Software Partners has long recognized that small, agile web services will increasingly supplement and replace large, expensive integrated applications.  (See The Future of IIS.)

We therefore have produced web service products that can be assembled together to create a complete healthcare workflow.  As building blocks of Service Oriented Architecture (SOA) for Healthcare, these web services can also be used to extend existing medical software systems such as Immunization Registries.  The first three products are directly aimed at the three most basic components of any healthcare workflow:

• Identity Resolution, traditionally known as Master Patient Index, or eMPI 
• Health Data Retrieval and Update, to create a Patient Profile or Continuity of Care Document (or Record)
• Computerized Decision Support, to complete the profile with quality measures, alerts, and so forth.
  

The next three Section Headings on the menu above describe those three products in more detail.  The big picture of how they fit into SOA can be visualized like this:

It is essential, when we are trying to create re-usable software components, that we define and adhere to standards, so that the separate pieces will work seamlessly with each other, and with components produced by other vendors. For this reason, we place great emphasis on published Standards, as described in more detail in the final Section in the menu above.

Standards are important in a number of aspects of software engineering and SOA, including:

• Operation Semantics - how do we identify Johnnie versus Jimmy
• Vocabulary - what do we mean by "Patient", by "Disease", by "Encounter", how do we indicate influenza versus measles  
• Interfaces - to use an electrical cord analogy, making sure the "plugs" fit the "sockets" to connect the pieces together

Example

The Interoperability Showcase at HIMSS09 presented an example of multiple systems working together to accomplish several tasks related to immunizations of a child over a period of time, which will be described in more detail below.

    [click here to open the diagram in a separate window]    

The scenario in the diagram shows IHE (Integrating the Healthcare Enterprise) standard interactions between multiple systems during 3 separate medical encounters.

1. 1. An eighteen-month old child is brought to a clinic for a routine checkup.  This child had not visited this clinic before.
2. 2. The same child, now 5 years old, is brought to a different clinic in another state for a routine checkup.
3. 3. This same child is registered for kindergarten, and needs an immunization "yellow card" before being allowed to register for school.

In the first visit, the PCP (Primary Care Provider)'s system might need to do several things. Not all of these steps are shown in the diagram above, and the steps might vary depending on

• the presence or absence of a RHIO (Regional Health Information Organization), or
• whether a PIX (Patient Cross-Reference) Manager (aka Master Patient Index or MPI) is associated with the RHIO, or the State IIS (Immunization Information System), or only with a local EMR (Electronic Medical Record) system.

1. 1. Register the patient and assign a local patient ID.
2. 2. Submit the new patient record to the State IIS's PIX Manager.
3. 3. Query for a Global Patient ID from the State IIS's PIX Manager.
4. 4. Query for Existing Data from the State IIS using the Global Patient ID.
5. 5. Request Decision Support from an Immunization CDS (Computerized Decision Support) System, using data returned from the State IIS, along with any additional medical information gathered at the PCP.
6. 6. Administer the necessary shots.
7. 7. Update the State IIS, which forwards the medical data to an XDS (medical document repository and registry) in the RHIO.
   

At the completion of this encounter, several tasks have been accomplished:

• The controlling PIX Manager knows about the local ID for the patient, and has assigned a global ID.
• The PCP has located and received any previous immunization data for the patient.
• The child has been immunized.
• The State IIS has been updated with the new shots.
• The controlling EMR or RHIO for the PCP has received the updated medical record.

• the presence or absence of a RHIO in the new state, or
• whether a PIX Manager is associated with the RHIO, or the State IIS, or only with a local EMR system.

1. 1. An authenticated PH (Public Health) Nurse queries the HIE (Health Information Exchange -RHIO) 2. by patient name and dob,
2. 3. PH Nurse selects the matching record (more than one possible match may be listed).
3. 4. PH Nurse queries for Immunizations using the matching record.
4. 5. PH Nurse requests a validated shot record from Immunization CDS.
5. 6. PH Nurse requests that Yellow Card be printed from validated shot record.
6. 7. Parent is given yellow card and child is admitted to school.