The InteropEHRate information model that allows for the exchange of data in the context of a research project takes into account the main aspects of the research protocol within different information categories.

Table 4.1: Categories of information represented by the RDD domain model

Information category	Requirement
unstructured / human readable definition of the research project	Description of the research project containing human readable dataset definitions, enrollment and exit criteria, definitions of enrollment and data collection periods, in-phone anonymization requirements, as well as metadata describing the research, in a way understandable for citizens
structured / machine processable definition of the research project	Definition of the research project containing structured dataset definitions, enrollment and exit criteria, definitions of enrollment and data collection periods, in-phone anonymization requirements, as well as metadata describing the research
data security and access control	Approval / Consent of the citizen to participate in the study
data set results	Aggregated and pseudonymized or anonymized citizen’s medical data

The following domain model outlines these four aspects from a high-level perspective. The model uses elements from the [FHIR] standard, which enables direct interoperability with the FHIR-based S-EHR data structures.

Research Definition Document

The Research Definition Document describes the rules for participating in a research study. It consists of several domain classes which are described in the following sections.

Further information on the realization can be found at Instructions - Research Definition Document (RDD).

Research Study

This domain class represents essential information of a research study in which S-EHR users can participate. The aims of a research study are to improve or develop new methods of health care by using scientific methods. The following table describes the relevant attributes.

Table 4.2: Members of the ResearchStudy resource

Attribute	Description	Cardinality	Data type	Value Set
id	Logical identifier of the research study. Once assigned, it never changes.	1..1	string	-
identifier	Unique identifier of the research study. This is a business identifier, not a resource identifier.	1..*	Identifier	-
text	Human-readable summary of the resource.	1..1	Narrative-IEHR	-
title	Title of the research study.	1	String	-
status	Status of the research study.	1	Coded Value	ResearchStudyStatus
primaryPurposeType	Purpose of the research study.	1	Coded Value	ResearchStudyPrimaryPurposeType
phase	Phase of the study if part of another study.	0..1	Coded Value	ResearchStudyPhase
contact	Contact information to research study.	1..*	Reference (Complex Data Type representing contact details)	-
description	Human-readable description (including data retention period, purpose of research and description of usage restrictions of data within the research protocol, description of the research centre that will coordinate the specific study and of the specific research centre (Local Research Centre) that will receive and process the shared health data).	0..1	markdown	-
period	Planned duration of the research or study as a whole, incorporating both the enrollment phase and the data delivery phase, as well as possible study specific time periods.	1	Period	-
site (participating Research Centers)	List of Research Centres (and relative regions) that a patient participating in the study can select as a Reference Research Centre for the specific described study.	1..*	Reference(ResearchLocation)	-
enrollment (cohort)	A list of planned citizen cohorts, incorporating the enrollment criteria for the evaluation of candidates.	1..*	Reference(Cohort-IEHR)	-
extension:RequestedAnonymizationType	-	1	Coded Value	AnonymizationValueSet(anonymization, pseudonymization)
extension: DataSetDefinition	This is a link to the data selection	1..*	DataSetDefinition - IEHR referring to DataRequirement - IEHR	-
extension: EnrollmentPeriod	The period during which new patients can enroll in the study	1	Period	-
extension:Questionnaire	This is a link to questionnaires with additional informations	0..*	QuestionnaireExtension - IEHR including a mandatory deadline (type dateTime), reminder frequency (type Timing) and a Reference(Questionnaire - IEHR)	-

In addition to the general metadata, the domain class Research Study includes references to the domain classes Research Center, Cohort, Data Set Definition and Research Subject.

Cohort

The EnrollmentLogic association enables a structured or unstructured definition of the actual query. The enrollment logic describes different enrollment criteria, or exit criteria if negated, for a patient’s participation in a research study, including e.g. minimum or maximum values for patient demographic data, the presence or absence of a certain diagnosis within a certain time period, a patient’s drug therapy within a certain time frame, and many more.

Usage of structured data set description Citizen’s characteristics:

A structured description of the enrollment criteria based on a common vocabulary is supported. The following table lists the features of this structured characteristic description.

Table 4.4: Members of the Citizen’s Characteristics resource

Attribute	Description	Cardinality	Data type	Value Set
kind of characteristic	Selection of the desired type of characteristic defining an enrollment criterion, based on a common vocabulary / Value Set, e.g. diagnosis.	1	Coded Value	to be defined, shall contain items such as age, diagnosis, medication, gender, etc.
Value	Value of the characteristic according to and depending on the kind of characteristic, e.g. a specific code of a diagnosis or a description.	1	String	-
exclude	Specifies whether the characteristic is an inclusion or exclusion criterion.	1	Boolean	true,false
period	Specifies a date or period of the characteristic’s existence or application, e.g. when a diagnosis has been raised.	0..1	Date Time	-

Data Set Definition

Aligned with the enrollment criteria, the data set definition allows for a structured or unstructured definition of the actual query. The data set definition defines which data sets and data items of the citizen cohorts shall be requested and delivered to the researcher. The data set definition is therefore only applicable for the participating citizens of a cohort of the research study.

See Instructions - Customized Data Requests, too.

Usage of structured data set description Data characteristics:

A structured description of the requested data items based on a common vocabulary is supported. The following table lists the features of this structured characteristic description.

Table 4.6: Members of the DataSetDefinition resource

Attribute	Description	Cardinality	Data type	Value Set
url	Url that defines the DataSetDefinition	1	uri	fixed:"http://interopehrate.eu/fhir/StructureDefinition/DataSetDefinitionExtension-IEHR"
extension:DataRequirement	Extensions that contain the dataRequierements	1..*	Extension	-

Table 4.6.1: extension:DataRequirement

Attribute	Description	Cardinality	Data type	Value Set
url	Url that defines this extension	1	uri	fixed:"DataRequirement"
value	DataRequirement that characterise the data	1	DataRequirement - IEHR	-

Table 4.7: Members of the DataRequirement - IEHR resource

Attribute	Description	Cardinality	Data type	Value Set
extension:FunctionExtension-IEHR	Used to describe how requested data should be processed. See Instructions - Data Processing Instructions.	0..1	Complex	fixed url:"http://interopehrate.eu/fhir/StructureDefinition/FunctionExtension-IEHR"
extension:FrequencyExtension-IEHR	The Frequency in which the data should be provided. See Instructions - Data Transmission Frequency.	0..1	Timing	fixed url:"http://interopehrate.eu/fhir/StructureDefinition/FrequencyExtension-IEHR"
codeFilter.code	Code filters specify additional constraints on the data, specifying the Value Set of interest in a particular element of the data.	0..*	Coding - IEHR	ValueSet CodingOperator - IEHR used in Coding-IEHR.

Table 4.7.1: extension:FunctionExtension - IEHR

Attribute	Description	Cardinality	Data type	Value Set
extension:Name	Name of the function, bond to a corresponding value set containing the available function codes.	1	Extension	-
extension:Parameter	Parameter of the function. The use and allowed cardinality of the parameter extension changes depending on the name of the called function.	0..*	Extension	-

Table 4.7.2: extension:Name

Attribute	Description	Cardinality	Data type	Value Set
url	Url that defines this extension	1	uri	fixed url:"Name"
value[x]	The actual value in form of a code form the FunctionCodesValueSet-IEHR.	1	Coding	ValueSet FunctionCodes - IEHR

Table 4.7.3: extension:Parameter

Attribute	Description	Cardinality	Data type	Value Set
url	Url that defines this extension	1	uri	fixed url:"Parameter"
value[x]	The actual value of the parameter, depending on the name of the called function. E.g. The count function returns only the number of resources, that fulfill the requirement. This function does not need any parameters and constrain extIEHR-2 enforces this.	1	string	-

Reference Research Center

A research center is an organization participating in the research study. The relevant attributes of the domain class Reference Research Center are listed below.

Table 4.10: Members of the ReferenceResearchCenter-IEHR resource

Attribute	Description	Cardinality	Data type	Value Set
id	Unique identifier of the reference research center.	0..*	Identifier	-
name	Name of the reference research center.	1	String	-
speciality	Speciality of the reference research center.	1..*	Coded Value	-
address	Address information of the reference research center.	1	Complex Data Type representing address information	-
telecom	Contact information of the reference research center.	1	Reference (Complex Data Type representing contact details)	-
endpoint	Service Endpoint (research protocol) of the reference research center.	1	Reference(Endpoint)	-

Questionnaire-IEHR

The QuestionnaireExtension-IEHR (formerly RDDQuestionnaire) contains a questionnaire that the patient has to complete. It additionally defines the deadline for the questionnaire and how frequently the patient should be reminded to complete it. The relevant attributes of the domain class RDDQuestionnaire are listed below.

Table 4.11: Members of the QuestionnaireExtension-IEHR resource

Attribute	Description	Cardinality	Data type	Value Set
url	Url that defines this extension	1	uri	fixed:"http://interopehrate.eu/fhir/StructureDefinition/QuestionnaireExtension-IEHR"
extension: Questionnaire	Reference to the questionnaire	1	Reference (Questionnaire)	-
extension: Deadline	The deadline for the questionnaire.	1	DateTime	-
extension: ReminderFrequency	Defines how often the patient should be remided to complete the questionnaire.	1	Timing	-

Table 4.11: Members of the Questionnaire-IEHR resource

Attribute	Description	Cardinality	Data type	Value Set
id		1	string	-
extension: CodeSystemExtension-IEHR	Reference to the questionnaire	1	Reference (CodeSystemQuestionnaire-IEHR)	-
item	A question of the questionnaire, represented as a code from the referred CodeSystem.	0..*	-	-