Per the process described here, the following letter should be used for initial engagement of the code system owner
To Whom It May Concern
Greetings from the Terminology Authority group in Health Level Seven International (HL7).
As the owner or administrator of the <INSERT NAME OF CODING SYSTEM WHICH A SYSTEM URL IS REQUIRED FOR>, we are reaching out to you and your organisation and requesting your support. Before we get to the request itself, we would like to provide some background.
Health Level Seven International (HL7)
HL7 is a not-for-profit, ANSI-accredited standards developing organization dedicated to providing a comprehensive framework and related standards for the exchange, integration, sharing, and retrieval of electronic health information that supports clinical practice and the management, delivery and evaluation of health services. HL7 has been around for over 30 years and is supported by individual and organisational members from over 50 countries. You can find more information about HL7 and its mission at the following link: https://www.hl7.org/about/index.cfm on the HL7 website.
HL7 Terminology Authority (HTA)
The HTA is a governance committee within HL7 which works to ensure harmony in the use of coding systems from organisations outside of HL7 in HL7 standards. One of our primary purposes is, that, when the need arises for HL7 standards to use some or all of the content from the external coding system, the HTA works to ensure that both the content and its conditions of use are well understood. HTA then to liaises with the organisations who maintain them (such as yours) on behalf of HL7 or its standards development projects and teams. You can find out more about the HTA and its role at the following link: https://www.hl7.org/Special/committees/termauth/overview.cfm on the HL7 website.
Fast Healthcare Interoperability Resources (FHIR, pronounced 'fire')
Through its standards, HL7 has achieved success in making clinical and other healthcare-related software applications interoperable (able to share data with no loss in meaning) to enable more effective healthcare and consequently better patient outcomes. In recent years, the FHIR specification (and its underpinning community of standards developers, designers, and software developers) has played been a significant part in this success with the standard seeing broad adoption in the USA and internationally. This has opened the door to new, previously inconceivable, solutions being developed such as the ability for mobile devices to obtain healthcare records from hospitals. Further, the growth and adoption of FHIR has been unusually fast (pardon the pun) for an international healthcare technical standard. You can find out more about the FHIR standard at this link:https://www.hl7.org/fhir/ on the HL7 website.
FHIR and coding systems
The FHIR standard supports the ability to represent codes from coding systems such as <INSERT CODING SYSTEM WHICH A SYSTEM URL IS REQUIRED FOR> as values in structured data which may then be processes or shared. For example, the code for an diagnoses can be included in FHIR data. Without getting too technical, in order to represent codes using the FHIR standard, the following key components of information are required:
- an identifier for the code; this is usually a sequence of alphabetic and/or numeric characters e.g. <INSERT EXAMPLE CODE FROM CODING SYSTEM WHICH A SYSTEM URL IS REQUIRED FOR> from your coding system.
- a system Uniform Resource Locator (URL) which asserts the coding system which the code comes from. URL is quite a technical sounding idea, but in fact they are used quite ubiquitously including the address of web sites e.g. "http://www.hl7.org" is a URL. When URLs are used in this way (to assert a coding system), they are referred to as "System URL" values for the coding system.
- the version of the coding system which the code comes from. This may be an optional component, but it is often a good idea to include it to unambiguously communication which version of the coding system was in use.
With the increased adoption of FHIR, the HTA is often called upon when HL7 standards developers identify the need to adopt an external coding system and requires a System URL. Ideally, the System URL is endorsed for use by the coding system owner or maintainer.
So, with the background covered, lets dive into our request. In short, HL7 has identified the need to use codes from <INSERT NAME OF CODING SYSTEM WHICH A SYSTEM URL IS REQUIRED FOR> in one of its standards or solutions. Accordingly, we would like to request your participation in a process which would lead to us clearly establishing the following:
- The correct way to assert codes (or identifiers) for <INSERT NAME OF CODING SYSTEM WHICH A SYSTEM URL IS REQUIRED FOR> in FHIR
- A System URL to use in the FHIR standard to represent <INSERT NAME OF CODING SYSTEM WHICH A SYSTEM URL IS REQUIRED FOR>
- The correct way to assert versions of <INSERT NAME OF CODING SYSTEM WHICH A SYSTEM URL IS REQUIRED FOR> in FHIR
which your organisation endorses. The HTA team is very experienced in this area and has assisted many organisations with varying technical expertise to achieve the above outcome. Accordingly, we are very happy to assist you in the process including doing all the work short of the final endorsement by your organisation.
If you could please respond by <INSERT DEADLINE DATE>, it would be very much appreciated. While we strongly encourage you to participate in this process and sincerely hope that you will, we also think it is worth letting you know the outcomes which would arise from non-participation.
- First and foremost, this would leave healthcare standards and solution developers without means to use codes from your coding system in a consistent manner. In particular, it could lead standards and specification authors to independently allocate their own System URL, leading to multiple solutions to the same problem, none of which is endorsed by the coding system owner (yourself). This then escalates to implementers adopting the various approaches in their software which, in turn, results in healthcare applications which are not interoperable without extra work being undertaken. A side effect of this is that implementers may eventually decide to use other coding systems which do have owner endorsed System URLs instead of <INSERT NAME OF CODING SYSTEM WHICH A SYSTEM URL IS REQUIRED FOR>.
- To minimise the extent of the interoperability challenges within HL7, the HTA will allocate a single System URL and the correct way to assert codes and versions for your coding system. The default format for the URL is "http://terminology.hl7.org/codesystem/_____". These will then be published in HL7 standards and technical specifications.
In closing, we anticipate you may have questions in relation to this letter and wish to assure you that the HTA would be more than happy to answer them and we encourage you to reach out to us. We have regular teleconferences and can arrange special meetings with you and your team to help you better understand our request, or to start the process.
We look forward to hearing from you soon.
HL7 Terminology Authority
- Reuben Daniels **consider inserting a technical appendix of each of the above bullet points for a mature codesystem like LOINC**)