FHIR-to-CDISC mapping refers to the technical and subject-matter alignment of health data provided from care delivery systems via the HL7 FHIR standard with clinical research data structures. Vulcan Real World Data is an HL7 FHIR implementation guide and a research project that supports the standardised provision of data from electronic health records for clinical research and regulatory purposes. The term therefore describes an interoperability pathway, not the quality or evidentiary value of real-world data itself.
Two standards with different roles
FHIR organises the exchange of health information between IT systems. In an electronic health record, for example, diagnoses, laboratory values, medications or observations may be available as FHIR resources and retrieved via interfaces. CDISC models such as SDTM, by contrast, structure study tabulation data for review and submission. A mapping therefore does not merely translate field names; it must preserve meaning, unit, time reference, provenance and permissible value sets.
The technical availability of a FHIR element does not yet answer whether its content is suitable as a study variable. A laboratory result may include multiple measurement time points, local codes or subsequent corrections. To transfer it into a study dataset, the selection logic and the clinical context must be defined. Mapping can thus prepare the path to SDTM or to OMOP, but it does not replace the assessment of whether the source data are fit for the intended purpose.
Vulcan Real World Data as an implementation approach
Vulcan connects clinical care, clinical research and FHIR. According to HL7 documentation, the Real World Data project aims to extract data from electronic health records in a standardised format, thereby supporting research and, in particular, regulatory submissions. The official repository title describes the outcome as the “Vulcan Real World Data FHIR Implementation Guide”.
An implementation guide establishes shared rules for using a standard in a specific use case. In an RWD scenario, this can, for example, describe more precisely the diagnoses, demographic and laboratory information required for cohort identification, as well as other study data points. The mapping to CDISC nevertheless remains a separate specification: it must define which FHIR content corresponds to which study concept and how missing, ambiguous or multiple values are handled.
Distinction from eSource, EHR-to-EDC and real-world data
FHIR-to-CDISC mapping and Vulcan Real World Data are not the real-world data data type. Real-world data refers to data that may arise in routine care; the concept described here addresses their standardised retrieval and structured downstream processing. Real-world evidence only results from an appropriate analysis and must not be equated with the interface itself.
eSource and EHR-to-EDC concern the use of electronic source data or the transfer into a data capture system. FHIR-to-CDISC mapping goes beyond this from a subject-matter perspective when data are standardised for study structures and, where applicable, later regulatory data packages. However, it replaces neither the definition of source documentation nor the checks of provenance, access, data protection and data integrity.
A robust mapping starts with the study concept, not with a technical export. For each target variable, it must be decided which FHIR resource is the source, which codes are accepted, whether the original measured value or a normalised representation is used, and how temporally competing information is selected. For diagnoses, for example, it may be necessary to distinguish between a historically documented condition and a diagnosis confirmed at the index time point. Such rules belong in a version-controlled mapping specification.
The mapping must also make it clear when care data were corrected or supplemented retrospectively. FHIR facilitates standardised access, but it does not remove responsibility for checking completeness, duplicates and temporal suitability. This is particularly important when EHR data are used both for recruitment and for an endpoint: the same source may require different selection and quality criteria depending on the intended use.
Relevance for clinical trials
In studies that use data from patient records, the research question and the FHIR query must align early on. A cohort search by diagnosis, time period and laboratory value can only become reproducible if the resources, codes and filters used are documented. For downstream CDISC implementation, mapping specifications, handling of repeated measurements and evidence of the provenance of each data point are particularly important.
Full-service CROs such as Mediconomics support data flow and mapping specifications between EHRs, the FHIR interface, EDC or a data platform, and the CDISC target model. They can translate requirements from the protocol and data management into transferable study variables, align the technical handover with biostatistics, and structure the documentation for source assessment, conformity checks and reviewer guides.
Frequently Asked Questions (FAQ)
Does FHIR automatically convert data into SDTM?
No. FHIR describes the exchange of health information, whereas SDTM provides a structure for study tabulation data. Subject-matter mapping rules and checks are required between the two.
Are data from the electronic health record automatically real-world data?
They can be a real-world data source. However, for use in a study, provenance, access, relevance and reliability must be assessed for the specific purpose.
Is Vulcan Real World Data an EDC system?
No. The approach relates to FHIR-based interoperability and an implementation guide for real-world data. It does not replace an EDC system for operational study data capture.
Regulatory References
- HL7 FHIR – provides the standard framework for interoperable exchange of health information.
- HL7 Vulcan Real World Data – describes a FHIR implementation guide for the RWD use case.
- ICH E6(R3), Annex 2 – classifies the suitability and governance of real-world data for clinical trials.
