EMS Vocabulary Approach

EMS Vocabulary Approach

Updated May 2011 in light of guidance received from the HL7 Vocabulary Technical Committee

Ockham Information Services LLC

EMS DAM and Constrained Model Vocabulary Approach

• The standard on which the EMS DAM is founded has defined value domains for data elements. Elements that will be modeled as coded data types will be bound to vocabularies. The levels and stages at which this happens may vary among elements.

Process

1. The Domain Analysis Model will identify concept domains via property definition. It will not map them to recognized HL7 concept domains.
2. The Domain Message Information Model, or "DMIM," will bind structural vocabularies as required in order to specify the appropriate RIM classes. Domain vocabularies will not be bound at this stage.
3. Domain vocabularies will be bound in specifications, namely, the CDA Patient Care Report (a.k.a. run report).

Modeling

Some elements may have value lists that mix concepts, e.g., a 'response mode' question whose answers include whether the unit used lights and sirens, 'enhanced speeed,' or traffic light control. In these cases, we have adopted a 'lumping' approach, with two assumptions:

1. the elements have been defined in light of the best case for EMS use, including due consideration for the user's need for simplicity and speed. E.g., we do not plan to a ask a field EMT to answer three questions when the relevant information can be constructed as one question.
2. nothing in this approach those who desire more granular data from identifying constituent concepts of answers and performing analysis based on that analysis. This will not, of course, affect the information actually collected.

We do not plan to use postcoordination, expecting implementers to have limited capability for processing expressions.

Vocabulary Identification

Preferred systems are

• questions & observable entities: LOINC
• clinical concepts (patient observations & procedures): SNOMED CT
• billable condition classifications, injury causes: ICD-10
• nulls: HL7
• demographics: HL7
  • race: CDC
  • provider taxonomy: CMS
  • occupations: BLS SOC
  • industries: NAICS

Exceptions will be made in certain cases, e.g., the Glasgow Coma Scale, where SCT does not contain an answer code for a structured instrument that is fully modeled in LOINC.

Binding

Once the modeling is complete, each element can be classified in one of the following categories:

1. Match: A standard terminology system can be identified that professes to cover the concept domain, and all required values are in it.
2. Feasible Match: A standard system can be identified that professes to cover the concept domain, some required values are in it, and there is a workable submission process.
3. No Match: No standard system can be identified that professes to cover the concept domain

For the categories listed, we will propose the following:

• For category 1, use the identified system, requesting additions as necessary.
• For categories 2 & 3, submit the codes to the US National Release Center or to LOINC. Use the temporary codes assigned in the September (level 3) publication.

This triage will occur by June 15th 2011 in order to facilitate the current ballot deadlines.

Also see notes at http://wiki.hl7.org/index.php?title=EMS_DAM_Vocabulary_Approach

OIDs

EMS Vocabulary OIDs