Saturday, May 18, 2019

Record Location on FHIR - aka Patient Identity Correlation

IHE has created
a FHIR based Patient identity management system for health information exchanges. This builds on PDQm and PIXm, by adding a Feed mechanism, and a subscription to the Feed. Added to this is a set of requirements and expectations around how Merging (Link and UnLink) are to be implemented.

The result of a Merge is that the two identities of a Patient are linked, one become master, and all the data recorded against both are considered one Patient. This means that a system implementing the Profile will treat a query request for one of the identities as if it was a query against all the linked identities. Putting the burden of link management and comprehensiveness of the query results upon the server, so that applications don't need do multiple queries to get a comprehensive patient record.

There is expected further refinement of this after Public Comment, and in coordination with HL7 Patient Administration workgroup efforts on the same topic. It is possible that a formal Merge will be supported, but in FHIR a Merge comes with some downsides. When FHIR is a front-end to a non-FHIR system (e.g. an EHR), the result will likely look like a Merge, in that only the surviving identity will ever be seen from again. Where as a native FHIR Server is used, a link is more friendly to the integrity of the data persisted in FHIR Resource form. Especially if those FHIR Resources have digital signatures on them.

What we also don't quite know is how to scale a Patient Identity Management system to a very large federation. How to keep track of communities that are behind communities (nested communities). What additional functionality that FHIR can bring to the table, what issues will appear once we start using FHIR Resources to discover the locations where Patient Data exists. It feels like this will be easy, it feels like we have learned from v2 and v3; but there is always dragons hiding.

So, does FHIR Patient Identity Management replace XCPD which is based on HL7 v3, or PIX/PDQ which is based on HL7 v3? The answer is, "Yes, eventually". But that timeframe is likely 5-15 years. That is to say that the backbone that exists today using HL7 v2 ADT, and the XCPD infrastructure is functioning and will continue to function. There is no need to rip-and-replace. However there is a STRONG need to provide more simple API into those environments for NEW partners and applications. This is where PDQm, and PIXm have been for a while. Now there is the Feed and Subscription to the Feed that this new profile brings.

So, yes HL7 v2, v3, and FHIR (four) will be used together for different endpoints. The common factor is the Patient Identity, Patient Demographics, Patient Address, Patient Phone Numbers, and other non-patient identifiers like SSN, Drivers License, Insurance ID, etc...

Thursday, May 9, 2019

FHIR Security & Privacy activities

This is an update of what is going on in Security and Privacy in, and around, the FHIR specification. 


  • FHIR R4 includes Security Considerations classification
  • SMART-on-FHIR first flavor is Normative
  • Addition of X-Provenance and X-Consent http headers
  • GDPR assessment against FHIR indicates good coverage of needs in FHIR already
  • Maturing AuditEvent and Provenance to Normative by FHIR R5
    • HL7 Implementation Guide on Basic Provenance (CDA and FHIR)
    • IHE updated ATNA to include FHIR AuditEvent feed and query
  • Signature datatype not likely to be R5 normative candidate

-----------------Details -----------------------

Overall Security Considerations:

The FHIR R4 specification now has an overall Security Consideration Classification. This spans the whole of the FHIR specification such that each Resource is assessed into one of four buckets of Security Considerations: Patient specific, Other Identified Individual specific, Business sensitive, and Anonymous Readable. These are not mutually exclusive classifications, but rather a "tendency". That is to say that each resource could cover many of these classifications, but tends to fall into the specified classification. The main goal of the classification is to raise awareness that the FHIR specification covers use-cases other than just sensitive patient data. The Security WG set the initial assessment, but the owner of the Resource can re-classify.  Also, actual use will be context specific. There is nothing wrong with using the 'Patient" classified resources in a way that is fully anonymous because they are holding synthetic data.

GDPR driven activities:

The Security WG has done an assessment of FHIR in the context of GDPR. This has produced a white paper that is available informally today. The GDPR assessment has driven some of changes that are already in the specification, and is also driving some future changes or implementation guides. These things have not really started formally yet, but include :
  • consent decision service -- to enable a FHIR Server to ask a service for Permit/Deny on an otherwise authorized request
  • basic Privacy Authorization Consent IG to support freely given and informed privacy authorizing consent
  • erasure operation to support GDPR and Right-to-Forget


The SMART-on-FHIR specification is now published in the basic form that is compatible with the original Argonaut version. This base-lines the standard at this starting point. There is interest in opening up for the next more advanced form of OAuth token support. One method uses a JSON Scope encoding, thus enabling far more comprehensive and complex scopes.

Maturity toward FHIR Release 5:

The Security Workgroup is going to work toward getting Provenance and AuditEvent to Normative by Release 5 (R5) of FHIR (Approximately end of 2020). This will be enabled by two different projects.  The HL7 Basic Provenance Implementation Guide, and IHE Audit Trail and Node Authentication updates to support FHIR. Signature datatype is not likely to go Normative in R5, but likely will have some advancements.

Plan to Mature Provenance:

The HL7 Basic Provenance Implementation Guide is getting started, so there is no specific conclusions yet. That said, the goal of this project is to define realistic and effective guidance on implementation of Provenance in a cross-organizational health information exchange (HIE) for the purpose of Treatment (may be Payment). This project is not addressing the Provenance requirements for within an organization. This project is not addressing ALL possible use-cases for Provenance, such as supporting Clinical Research. The most important part of the scope of this project is to set requirements that are as minimal as possible, yet effective for supporting Treatment. Counter this against a comprehensive Provenance implementation that would likely have well over a dozen Provenance records for any one clinical object record. Meaning that in a fully advanced Provenance it is very likely that Provenance is 10x the clinical data.  This Implementation Guide will drive public comment ballot, comment resolution, improvement of the core Provenance resource, and testing at Connectathon.  This is the maturity steps that the core Provenance resource needs to approach Normative in R5.

Note there are some Implementation Guides that have included Provenance guidance and constraints.

Plan to Mature AuditEvent

The IHE Audit Trail and Node Authentication (ATNA) project will help mature the core AuditEvent resource in support of Normative in R5. The ATNA profile is one of the oldest profiles in IHE, but has seen a major change to add FHIR based interactions. Last year there was an update of ATNA to add a query one could make of an Audit Repository to support reporting and alerting such as a report for Accounting of Disclosures, Access Log, and to support investigation of security and privacy incidents. This year IHE has added a AuditEvent feed support to support FHIR based applications recording AuditEvents using http RESTful FHIR create. Thus now the ATNA profile has support for recording an AuditLog, and queries.  This is going through a Public Comment ballot in the coming months, and will be setup for testing at IHE Connectathon in the future.

Advancements since R4

Provenance has not changed much yet, although there is a related abstract Provenance service ballot going through the HL7 ballot process. This abstract Provenance service work may impact the FHIR Provenance resource, but no changes have yet been proposed.

Provenance X-Header:

In FHIR R4 there is a new capability that may not be as well known. When an app is creating a FHIR Resource (for example an Observation), that application likely has a very rich understanding of the context of the creation event, so could provide a Provenance. The historic way it could do this was to either create the Observation, then create the Provenance; or it could use a Transaction to send a Bundle with both the Observation and Provenance. These do work, but there is a question of making this more easy. So there is now a http "X" header that one can use in a simple RESTful create/update to also carry the Provenance. Thus a normal http RESTful create of a new Observation can carry the app's definition of the Provenance in the http header, while the Observation is in the body. 

Consent X-Header:

A joint effort with CBCP has moved to add an X-Header to support an app asserting that a FHIR Consent authorizes the request being made. This is a http "X" header that holds the URL to the FHIR Consent. The Server is not obliged to consider the Consent, but it may consider it. That is to say that the use of this "X" header will only enable actions that the access control protecting the data also agrees with. The prime use-case for this feature is to enable a real-time point-of-care capturing of a Consent from the patient that authorizes the interaction. Where prior to having this Consent, the request would be rejected, but with appropriate proof that an informed and freely given Consent would now enable access. A similar "point of care consent" interaction is supported in some Nationwide Health Exchanges such as CareQuality.


The Signature datatype is receiving some interest. Given that the primary function of a digital signature leverages external Digital-Signature standards such as XML-Signature and JSON Signature. Thus we are not developing the technology of Digital-Signature. In the FHIR Signature Datatype, we are just exposing in a more friendly FHIR way some of the useful attributes about the signature. The Digital-Signature validation is done using the Digital-Signature standard. A new use-case that is driving some interesting new views is one that has a context of a Provenance "Service" that is managed independently from the Clinical repository. In this case a end-user may be using a clinical Resource and use a Provenance Service to discover the Provenance of that clinical Resource. In that case the Provenance is being managed independently from the clinical Resource and the pathway the clinical Resource was communicated; then the Provenance.signature does not need to be a non-repudiation, but can be a simple integrity check (e.g. sha256). See other issues on Signature

Monday, May 6, 2019

IHE ITI Spring 2019

Updated with Public Comment details available here

The IHE ITI, PCC, and QRPH workgroups met in OakBrook, IL this week at the RSNA Headquarters. We still are not meeting in Treviso Italy., but we have heard that the July meeting will be in Sardinia Italy. Right before the big tourism time. Specifically we will be at the Facilities of Sardegna Ricerche at Polaris, Parco Scientifico e Tecnologico della Sardegna, in Pula (CA), Italy. Great time to join IHE and have your company send you to the meeting.

The ITI committee this week finished up one small supplement on adding Facility support to the Mobile Care Services Discovery (Provider/Services Directory). This updates the version from last meeting. 

We approved for Public Comment three brand new Supplements

  1. Adding a FHIR AuditEvent feed capability to the ATNA profile. Thus the ATNA profile would now include a Query on AuditEvent to support reporting and alerting applications, and now a Feed (RESTful Create) of AuditEvent to support applications recording audit events.  This work item also updated the Query to FHIR R4, so this supplement is focused on FHIR R4. There is now good bi-directional support for the original DICOM Audit Message schema, and the FHIR AuditEvent. This gives applications flexibility on how they record auditable events. They can use:
    • UDP Syslog - DICOM XML schema
    • TLS/TCP Syslog - DICOM XML schema
    • http/REST - FHIR JSON AuditEvent
    • http/REST - FHIR XML AuditEvent
  2. Adding support to XCA for a deferred response mode to support responding organizations that need significant time to complete a request. For example where a responding organization holds large quantities of historic paper records, which they will make available, but want specific patient request to trigger them scanning and indexing that data. In this way they can receive a request for a specific patient, they can respond that they do have data, but need a day or week to complete the request, then as they scan the data they can feed the data back in bunches.  This work is similar to a deferred mode in XCPD, and much of the technical work was done many years ago in a white paper by Karen.
  3. Creation of a FHIR based Patient identity management system for health information exchanges. This builds on PDQm and PIXm, by adding a Feed mechanism, and a subscription to the Feed. Added to this is a set of requirements and expectations around how Merging (Link and UnLink) are to be implemented. The result is that when two identities of a Patient are linked, one become master, and all the data recorded against both are considered one Patient. This means that a system implementing the Profile will treat a query request for one of the identities as if it was a query against all the linked identities. Putting the burden of link management and comprehensiveness of the query results upon the server, so that applications don't need do multiple queries to get a comprehensive patient record.
I am confident of the text we are sending to Public Comment, but I also expect that there is a significant amount of experience we need to gain before these become final specifications. That there will be more clarifications needed based on Trial Implementation, and the use-case that drives constraints will become more clear.

There are three very short webinars by the three editors of these Public Comment versions of their supplements. In these webinars they explain the use-cases that are being addressed, how they are addressed, and specific open issues we would like the Public Comment to help us with.

Thursday, May 2, 2019

The Graying, Retirements, and Renewal at Integrating the Healthcare Enterprise (IHE)

I have been involved with IHE for 20 years. So I likely am one of the 'elders'. I am graying, but not yet close enough to retirement. However this is not the case with many that were here when I first started.

The sad news is that many of the people that started IHE, and were core to the first 20 years have retired, or have been moved to new jobs that keep them from participating in IHE. Amazing resources like Ben, Charles, Elliot, Elliott, Harry, Karen, Ken, George, Gila, Manuel, Mark, Rob, etc...

The good news is that there is room at the table for new people. IHE needs and would welcome participation. You can get involved FREE by just subscribing to the mailing lists, this gives you much of the accessibility, and you CAN make contributions. However you really should JOIN, which is also not that expensive. As a member you have voting rights, can promote profile opportunities of your own, and feel good at being a member.  See the IHE Participation details.

IHE it-self is now 20 years old, so it is now reaching a maturity level that is beyond up-start. This does not mean it is irrelevant nor without improvements. IHE has been moving toward Profiling FHIR, using online publication creation tools, using GitHub, and providing a more mature Connectathon platform. The biggest change that we are attempting this year is to switch away from a annual cycle, to a continuous Profile development cycle. This enables us to work on smaller and larger projects than the annual cycle enables.

IHE is not what it was before, so please engage and help move Healthcare IT standards along. The need for IHE Profiles (aka, Implementation Guides) is critical to success of Interoperability. Standards alone are not sufficient, as they must include support for ALL use-cases. The point of an IHE Profile (Implementation Guide) is to look at a specific (yet reusable) use-case and constrain the underlying standard, fold in vocabulary, set trigger events, and set expected behaviors.

Most important fact about Standards and Profiles --> They enable everyone to set a baseline of known functionality, and build on-top-of-that. Specifically they enable things that can't be done without Interopeability. The Interoperability layer is not a feature, it is an enabling technology.

Please consider engaging with IHE.