Referential integrity
Dangling `Practitioner` / `Organization` references in `PractitionerRole`, unresolvable `managingOrganization` in Location, and Organization-to-HealthcareService coverage.
Headline
Referential integrity is clean but coverage is sparse. 0.000% of 17.0M declared cross-resource references actually dangle (target missing). But only 3.0% of Endpoints carry a managingOrganization (149,080 of 5,043,524) and only 76.0% of Locations do (2,654,922 of 3,494,239). H8: the NPD bulk export does not ship HealthcareService (NDH IG defines 10 resources; NPD ships 6).
0 / 17.0M = 0.00%
unit: percent
What this means
Payer data teams
97% of NDH Endpoints have no managingOrganization back-reference. You can’t reliably traverse Endpoint → Organization. Work around via NPI-based secondary joins (NPPES, CAQH).
Provider data teams
If your organization has Endpoints registered, audit whether they declare managingOrganization pointing back to you. The 97% coverage gap is in this exact pointer.
FHIR implementers
Integrity of DECLARED references is 100% — zero dangling refs across 17M edges. The defect pattern is under-population, not broken pointers. Trust your resolver, but expect 4 of the 10 NDH IG resources (HealthcareService, InsurancePlan, Network, Verification) to be absent entirely.
Regulators
The NDH bulk export omits 4 of the 10 NDH-IG resources (HealthcareService + InsurancePlan + Network + Verification). Any rule citing those resources cannot be measured from the current public-use artifact.
Null hypothesis
Cross-resource references resolve at ≥99% inside the bulk export.
Denominator
All reference fields across `PractitionerRole.practitioner`, `PractitionerRole.organization`, `Location.managingOrganization`, and `HealthcareService.providedBy`.
Data source
Edge tuples extracted from the NPD bulk export in a single streaming pass, queried in DuckDB.
Notes
Integrity (dangling rate among declared references): H6a PR→Practitioner 0.0000%, H6b PR→Organization 0.0000%, H7 Location→Org 0.0000%, Endpoint→Org 0.0000%. All near zero — when a reference is declared, it resolves. Coverage (share of rows with the optional reference populated): PR→Practitioner 100.00% (required), PR→Organization 97.98%, Location→managingOrganization 75.98%, Endpoint→managingOrganization 2.96%. The Endpoint→Organization gap pairs with H5 (98.69% of Orgs have no Endpoint referencing them) — the Endpoint↔Organization link is sparse in both directions. H8 requires HealthcareService, which is one of four NDH IG resources (HealthcareService, InsurancePlan, Network, Verification) absent from the 2026-04-09 NPD bulk export. Any HealthcareService-based check cannot be performed from NPD alone.