What are the Types/Classifications of Templates?

HL7 Templates can be classifies differently according to the roles that they play i 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.