Information Exchange Patterns

I haven't written for awhile. I started working part-time last month and I also went to two out-of-town meetings. I found that working part-time takes a lot of energy; much more than I expected. I have wanted to write about information exchange patterns. The problem I have found is that it is hard to understand the different patterns of information exchange. I have been listening in on a lot of HIT Policy Committee NHIN workgroup discussions. Nevertheless, my confusion has only grown. I will try to present an overview (according to my understanding) of the two basic types of health information exchange below.

I think the concepts of information exchange are easier understood at the high level than when you get into the details. In my mind, there are two characteristic types of information exchange-those that take place on a point-to-point basis and those that require networks with their associated intermediaries. Of course, this is over-simplified. Consider the point-to-point exchange we are all familiar with--email sent over the Internet. Even though I write a message and send it you, the email does not travel directly from my computer to yours. Rather, it is forwarded through a number of intermediate servers on the Internet backbone. My message could potentially be intercepted and even altered before you receive it. Obviously, this is not acceptable for the transmission of protected health information. The NHIN Direct Project is trying to solve problems with point-to-point information sharing for small medical practices.

Point-to-Point Sharing

The exchange pattern in this type of information comes in two flavors-send/receive and request/respond. Two examples should help clarify this exchange. A primary care physician is referring a patient to a specialist for a consultation. The primary care physician SENDS a CCD summary document to the specialist who RECEIVES the clinical summary. This information exchange is important for patient care because it is used to help facilitate a transfer of care. Studies have shown that traditional handoffs using paper records are high risk areas for important patient safety and quality information to be lost. This has been designated a priority area for meaningful use under ARRA. Some other examples of use cases for this type of exchange are: 1) a lab sends results to the ordering clinician, 2) a clinician sends an electronic prescription to a pharmacy, and 3) a hospital sends a patient discharge summary to the attending physician, and 4)a patient contacts their PCP with a question about their current medications.

Now suppose the specialist's staff check the next day's schedule and notice that the doctor is due to see a referral patient from a primary care clinician but they have not received any clinical information about the patient. They can REQUEST the information from the primary care clinician who hopefully then RESPONDS by sending a patient summary and a copy of the document explaining the reason for referral.

Basic requirements for these types of exchanges are a secure channel for message transmission because protected health information is to be transferred. The exchange is not secure if a traditional Internet connection is used (like http, for example.) But standards do exist that enable secure information exchange on the Internet through use of existing infrastructure. Greater security could be provided by encrypting the data in transit and/or using digital signatures to assure identities of the two parties and to make sure that the data is not altered in transit. The sending party has to "know" the address of the recipient and should verify that the information is being sent to the intended party. Many privacy advocates would inject consent issues into even this simple type of exchange. Current federal law-HIPAA-allows exchange without patient consent for treatment, payment, and health care operations purposes. Only the minimal necessary data should be sent. Complex governance structures and highly granular consent options are not usually envisioned for these types of information exchange, however. Point-to-point exchange is expected to meet many of the 2011 Stage 1 meaningful use requirements.

There are some problems with this type of exchange. Many small offices will not keep their systems available online 7/24/365. A longitudinal record
could not be exchanged easily using this method. Patient and provider directory services are not available.

Network-based Exchange

Network-based exchange usually occurs via a query/retrieve format. This is often a multistage transaction. The first, query, step might be- Do you have information on patient X? In the second step, the responder performs a registry search. Then the response might be- yes, we have CCD from dates a,b,c, lab results from dates a, d ,f, x-rays from dates g, h, i. The third step would be for the requestor to ask for the specific information (stored in one or many repositories.) The final step would be for the responder to retrieve the information and send it to the requestor.

The network-based exchanges may also support subscribe/publish services. This is similar to RSS feeds you are already familiar with. For example, a primary care physician may subscribe to a service that provides a notification any time new information for his/her patients x,y, and z is posted on the exchange. When patient x goes to the ED on Saturday night, information for that encounter would automatically be available in the doctor's office on Monday morning.

This type of exchange depends on a complex infrastructure of policies, services, and standards. There usually is a master patient index, registries, repositories, secure transport standards, authentication and authorization for exchange users, and a trust framework for how the data/information will be used, by whom, for what purposes. For example, participants in NHIN Exchange pilot projects have all agreed to use a DURSA- data use and reciprocal support agreement. Other services such as data aggregation, anonymization, and reporting functions might also be offered. Some form of networked health information will probably be needed to meet Stage 2 and 3 requirements for meaningful use. (The requirements have not yet been specified by ONC.)

John Moehrke has covered some of these issues in blog postings on Monday and Wednesday of this week. See his commentary.