MedMij, BgZ, zibs and the VWS FHIR-besluit: four Dutch layers that are not one API
MedMij is patient/PHR exchange. BgZ is the Dutch patient-summary dataset. zibs are clinical models. The VWS FHIR-besluit pairs STU3+zib2017 and R4+zib2020 — MedMij is not R4-only.
Ala Ben Aicha
Direct answer
MedMij is patient/PHR exchange. BgZ is the Dutch patient-summary dataset. zibs are clinical models. The VWS FHIR-besluit pairs STU3 with zib2017 and R4 with zib2020; MedMij is not R4-only.
Four names, four jobs
Dutch FHIR conversations collapse MedMij, BgZ, zibs and the ministry FHIR decision into “the Dutch profile”. They are stacked layers. A MedMij PGO (personal health environment) that speaks BgZ is not a generic R4 Patient server, and an R4 nl-core beta is not a MedMij production package.
| Layer | Owner / home | Canonical / package | What it is | What it is not |
|---|---|---|---|---|
| zibs (Zorginformatiebouwstenen) | Nictiz zib-centrum; zibs.nl | Clinical information models, versioned (2017, 2020, …) | Semantic building blocks: what a blood pressure or patient name means, independent of FHIR | Not a FHIR IG, not a REST API |
| BgZ (Basisgegevensset Zorg) | Nictiz; informatiestandaarden.nictiz.nl; package family nictiz.fhir.nl.stu3.bgz |
Patient-summary dataset composed of zibs; FHIR STU3 profiles in Nictiz-STU3-BgZ |
The Dutch patient-summary content that MedMij and other programmes reuse | Not MedMij itself, not IPS, not EEHRxF Patient Summary |
| MedMij | MedMij / Nictiz; MedMij FHIR IG | STU3 packages still in production (nictiz.fhir.nl.stu3.zib2017 2.3.x, medmij.fhir.nl.stu3.core); R4 medmij.fhir.nl.r4.core 1.1.0 exists alongside |
Patient/PHR exchange afsprakenstelsel: how a PGO talks to a zorgaanbieder | Not a hospital EHR interface, not already R4-only |
| VWS FHIR-besluit (21 Oct 2022) | Ministry of Health, Welfare and Sport | Policy pairing, not a package | STU3 + zib2017 or R4 + zib2020; not other FHIR versions, not mixed pairs | Not a cutover date. It does not retire MedMij STU3 |
Primary sources: Nictiz information standards, the VWS FHIR-besluit (21 October 2022). R4 nictiz.fhir.nl.r4.nl-core is published in beta (0.12.0-beta sequence on Simplifier). Do not treat a beta nl-core package as the MedMij production contract.
The identifier: BSN
Country-specific identifier for Dutch Patient resources is the Burgerservicenummer (BSN). HL7 Netherlands / Nictiz Patient profiles fix:
http://fhir.nl/fhir/NamingSystem/bsn
OID 2.16.840.1.113883.2.4.6.3. Nine digits, eleven-proof. Use of BSN in care is constrained by Wbsn-z; research and apps without a processing agreement are typical reasons not to send it. Do not publish a real BSN. Keep the system URL and a dummy value in fixtures.
A hospital MRN is an additional identifier. It does not replace BSN when the receiver is a MedMij or national Dutch FHIR endpoint.
What to implement first
- If the buyer is a PGO or MedMij zorgaanbieder: the MedMij information standard named in the contract, usually STU3 + zib2017 BgZ. Confirm the package (
nictiz.fhir.nl.stu3.zib2017/nictiz.fhir.nl.stu3.bgz) rather than assuming R4. - If the buyer is on an R4 / zib2020 path:
nictiz.fhir.nl.r4.nl-core(implementable layer) plusnictiz.fhir.nl.r4.zib2020(abstract zib layer). The zib2020 profiles are marked abstract; do not implement the abstract package as the wire format. - If the buyer says “Dutch FHIR” without naming MedMij, BgZ or a Nictiz information standard: stop and name the standard. Wegiz (mandatory exchange) names use cases; it does not by itself pick STU3 or R4.
- For EHDS category 1, BgZ is a cousin of IPS / EU Patient Summary, not a drop-in. See EU Core and EHDS.
The country hub is the map. The HL7 FHIR R4 guide is the generic REST primer — MedMij search and zib bindings override it.
What this is not
This article is not MedMij qualification, not a Nictiz certificate, not a Wegiz legal opinion, and not permission to process BSN. Shipping STU3 BgZ profiles in a lab does not enrol you in the MedMij afsprakenstelsel. I do not perform MedMij deelnemer tests. Nothing here is clinical advice.
Related reading
For mapping work against MedMij or nl-core, use HL7 FHIR integration or start a project.