By: Amos (Kippi) Bordowitz

Health Level 7® has announced the release of a new version of the HL7® FHIR® standard – version R4B. Let us review the changes and see how these can be poot to use in our daily work with FHIR®. All quotes
in this post are taken from the HL7® FHIR® specification website.

Please note that all new resources have very low maturity levels and are marked as either “Draft” or Trial use. As this is the case, tread with caution when making use of these resources as they might end up either being dropped altogether, or containing breaking changes in future versions.

FHIR® v.4.3 (R4B) - All the changes

General Changes

CodeableReference

A common pattern in healthcare records is that a single element may refer to either a concept in principle, or a specific instance of the concept as seen in practice. Imagine a patient is suffering some form of pain, say chest pain. One might want to refer to the pain as coded in, say, SNOMED CT. But another option would be to refer to the list of observations in the patient’s history where we might find a possible reason for this patient’s chest pain.

The CodeableReference datatype allows us to enter either a concept or Reference, or, if required, both, while still allowing binding to a ValueSet on the ‘concept’ element.

RatioRange

In certain
cases, there is a need to represent a range of ratios. For such cases, the RatioRange datatype was created. The RatioRange datatype should only be used to express a range of ratios if the relationship cannot be suitably expressed using a Range and a common unit.

To use it, you will need to enter two numerators (i.e., the number above the line in a common fraction): lowNumber and highNumber, as well as a denominator (the number under the line). The lowNumber
SHALL be lower than the highNumber.

Read the important caveats here.

New Resources

SubscriptionStatus

Maturity level: 0 / Draft

“The SubscriptionStatus resource describes the state of a Subscription during notifications.”

It contains a Reference to a Subscription, as well as it’s state and information regarding the
notification. Learn more here.

SubscriptionTopic

Maturity level: 0 / Draft

“Describes a stream of resource state changes or events and annotated with labels useful to filter projections from this topic… is used to define conceptual or computable events for Subscription resources. Conceptually, subscription topics specify:”

• What causes a notification
• What filters a client is allowed to request
• What related resources the server MAY include in notifications

Learn more here.

ManufacturedItemDefinition

Maturity level: 1 / Trial Use

“The definition and characteristics of a medicinal manufactured item, such as a tablet or capsule,
as contained in a packaged medicinal product.”

This resource is used to describe a physical medication item, in the state in which it is in after it
was manufactured, and before any changes were made to it. “The resource aims to capture the definition of a single medication item type, such as a tablet of aspirin with a certain form, shape, manufacturer. It is not intended to describe and be instantiated for each medication item, i.e. it is not an actual real instance of a tablet, but rather represents (e.g.) all tablets of the same medication item type, that are described by the ManufacturedItemDefinition”. Can describe tablets, liquids, powders etc., as well as their properties. E.g., “red
tablet with x mark”.

Learn more here.

AdministrableProductDefinition

Maturity level: 1 / Trial Use

“A medicinal product in the final form which is suitable for administering to a patient (after any
mixing of multiple components, dissolution etc. has been performed).”

This resource, which is populated by references to resources of type ManufacturedItemDefinition, “represents the final form of the product; hence it details properties such as the route, that only apply to the final product. It is a definitional resource, representing the properties of a product, but not the actual instance given to someone. When necessary to record that, a Medication resource is used.”

Learn more here.

ClinicalUseDefinition

Maturity level: 1 / Trial Use

“A single issue - either an indication, contraindication, interaction or an undesirable effect for a medicinal product, medication, device or procedure.”

Used to record a single instance of facts regarding a particular medication, device or procedure, in relation to its intended use, with information on side effects, interactions, risks/hazards etc.

Learn more here.

PackagedProductDefinition

Maturity level: 1 / Trial Use

“A medically related item or items, in a container or package.”

A medically related item, including its packaging, representing a unit ready for sale, supply etc. This resource contains recursive relationships so one must make sure they understand it fully before use.

Learn more here.

RegulatedAuthorization

Maturity level: 1 / Trial Use

“Regulatory approval, clearance or licencing related to a regulated product, treatment, facility or activity that is cited in a guidance, regulation, rule or legislative act. An example is Market Authorization relating to a  edicinal Product.”

“RegulatedAuthorization is a resource covering the authorization of a type of regulated product, treatment, facility or activity.” This resource deals with absolutely anything that requires regulation in the world of healthcare:

• products (drugs, devices etc.)
• treatments
• facilities
• clinical trials and related activities

Learn more here.

Citation

Maturity level: 0 / Trial Use

Note: the FHIR® management group presently considering whether this resource is appropriate to include in
the FHIR specification. As such we do not recommend using this resource.

“The Citation Resource enables reference to any knowledge artifact for purposes of identification and attribution. The Citation Resource supports existing reference structures and developing publication practices such as versioning, expressing complex contributorship roles, and referencing computable resources.”

Learn more here.

EvidenceReport

Maturity level: 0 / Trial Use

“The EvidenceReport Resource is a specialized container for a collection of resources and codable concepts, adapted to support compositions of Evidence, EvidenceVariable, and Citation resources and related concepts.”

Learn more here.

NutritionProduct

Maturity level: 0 / Trial Use

“A food or fluid product that is consumed by patients.”

Learn more here.

Resources removed from the specification

Medication Definition Module:

MedicinalProductAuthorization, MedicinalProductContraindication, MedicinalProductIndication, MedicinalProductInteraction, MedicinalproductManufactured, MedicinalproductPackaged, MedicinalproductPharmaceutical, MedicinalproductUndesirableEffect, SubstanceAmount, SubstanceNucleicAcid, SubstancePolymer, SubstanceProtein, SubstanceReferenceInformation and SubstanceSourceMaterial

Clinical Reasoning Module:

EffectEvidenceSynthesis and RiskEvidenceSynthesis

Reworked and/or renamed Resources

Note –  It is imperative to learn what has changed in each resource before making use of it.

Rework and rename:

• MedicinalProduct -> MedicinalProductDefinition
• MedicinalProductIngredient -> Ingredient
•  SubstanceSpecification -> SubstanceDefinition

Rework without rename:

• MarketingStatus (relax cardinality constraints) and ProductShelfLife Types
• Evidence and EvidenceVariable Resources
• Add canonical as an allowed type for subject[x] to ActivityDefinition and PlanDefinition

In conclusion:

FHIR® specification R4B, a steppingstone towards version 5, has made extensive changes, especially in the Medication Definition module. Make sure to learn these changes before making use of any resource and pay attention to the maturity levels.

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