(registered 2020-11-23, last updated 2020-11-23)

Media type name: application

Media subtype name: elm+json

Required parameters: N/A

Optional parameters:

   charset - if present, this must have the value "UTF-8"

Encoding considerations: binary

Security considerations: Expression Logical Model (ELM) is a 
   machine-readable translation of a library of Clinical Quality 
   Language (CQL). It is a semantically verified representation aimed
   at supporting translation to or direct execution of the logic 
   represented by the CQL. It is analogous to a shareable 
   representation of a query plan in database management systems, or 
   an intermediate language such as MSIL or Java bytecode.

   For systems that are capable of evaluating ELM content directly, 
   the language itself is pure-functional with specific limitations 
   that prevent generalized recursion. However, ELM is a data access 
   language similar to SQL, and is capable of expressing queries that
   result in large amounts of data. Execution environments SHOULD 
   provide facilities to limit the potential for denial-of-service 
   attacks.

   In addition, the language has facilities for referencing logic 
   defined in external libraries; systems that support this 
   capability SHOULD ensure that security concerns related to running
   general code can be appropriately addressed.

   The language is designed for and used in healthcare settings. As 
   such, appropriate precautions for protecting patient safety and 
   privacy SHALL be considered. In particular, the language supports 
   mechanisms for tracing and logging of intermediate expression 
   results; mechanisms for ensuring appropriate use of and exposure 
   to patient data SHALL be provided.

Interoperability considerations: Expression Logical Model (ELM) is 
   designed to enable platform- and model-independent sharing of 
   logic in the healthcare domain. The specification separates the 
   representation of logic from the representation of the data model 
   on which it operates, as well as the terminology used to specify 
   any concepts referenced by the logic. Libraries of ELM specify the
   model on which they operate, and systems that evaluate ELM for 
   specific models must be capable of providing data access in the 
   model expected by the ELM. The specification should be consulted 
   for more details on interoperability considerations when 
   exchanging ELM.

Published specification:

   https://cql.hl7.org/07-physicalrepresentation.html#media-types-and-namespaces

Applications which use this media: Healthcare applications that deal 
   with clinical quality and public health reporting, clinical 
   decision support, and clinical research and registries. 
   Applications range from implementation guides that use CQL to 
   share unambiguous descriptions of queries and logic, to decision 
   support services and quality reporting systems that either 
   translate or directly evaluate the ELM.

Fragment identifier considerations: N/A

Restrictions on usage: N/A

Additional information:

   1. Deprecated alias names for this type: N/A
   2. Magic number(s): N/A
   3. File extension(s): N/A
   4. Macintosh file type code: N/A
   5. Object Identifiers: N/A

General Comments: N/A

Person to contact for further information:

   1. Name: Bryn Rhodes
   2. Email: bryn&dynamiccontentgroup.com

Intended usage: Common

   Used for exchange of knowledge and logic in healthcare-related 
   applications.

Author/Change controller: Health Level Seven International (HL7) 
   (http://hl7.org)