From detailed guides to online courses – resources are available to provide you with the knowledge necessary to build and integrate EHR applications.

Message and Document Standards

When systems need to communicate with the EHR, they will usually use an integration pattern called messaging, transferring information frequently and immediately. The term message refers to a unit of information that has to be moved between systems. Messaging standards define the format and construction of the message that will be used to convey the information. 

Messaging and document standards include:

HL7 v2 Messaging

The HL7 version 2 messaging standard, perhaps the most widely implemented standard for health care in the world, allows for the simple exchange of clinical data between systems. It defines both the transport and messaging standards to convey information. Support for terminology standards also exists but is not rigorously defined. Although not as complex or complete in functionality as other standards used in healthcare, legacy systems using this very common standard will be around for a while. 

HL7 v3 Messaging

In response to difficulties with lack of clarity in the HL7 v2 standard, HL7 created a new standard based on a strict modeling methodology and XML encoding, with robust built-in support for terminology. HL7 v3 uses a single information model – the Reference Information Model (RIM) – providing a consistency lacking in HL7 v2. Unlike HL7 v2, it is less a framework for negotiation, and more of a solid specification, reducing the amount of custom work needed to connect two systems.

HL7 v3 Clinical Document Architecture (CDA)

A clinical document can be described as anything found in a health care client’s medical record that describes something about their health or their care. They are used extensively throughout health care to provide two main functions – to communicate information between clinicians about the health of the client, and to maintain a permanent record of their care to support compliance with local regulations and laws. The clinical document architecture is a framework based on the HL7 version 3 RIM, vocabularies and data types that allow one to express clinical documents in a human-readable and machine-readable form. 

Digital Imaging and Communication in Medicine (DICOM)

Medical imaging generates vast amounts of data, using a very large array of imaging technologies. DICOM is the standard to create, store and transmit medical images and associated information between systems. The DICOM standard is comprehensive and defines all standards necessary to exchange images, including hardware specification, transport protocols, messages, content and document standards, and vocabulary and terminology sets. 

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