Topic for Consensus: Choice of Bindings

[Prescription Drug Monitoring Program]

From our 11 March WebEx:  Based on the outcome of discussion on the transport for the query use case topic, one of two topics must be pursued.

• If the consensus is a single binding, will it be HTTP or SOAP?
• If the consensus is more than one, HTTP and SOAP are obvious choices – are there others?

We would like to open the topic for comment here, and plan to discuss at our next meeting on 25 March.

[toby cabot]

Here’s an example of a binding that uses existing standards (specifically OpenSearch and hData/RHEx) to transfer patient prescription history in NCPDP XML format over HTTP.  It consists of two components: a PDMP testbed written in Ruby on Rails that simulates a PDMP serving prescription history, and a plug-in module for the OpenMRS electronic health record system written in Java.  Both are open source.

hData is what’s known as a “RESTful” style transport.  It’s very flexible.  We originally implemented both components using a Green CCDA, but when the working group reached consensus on NCPDP as a data representation, I was able to add NCPDP to the testbed in a completely back-compatible way: existing clients saw the CCDA data that they wanted to see while new clients saw the NCPDP format.  This allows old clients to co-exist with new ones so you don’t need complicated “flag day” upgrades.

The spec is https://raw.github.com/project-pdmp/spike/master/doc/srpp.txt.

You can find background info on OpenSearch at http://www.opensearch.org/, Project RHEx at http://wiki.siframework.org/RHEx and hData at http://www.projecthdata.org/ .

The code for both the testbed and OpenMRS module is at https://github.com/project-pdmp .

Comments welcome!

[Cathy Graeff]

Some of us that are nusiness SMEs but not technical may need a primer before we are able to participate in these discussions.

[Eric Hilman]

Is the question presuming a new custom transport mechanism?

I would suggest that we try to use an existing transport such as the DIRECT (www.directproject.org) standard based Health Information Exchanges (HIE) being implemented by all the states. The DIRECT standard is being promoted by ONC.  HIEs are emerging to be the embodiment of the much ballyhooed National Health information highway.  My understanding and assumptions:

• ALL EHR vendors will have an interface to HIEs to meet the requirements of Meaningful Use. ALL is a big number and wont happen soon, but eventually it will.
• While the DIRECT protocol per se is standardized now, there are still some potential variances in how to implement these.  Over the coming quarters these variances will be standardized so that a single HIE interface will work for all states HIE
• ALL providers will implement EHRs with HIE interface and be able to exchange clinical information with other providers to meet the requirements of Meaningful use.  ALL is a big number and wont happen soon, but eventually it will.
  
• Submissions to state registries such as Immunization and Cancer will happen via HIE.  This is already starting in some states.
  
• The HIE transport mechanism will include all security encryption using x.509 certificates
  
• The HIEs will support a Query model as well as Push.  The earlier implementations focus on Push.
  
• Establishing the state PDMP software as a node on a HIE to support Query will be work, but not a lot of work, since all the security and other technical issues are worked out at the HIE level. There will be web service calls to the HIE and the PDMPs must accept web service calls.  There is an opportunity to standardize this across the states.
  

So my net is that by reusing the HIEs that are already in place we minimize the work required by the state PDMP teams as well as by the EHR vendors.  We will still need the EHR vendors to add some workflow functionality to make the use of PMP much more seamless for the providers.  I can write on my vision for workflow later and in a more relevant topic. 

Eric Hilman