Use the FHIR $apply operation on a PlanDefinition to generate a CarePlan and RequestGroup for a patient enrolled in a chronic disease management protocol

In-depth guide

Steps

1. POST a Parameters resource to the PlanDefinition's $apply endpoint carrying the required subject parameter referencing the Patient, the encounter parameter if applying within an active encounter context, and the practitioner parameter identifying the applying clinician
2. Confirm that the PlanDefinition has action elements with condition elements specifying applicability conditions in CQL or FHIRPath; the $apply operation evaluates these conditions against the patient context to determine which actions generate Request resources and which are skipped
3. Parse the returned CarePlan resource to identify which actions were instantiated into activity elements; each activity will reference a RequestOrchestration (formerly RequestGroup in R4) containing the generated ServiceRequest, MedicationRequest, or Task resources
4. For actions that require a questionnaire to be completed before the activity is applicable, follow the relationship between the CarePlan activity and the linked Questionnaire and use $populate to pre-fill the Questionnaire from existing patient data before presenting it for completion
5. POST the returned CarePlan to the FHIR server to persist it; then POST any generated Request resources that were returned as contained resources or as separate resource references in the CarePlan activity elements
6. If the PlanDefinition version changes after initial application, call $apply again with the same patient context and compare the resulting RequestOrchestration to the existing one to identify new actions that must be added to the patient's active care plan