This page is part of the FHIR Specification (v4.3.0: R4B - STU). The current version which supercedes this version is 5.0.0. For a full list of available versions, see the Directory of published versions

1.11 R4B Explanation

FHIR Management Group Work Group

Maturity Level: N/A

Standards Status: Informative

As the FHIR specification has matured, the cadence of release has gradually slowed (see the release history ), and the Covid pendemic exacerbated this trend. However there are parts of the FHIR specification that are still very new, which need a higher release frequency in order to continue developing.

The R4B release incorporates changes to a few selected modules, while preserving compatibility across the rest of the specification. Implementers that do not use the specific portions where changes have been made can continue to use either R4 or R4B without any functional difference - there are no impactful changes other than those listed on this page. This is the vast majority of existing implementers.

HL7 is maintaining a set of information about implementation strategies with tooling support for dealing with R4 and R4B .

1.11.1 Changes between R4 and R4B

The changes are limited to particular areas of the specification. See the version history for further details. The following general changes were made:

• Add CodeableReference and RatioRange types
• Add NutritionProduct Resource
• Refine some invariants that behaved erroneously with missing data (no new restrictions were introduced)

1.11.1.1 Medication Definition Module

This module has had extensive changes in R4B:

• Add new Resources AdministrableProductDefinition, ClinicalUseDefinition, PackagedProductDefinition, ManufacturedItemDefinition and RegulatedAuthorization
• Rework MarketingStatus (relax cardinality constraints) and ProductShelfLife Types
• Rework & rename MedicinalProduct -> MedicinalProductDefinition
• Rework & rename MedicinalProductIngredient -> Ingredient
• Rework & rename SubstanceSpecification -> SubstanceDefinition
• Remove MedicinalProductAuthorization, MedicinalProductContraindication, MedicinalProductIndication, MedicinalProductInteraction, MedicinalproductManufactured, MedicinalproductPackaged, MedicinalproductPharmaceutical, MedicinalproductUndesirableEffect, SubstanceAmount, SubstanceNucleicAcid, SubstancePolymer, SubstanceProtein, SubstanceReferenceInformation and SubstanceSourceMaterial resources

1.11.1.2 Clinical Reasoning

This module has had changes around the Evidence Based Medication resources:

• Rework Evidence and EvidenceVariable Resources
• Add Citation and EvidenceReport Resources
• Remove EffectEvidenceSynthesis and RiskEvidenceSynthesis Resources
• Add canonical as an allowed type for subject[x] to ActivityDefinition and PlanDefinition

1.11.1.3 Exchange

R4B introduces a new subscription interaction model that defines additional subscription related resources:

• Add SubscriptionStatus and SubscriptionTopic Resources