eHealth Infrastructure (v2019.5.3)
Introduction to the eHealth domain can be found at the wiki site.
The eHealth Infrastructure is based on an open modeling approach to using FHIR. With the open modeling, optional elements of the various FHIR resources have been retained even when not included in the initial data requirements. This except the few odd occurrences where elements have been removed to reduce they ways in which resources can be connected as the fewer ways suffice.
Compared to the closed modeling approach, where those (initially) superfluous elements are removed, the open modeling approach is prepared for adaptation. It enables an evolutionary use of elements where parties can agree on supporting otherwise unused elements for, say, pilot projects and then propagate use of the elements once proven valuable. This without interfering with regular use of the resources.
Elements of type Coding and CodeableConcept are used throughout the resources and the profiles that make up the eHealth Infrastructure clinical interface. Most often the elements where these types are used have a binding to a ValueSet specifying the allowed set of concepts. When assigning a value to such an element, that value must also be found in the corresponding ValueSet.
Coding (which is used in CodeableConcept) contains elements code and system which are optional
as per the definition in FHIR.
In scope of the eHealth Infrastructure, however, code and system shall be provided
at all times when expressing value for Coding (and CodeableConcept) type of elements.
The services comprising the eHealth Infrastructure must be expected to introduce verification hereof
at any time.
eHealth Infrastructure security mechanisms are described on the wiki site.