12.3 Pattern Definition - Content

12.3.1 Scope and Usage

This is NOT a resource. It is not part of the FHIR schema and cannot appear directly in FHIR instances. It is a logical model that defines a pattern adhered to by other resources. This pattern serves two purposes:

• It offers guidance to work groups designing resources and helps ensure consistency of content created by different work groups
• It provides a standard "view" that might be useful for implementers in processing and manipulating all resources that adhere to the same pattern. (Tooling that supports this may become available in a future release.)

This pattern describes common properties typically found on "definition" resources. "Definition" resources are resources that describe clinical, administrative or other events that can potentially occur. They do so in a manner that is independent of a particular patient or subject and independent of any particular timeframe. Examples include protocols, order sets, questionnaires, etc. Definitions are intended to be instantiated by Requests (orders, plans and proposals) and Events. For example a PlanDefinition might represent an order set that is subsequently instantiated by a combination of MedicationRequests and ServiceRequests and results in the execution of various MedicationAdministration, Procedure and Observation events. This pattern only applies to definitions of activities, not of objects or roles.

12.3.2 Boundaries and Relationships

This logical model is one of three common workflow patterns. The other two patterns are Event and Request. This pattern is followed by (or is intended to be followed) by a number of other FHIR resources/

Both definitions and requests deal with activities that "can" occur, but requests represent a specific intention for something to occur and are bound to a specific context of subject and time, while definitions represent mere "possibility" rather than intention and are independent of a specific subject or timeframe.

12.3.3 Background and Context

This model represents a pattern. It provides a standard list of data elements with cardinalities, data types, definitions, rationale and usage notes that will ideally be adhered to by resources that fall into the "definition" workflow category. However, adherence to this pattern is not mandatory. Not all healthcare domains are the same. Concepts that may be generally applicable (and thus are included in this standard pattern) might still not be relevant everywhere or may be sufficiently uncommon that they are more appropriate to include as extensions than as core properties of the resource. Work groups are encouraged to adjust descriptions, usage notes and rationale to be specific to their resource (e.g. use the term "protocol" or "questionnaire" rather than "definition"). As well, design notes in the comments column marked with [square brackets] identifies areas where domain variation is expected and encouraged. Other variation, including differences in names, cardinalities, data types and the decision to omit an element outright are also possible, but should be discussed with the FHIR Infrastructure work group's Workflow project to ensure the rationale for non-alignment is understood, to confirm that the deviation is necessary and to identify whether any adjustments to the pattern are appropriate.

Note that not all resources that contain Definition in their name are considered to be definition resources from a workflow perspective. For example, ActorDefinition, SpecimenDefinition, etc. are defining entities, not activities.

This pattern provides a linkage to the W5 list of standard data elements. Resources that adhere to this pattern should ensure their w5 mappings are consistent, as is their data element ordering.