FHIR Implementation Guide Medication Process Medication Process 9 version 2.0.0 bèta

1 Introduction

This is the implementation guide (IG) for the information standard Medication Process 9 (MP9) version 2.0.0 using the HL7® FHIR® standard. The MP9 standard is described in this functional specification and implemented here using FHIR version R4. This implementation guide assumes that the reader is familiar with both the functional specification and this version of FHIR.

Apart from this document, the guidelines as specified in the general FHIR Implementation Guide apply. In particular, the reader should take note of the Use case overarching principles and the use of FHIR packages. Where the general IG uses the term 'use case', this IG follows the functional specification in using th term 'transaction' for the various processes that are described. The functional specification uses the term 'use case' for more practical examples.

This IG first describes the boundaries and relationships in place, after which the implementation is describer per transaction.

2 Boundaries and relationships

2.2 Mappings between profiles and data set

Each transaction starts with links to the functional definition in an ART-DECOR publication and references one or several FHIR profiles. Where the functional definition contains all specific data elements for the transaction (prefixed with ‘dataelement-mp920’), the FHIR profiles only contain a mapping to these data elements that do not have a dependency on a zib counterpart. For example: ‘mp-dataelement920-83’ (MedicationAgreementDateTime) has a relation with the zib element with id ‘NL-CM-9.6.19757’, therefore no mapping with ‘mp-dataelement920-83’ can be found in the profiles. On the other hand, ‘mp-dataelement920-42’ (Identification) has no relation with a zib element, therefore a mapping can be found in the relevant FHIR profile.

Because of open world modelling, the cardinality of elements in the FHIR profiles can be less strict than the cardinalities in the ART-DECOR transactions. However, the latter cardinality is leading when it comes to exchanging building blocks in the context of a specific transaction. For example: in the nl-core-MedicationAgreement profile, .requester has a cardinality of 0..1, while in the Serve Medication data ART-DECOR transaction, the Prescriber element has a cardinality of 1..1 R. Therefore, .requester is expected to be filled with either a Reference to an nl-core-HealthProfessional-PractitionerRole resource or a [DataAbsentReason extension, see the general FHIR IG on 'Missing information'. Profiles do not explicitly define if or how to apply FHIR DataAbsentReason.

Each transaction contains a Patient building block with cardinality 1..1 M. This patient is the subject of all other building blocks in the transaction, although no explicit relation exists in the dataset. Therefore, a reference to a Patient resource conforming to the nl-core-Patient profile is expected in .subject of each FHIR instance of each building block.

Relations between different building blocks exist in transactions by means of concepts with a name starting with ‘Relation…’ (Dutch: ‘Relatie…’) of data type Identification, for example RelationAdministrationAgreement (mp-dataelement920-1328) in building block MedicationAgreement. These relations are mapped to the FHIR data type ‘Reference’. Implementers SHOULD use literal references (using .reference) instead of logical references (using .identifier) where possible, see the general FHIR IG on the Reference data type.

2.3 Pharmaceutical treatment

The MP9 transaction data sets reference a container ‘Pharmaceutical treatment’ (Dutch: ‘Medicamenteuze behandeling’), which contains all medication building blocks relevant to the transaction. For the specification of the Pharmaceutical treatment, see the functional specification. In FHIR, the Pharmaceutical treatment does not have an explicit resource representation. Instead, each medication building block contains the PharmaceuticalTreatmentIdentifier extension which contains the ‘Pharmaceutical Treatment Identifier’. This Identifier shall be the same across different related medication resources that constitute one pharmaceutical treatment. The custom search parameter pharmaceutical-treatment-identifier, see 'Search parameters' is used within the 'Medication data' transaction to query a server for all building blocks within a specific Pharmaceutical treatment.

2.4 Patient identification

This implementation guide assumes that the client system is able to make a connection to the right server that contains the patient's information. It does not provide information on finding the right server nor does it provide information about security. Moreover, each transaction is performed in the context of a specific (authenticated) patient, whose context might have been established using the authentication mechanisms described in external specifications such as the MedMij 'Afsprakenstelsel' or through the usage of search parameters for patient identification. Each server is required to perform filtering based on the patient associated with the context for the request or based on the patient identification search parameters, which is a chained search parameter for all resource types except Patient, so only the records associated with the authenticated patient are returned.

When patient identification requires the use of search parameters, the following search parameters SHALL be supported:

• Patient: identifier
• MedicationRequest: patient
• MedicationDispense: patient
• MedicationStatement: patient
• MedicationAdministration: patient

An example of a request that retrieves all MedicationRequest resources of a patient with a fake BSN of 11122233:

GET [base]/MedicationRequest?patient.identifier=http://fhir.nl/fhir/NamingSystem/bsn|111222333

All request examples in this document do not include patient identification mechanisms. Requesters are assumed to include these if necessary.

2.5 Resource identification

All profiles used within the MP9 information standard contain .identifier elements with a cardinality of 0..* because of open world modelling. However, all ART-DECOR transactions referenced within this IG assign a 1..1 Required cardinality, meaning a stable identifier SHOULD be provided, or the DataAbsentReason extension if a value is missing. Identifiers SHALL contain both a .system and a .value.

Because in HL7v3 (CDA) an identifier can only be composed using OIDs, the .system SHALL be an OID to accommodate compatibility in transformations to and from FHIR. The Netherlands HL7v3 datatype II also defines additional restrictions on the maximum length of both @root and @extension (equivalent to respectively .system and .value in FHIR). For the same compatibility reasons, .system SHALL have a maximum of 128 characters and .value SHALL have a maximum of 64 characters.

3 Transactions

This section describes the FHIR implementation of all transactions listed in [mp:V2.0.0_Ontwerp_medicatieproces_9_ENG#Information_systems_and_transactions|section 7 of the functional specification]. Transactions are paired per transaction group. Where the functional specification uses the terms ‘Consulting’ and ‘Making available’, this IG uses the terms ‘Retrieving’ and ‘Serving’.

3.1 Medication data (Retrieve/Serve)

The retrieve medication data transaction is used by the client to retrieve medication data from a server. The client can retrieve its desired information by searching for specific medication building blocks.

Transaction group	Transaction	Actor	System role	FHIR CapabilityStatement
Medication Data (PULL)	Retrieving medication data	Client	MP-MGR	CapabilityStatement: Client
	Serving medication data	Server	MP-MGB	CapabilityStatement: Server

The names of the transaction groups and transactions link to the functional definition in an ART-DECOR publication which details per scenario which data elements are expected to be supported.

3.1.1 Retrieve (request messages)

When a patient or healthcare professional wants to obtain all medication data or specific parts matching various parameters, it issues a retrieve medication data request message. This message uses the HTTP GET method parameterized query against the server's medication FHIR endpoints. These endpoints can be one of the following:

• MedicationRequest
• MedicationDispense
• MedicationStatement
• MedicationAdministration

The search interaction is performed by an HTTP GET conform the FHIR search specification, as shown below. This URL is configurable by the client by configuring the query search. Multiple request messages may be needed to retrieve all desired information.

GET [base]/[type]{?[parameters]}

3.1.1.2 Search Parameters

The client MAY supply, and the server SHALL be capable of processing, all search parameters listed in the table below.

MP9 search parameters	Description	FHIR search parameter	FHIR resource	Example
Identification	Search on identifier.	identifier	MedicationRequest, MedicationDispense, MedicationStatement, MedicationAdministration	Retrieves a MedicationRequest resource with a specific identifier. GET [base]/MedicationRequest?identifier=http://example.nl/fhir/NamingSystem/MedicationRequest|999922448
Identification	Search on the pharmaceutical treatment identifier. Note: retrieval of all medication resoures belonging to one pharmaceutical treatment requires to search on all medication resource types.	pharmaceutical-treatment-identifier	MedicationRequest, MedicationDispense, MedicationStatement, MedicationAdministration	Retrieves all MedicationRequest resources that are part of a pharmaceutical treatment with a specific identifier. GET [base]/MedicationRequest?pharmaceutical-treatment-identifier=http://example.nl/fhir/NamingSystem/pharmaceuticaltreatment|1247848
Type	Search on type of medication building block.	category	MedicationRequest	Retrieves all MedicationRequest resources that represent the building block MedicationAgreement. GET [base]/MedicationRequest?category=http://snomed.info/sct|16076005 Retrieves all MedicationRequest resources that represent the building block DispenseRequest. GET [base]/MedicationRequest?category=http://snomed.info/sct|52711000146108 Retrieves all MedicationRequest resources that represent the building block VariableDosingRegimen. GET [base]/MedicationRequest?category=http://snomed.info/sct|395067002
			MedicationDispense	Retrieves all MedicationDispense resources that represent the building block MedicationDispense. GET [base]/MedicationDispense?category=http://snomed.info/sct|373784005 Retrieves all MedicationRequest resources that represent the building block AdministrationAgreement. GET [base]/MedicationRequest?category=http://snomed.info/sct|422037009
			MedicationStatement	Retrieves all MedicationStatement resources that represent the building block MedicationUse2. GET [base]/MedicationStatement?category=http://snomed.info/sct|422979000
			MedicationAdministration	Retrieves all MedicationAdministration resources that represent the building block MedicationAdministration2. GET [base]/MedicationAdministration?category=http://snomed.info/sct|18629005
MedicationCode	Search on medication code.	medication.code	MedicationRequest, MedicationDispense, MedicationStatement, MedicationAdministration	Retrieves all MedicationRequest resources that represent the building block MedicationAgreement and have Carbasalaatcalcium Sandoz 600 30 as medication. GET [base]/MedicationRequest?category=http://snomed.info/sct|16076005&medication.code=urn:oid:2.16.840.1.113883.2.4.4.8|13610554
PeriodOfUse	Search on medication use in the past, present or future within the specified time period.	period-of-use	MedicationDispense, MedicationRequest	Retrieves all MedicationRequest resources that represent the building block MedicationAgreement and were in effect from 01-01-2010. GET [base]/MedicationRequest?category=http://snomed.info/sct|16076005&period-of-use=ge2010-01-01
DispensePeriod	Returns all medication dispenses within the specified time period.	whenhandedover	MedicationDispense	Retrieves all MedicationDispense resources that represent the building block MedicationDispense and were handed over within a 2 year period. GET [base]/MedicationDispense?category=http://snomed.info/sct|373784005&whenhandedover=ge2010-01-01&whenhandedover=le2011-12-31
AdministrationPeriod	Returns all medication administrations within the specified time period.	effective-time	MedicationAdministration	Retrieves all MedicationAdministration resources that represent the building block MedicationAdministration2 and were administration happened within a 2 year period. GET [base]/MedicationAdministration?category=http://snomed.info/sct|18629005&effective-time=ge2010-01-01&effective-time=le2011-12-31
-	The client may request that the server returns resources related to the search results, in order to reduce the overall network delay of repeated retrievals of related resources. Supporting the include of the Patient and Medication resources referenced by building blocks is required. Others (Organization, Location, PractitionerRole, Practitioner, RelatedPerson, Observation) are optional. However: all resources referenced per literal reference SHALL be resolvable per the Nictiz IG.	_include=[type]:patient _include=[type]:medication	MedicationRequest, MedicationDispense, MedicationStatement, MedicationAdministration	Retrieves all MedicationRequest resources that have Carbasalaatcalcium Sandoz 600 30 as medication and includes the Medication resource in the search results. GET [base]/MedicationRequest?medication.code=urn:oid:2.16.840.1.113883.2.4.4.8|13610554&_include=MedicationRequest:medication

The following custom search parameters are defined for this transaction:

• http://nictiz.nl/fhir/SearchParameter/pharmaceutical-treatment-identifier
• http://nictiz.nl/fhir/SearchParameter/category
• http://nictiz.nl/fhir/SearchParameter/period-of-use

3.1.1.3 Retrieve all medication data

To retrieve all known medication data, a client has to execute the following requests to retrieve all known medication data per building block, including referenced Medication resources:

GET [base]/MedicationRequest?category=http://snomed.info/sct|16076005&_include=MedicationRequest:medication
GET [base]/MedicationRequest?category=http://snomed.info/sct|52711000146108&_include=MedicationRequest:medication
GET [base]/MedicationRequest?category=http://snomed.info/sct|395067002&_include=MedicationRequest:medication
GET [base]/MedicationDispense?category=http://snomed.info/sct|373784005&_include=MedicationDispense:medication
GET [base]/MedicationDispense?category=http://snomed.info/sct|422037009&_include=MedicationDispense:medication
GET [base]/MedicationStatement?category=http://snomed.info/sct|422979000&_include=MedicationStatement:medication
GET [base]/MedicationAdministration?category=http://snomed.info/sct|18629005&_include=MedicationStatement:medication

3.1.2 Serve (response messages

The server returns an HTTP Status code appropriate to the processing outcome and returns a Bundle, with Bundle.type=searchset, including the resources matching the search query medication data. The resources included in the Bundle SHALL conform to the profiles listed in section 2.1.

3.3 Medication overview (Retrieve/Serve)

The retrieve medication overview transaction is used by the client to retrieve a medication overview from the server.

3.3.1 Actors

Transaction group	Transaction	Actor	Role
Retrieve Medication overview (PULL)	Consulting medication overview	Client	Request Medication overview
	Making medication overview available	Server	Serve Medication overview

The names of the transaction groups and transactions link to the functional definition in an ART-DECOR publication which details per scenario which data elements are used.

3.3.2 Invocations

3.3.2.1 Request message

When the patient or healthcare professional wants to obtain a patient's medication overview, it issues a Consulting medication overview request message. This message uses an extended operation on the RESTful API to obtain a medication overview from a server. An operation is needed because the server will formulate the content of the response based on its internal business logic. The medication overview can not easily be described by standardized restful requests.

The client executes a medication-overview operation with HTTP POST against the server base endpoint as shown below.

POST [base]/$medication-overview

3.3.2.2 Response message

The server returns a HTTP Status code appropriate to the processing of the operation. The successful outcome of the $medication-overview operation is the body of the medication overview response message. Successful processing of this operation should result in a Bundle recourse of type 'searchset', containing one List and one Patient resource as entries along with all the resources that represent the current medication overview. These resources SHALL be referenced from the List resource. The clinical content of the medication overview is defined in the Medication Process specification.

The Bundle profile represents the structure of the retrieve medication overview response message. The List profile represents the medication overview. The List contains the medication overview metadata and references to all resources that constitute the medication overview. These resources are included in the Bundle as entries. The Bundle.total value contains the number of matching zib: MedicationUse, AdministrationAgreement and MedicationAgreement. Other included resources, such as Medication resources, are not included in the total. The returned Bundle has at least one List and one Patient resource. The returned data to the client SHALL be a valid instance of its applicable profile as shown in the List of Profiles.

Note that the medication resources blocks are grouped per 'pharmaceutical treatment' conform to the Medication Process specification. Grouping SHALL be done by use of a 'Pharmaceutical Treatment Identifier'. This identifier shall be the same across different related medication resources that constitute one medication treatment. The PharmaceuticalTreatmentIdentifier extension is to be used for this grouping purpose.

4 Release notes

Release notes can be found on the functional design page.