High-Level Standards Landscape

HL7V2 Pros and Cons:

The HL7 V2 Messaging standard has been used for communicating laboratory data for decades. The V2 base standards are in “maintenance” mode according to HL7. While reliable and common, there are known limitations of V2, such as there is no underlying information model, optionality is ubiquitous and poor support for controlled vocabularies. As a result, it may be less amenable to innovation and flexibility that will be required in an innovative, patient facing platform such as that represented in this initiative. Nevertheless, simple fields needed for communication of at-home Covid testing are present and have been identified (see below). In addition, local, state, and territorial agencies may be more prepared to accept V2 messages than FHIR at this time.

The HL7 Version 2.5.1 Implementation Guide: Electronic Laboratory Reporting to Public Health, Release 2 (US Realm) from 2014 was examined to support the identification of V2 fields.

FHIR Pros and Cons:

Fast Health Interoperabilty Resources (FHIR) is HL7’s newest standard. FHIR has been rapidly developed and adopted with much enthusiasm from standards designers, developers and implementers because it is easily implemented and has a lower bar for developers. It is flexible; base resources can be used as-is or adapted as needed.

When coupled with Substitutable Medical Applications, Reusable Technologies (SMART) APIs, apps for any use case can be rapidly developed and implemented. Once built, apps can be launched across many health systems. These apps are/can be both patient or provider facing: Patients from different health systems can use a consumer single app, or providers can use a business app running within the EHR with minimal modifications.

FHIR app functions can be seamlessly launched directly from EHRs, even those developed externally to the EHRs. There are some negotiations and agreements to be made with the EHRs but this will likely become easier over time especially with information blocking rules. Most importantly for this use case FHIR apps have a great future for patient data access and patient empowerment.

FHIR has limitations. It provides a generic structure for communicating data which requires specific constraint for different use cases. The same data mapping and terminology implementation and maintenance challenges exist as exist with Consolidated Clinical document Architecture (C-CDA) and V2. In addition, though FHIR has been implemented across all major EHRs, the degree to which FHIR supported functions are generally available in implemented (sold) EHR software is variable and not fully known.

References

• HL7 FHIR US Core IG
• HL7 US Core Lab Observation
• How to Report COVID-19 Laboratory Data
• Electronic Laboratory Reporting to Public Health, Release 2 (US Realm) from 2014
• Association of Public Health Laboratories Covid Response
• LOINC
• SNOMED CT
• CDC on At-Home Testing
• Extended Operations on the RESTful API
• SANER
• Logica COVID-19 FHIR Profile Library IG

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