verbal communication skills and expertise in at least one, and preferably all, of the following areas:

  1. Large scale or enterprise-level development or management of terminology with a focus on achieving working/semantic interoperability between data exchange stakeholders in both intra- and inter-enterprise contexts.
  2. Good terminology practices as specified by the Cimino desiderata[1] and knowledge of the HL7 core principles for terminology.
  3. The design and use of one or more large reference terminologies commonly used in the healthcare domain. (e.g. SNOMED CT, LOINC, ICD-10, etc.)
  4. The implications of developing and managing an extension to one or more of the reference terminologies cited above.

Candidates shall provide documentation of support for their participation on the HTA from their employers or a like statement of their personal commitment if individual members of HL7. Members of the HTA are expected to:

  1. participate in 75% of scheduled conference calls
  2. dedicate up to 2 hours each week around the time of harmonization, in addition to conference calls, to HTA deliverables
  3. physical attendance at a minimum of two of the three Working Group Meetings each year
Trial Participation

Candidates wishing to be considered for membership on the HTA may be expected or invited to participate in HTA discussions as non-voting individuals prior to becoming a member to ensure their ability to meet the expected commitments and demonstrate the appropriate qualifications. This will allow ‘new’ HL7 members to fully participate in the HTA and contribute to the work as they become more fully informed as to the duties and requirements of HTA membership.

Term of Service

The HTA Chair and Vice-Chair will be appointed for staggered two-year terms to ensure continuity of committee knowledge and ongoing goals and objectives of the HTA.

Terminology Authority Chair and Vice-Chair

The terms of service for the HTA Chair and Vice-Chair will be the same as for the regular membership

Other members

For the regular members of the HTA, the appointees will serve staggered terms with two positions open in odd numbered years and three positions open in even numbered years. Members are eligible for reappointment of up to two additional terms. Prior members of the authority may be reappointed after a hiatus of one two year term.

Notification of Renewal

The Board shall provide two months notice to the HL7 membership and HL7 Affiliates when members are subject to reappointment or proposed new member appointments are being considered for positions on the HTA. Comments regarding the appointments may be submitted during this period for consideration by the Board prior to making the final appointments to the HTA.

Change of Member Employment Status

Should a member of the HTA experience a change in employment status, the Board reserves the right to seek the member’s resignation from the HTA based on real or perceived “preponderance of influence” or any other concerns as expressed by the other members of the HTA or the Board; e.g. change of the HTA member’s focus or priorities with respect to HL7 as expressed or demonstrated by the member’s new employer or contract holder.

Removal of Member

Any HTA member who, in the opinion of the HTA Chair or Vice Chair, is unable to satisfy the expected commitment based on both meeting attendance records and general effectiveness of participation may, with approval by the Board, be removed from the HTA at any point during their term.

Replacement of Member

Should an HTA member resign or be removed from the HTA, the HL7 CTO shall make a recommendation to the Board for a replacement. With the Board’s approval, the replacement HTA member will serve the remainder of the term of the person they replace.

Conduct of Meetings

All HTA meetings shall be open to any interested party. Minutes shall be taken at all meetings and posted on the HTA wiki. HL7 and the SDO community in general are free to comment, criticize, or raise additional issues.

Conflicts of Interest

Each member will be obligated to fully and fairly disclose to the HL7 Board Chair any real or potential conflict of interest the member has or may have with respect to any matter or item being considered, discussed or addressed by the Committee. In the case of such a conflict, the member must recuse themselves from both the discussion and subsequent vote on the item.


The key activities of the HL7 Terminology Authority includes:

  1. providing recommendations to the HL7 Vocabulary Working Group on external terminology product and service developments.
  2. providing expertise during the development of HL7 terminology products and services.
  3. supporting harmonious and effective collaboration by HL7 with international terminology standards development organizations (e.g. ISO, WHO FIC, IHTSDO, LOINC, etc.).
  4. in conjunction with the TSC and those work groups the TSC identifies, such as MnM, Tooling and Vocabulary WGs, develop quality assurance guidelines for submission of vocabulary requests to external terminology development organizations.
  5. determination of whether specific terminology content should be maintained internal or external to HL7 terminology.
  6. identification of potential IP restrictions (existence of MOUs or agreements)
  7. define minimum quality levels for terminology submissions to external terminology development organizations.
  8. Define the policies and procedures...(from minutes)
  9. Develop procedures to ensure the fitness for purpose and usability of external SDO approved vocabulary value sets.
  10. Make recommendations to the TSC and any additional work groups identified by the TSC such as the HL7 Vocabulary Work Group on external SDO issues and policies related to terminology use in HL7 artifact.
  11. Manage HL7 submissions to external terminology SDOs.
  12. Develop inclusion and exclusion criteria for HL7 managed extensions to international terminologies.


Resolutions and recommendations from the HL7 Terminology Authority shall be determined by a simple majority vote cast at a meeting which there is a quorum. If the chair of meeting has voting status, the chairs vote will be included. A quorum of the Committee consists of 60 percent of its members present at each meeting either physically or virtually. A valid vote is achieved when the following conditions are met:

  1. A quorum of voting members is present
  2. A simple majority is reached

In the case of a tie vote or the vote is not valid, the item will be tabled for consideration at another meeting.

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