Healthcare Technology: Healthcare Interfaces 101

Interfaces Defined

Webopedia defines an interface as a boundary across which two independent systems meet and act on or communicate with each other.

One familiar type of an interface is a user interface, like a keyboard, mouse, etc. which allows a user to interact or communicate with a computer’s operating system. So between the user and the operating system is a keyboard that allows that communication to take place.

There are two basic kinds of interfaces: a hardware interface and a software interface. A hardware interface consists of the wires, plugs and sockets that hardware devices use to communicate with each other. A software interface on the other hand is the language and codes that the applications use to communicate with each other and with the hardware.[1]

In all the examples above, the key function of the interface is to serve as the bridge or connections between two INDEPENDENT systems, applications or hardware devices that enables communication or messages to be passed between them. For our purpose, we will be focusing on software interfaces specifically within the healthcare industry.

Why Interfaces Exist

Interfaces exist in various industries for the same reason of being a boundary between disparate systems. In healthcare, for example, the need for interfaces is even more pressing because healthcare facilities use a variety of software applications or information systems from different vendors. There are numerous vendors, data providers, and custom applications that need to exchange information using evolving standards. Because these applications or systems are created by different software vendors, they cannot communicate with each other and therefore need a way to exchange data. This exchange of data between disparate applications or systems is achieved through the use of an interfaces or healthcare interface engines. Healthcare interface engines connect applications by mapping and transferring data between the applications using standards and data definitions understood by each application. Interoperability or the ability for two systems to exchange data has been a key bottleneck in healthcare organizations. Interface engines have come about to resolve that issue.

Healthcare Messaging Standards

There are many standards in healthcare, with a diverse range of protocols and types of data. There are different health information systems such as labs, pharmacies, clinics, hospitals, and many others. For an electronic medical record system, for example, to transmit lab orders to a lab system and receive results back into the EMR, an interface is required. For these two systems to exchange data, they must adhere to a standard or agree on a common protocol or data formats. Examples of such standards are HL7 for Health Level 7, XML or Extensible Markup Language and CCD or Continuity of Care Document.

Health Level 7 (HL7) is the most widely used messaging standard in the healthcare industry. "Level Seven" refers to the seventh level of the International Organization for Standardization (ISO) seven-layer communications model for Open Systems Interconnection (OSI) - the application level. The application level interfaces directly to and performs common application services for the application processes. [2]

XML is similar to HL7 except that unlike HL7, XML is web based. CCD on the other hand, is used to exchange clinical documents like in health information exchanges or HIE.

Directions of interfaces

There are two basic directions an interface may take. An interface may be implemented to go in one direction or unidirectional or to go in both direction known as bidirectional. As I alluded to earlier, a physician practice may want to submit lab orders electronically to a hospital or other lab systems and receive results electronically back into their EMR system. That is an example of a bidirectional interface. Alternatively, a physician practice may print orders and give to their patient to physically take to the lab and the results can be sent electronically back to the physician practice. In that case, it is a unidirectional or Results only interface. Depending on a variety of factors not limited to workflow or budget, a practice may implement a unidirectional or bidirectional interface. A unidirectional interface can either be outbound or inbound relative to a given system.

Kinds of Interfaces

There are also many kinds of interfaces in healthcare. One example is a practice management interface and this include demographics or ADT (Admit Discharge and Transfer Message) interface, Scheduling or SIU (Scheduling Information Unsolicited) interface and Charges or DFT(Detailed Financial Transactions) interface. There can also be a Lab/Rad Orders or ORM (Order Message) Interface, Lab/Radiology ORU (Observation Result Unsolicited Message) interface, Progress Notes interface, Electronic Health Exchanges (eHX), among several others.

Flavors of PM Interfaces

Depending on the need of the organization, it will request a particular type or kind of interfaces and a particular flavor of a given interfaces. Take practice management (PM) interfaces for instance. A demographics or ADT interface can either be inbound, outbound or bidirectional depending on the organization’s workflow, needs and the systems involved.

There are some healthcare organizations that have been using a certain practice management system for patient registration long before they acquired an EMR. As a result, the organization may decide to continue patient registration in one system and document their progress notes in another system-the EMR. In that case there need to be a flow of patient demographics from the PM system to the EMR. Normally the PM system and the EMR are by different vendors and therefore an ADT Outbound (with respect to the PM system) interface is required to facilitate the exchange.

The same system in which patients are registered is best for scheduling (although not mandatory) and so when appointments are created in the PM system, a Scheduling or SIU Outbound interface is required to transmit patient schedules to the EMR system.

Depending on which system is used for billing, let’s assume the PM system is used for billing, progress notes are documented in the EMR entering assessments, treatments and charges. In such instance, a DFT or Charges interface is required to send charges from the EMR back to the PM system. The scenarios described above can be summarized and normally implemented as ADTout, SIUout and DFTin Interface. See diagram below: