What are the Types/Classifications of Templates?

HL7 Templates can be classifies differently according to the roles that they play in the constraint process. Below are some ideas and descriptions on the different classification of HL7 Templates.

Document Templates

• A template applied to the CDA schema to produce a desired level of information structure and content for a particular purpose – a particular type of document.
• Analogous to a paper form with mandatory and optional sections and described level of detail for each section.
• If sections can be coded, the specific coding scheme and any additional constraints are usually specified.
• May reference other templates applied to specific sections or entries.

Atomic Concept Definition Templates

• A template applied to part of a static model that specifies the structure and permitted coding to completely define a particular clinical concept.
  • Any constraints on coded elements or value ranges are specified.
  • Optional relevant components that may add nuances in particular circumstances are included.
• Atomic Concept Definition Templates are designed to be reusable in many different contexts.
  • CEN defines Archetypes as atomic concept definitions formally approved by recognized clinical bodies.
• The stereotypical example is Blood Pressure, composed of 2 numerical measures with optional additional information about patient positioning, cuff size, etc.

Aggregate Measures Templates

• A template applied to an observation with multiple components that constrains the content and relationship of components.
• Constraints may be to optionality or to valid value ranges or coded value sets.
• Application of constraints may be conditional depending on values in other components.
• HL7 balloted static models have the information structures that can describe these component relationships, but to define a specific named set that can be referenced consistently would be a template.

Computed Measures Templates

• A template applied to an observation that has multiple components.
• The constraints apply to the content and relationships of the components, but also describes the computational algorithm that derives a computed measure from the component measures.
• An APGAR score is an example.

Assembly or sub-assembly Templates

• HL7 Templates applied to an “organizer” level of a static model that defines the content of components for a particular purpose.
• Constraints can be any structural or non structural variety and may reference other templates.
• In effect, the “Assembly” constraints are the sum total of all the constraints expressed in referenced templates plus any associated with the “Assembly” as a whole.