23 terms

Networking 5-1

Why use data interchange standards
To create a patient-centric EHR to aggregate data from all sites of care; sender and receiver of data may not be predictable or known in advance
Core Requirements for Data Exchange
nouns, phrases, and vocabulary & model
items we wish to communicate; typically physical things (persons, places) and actions
essential bindings between nouns; an action happens to a person; one action causes another; a person performs an action
Vocabulary & model
common definitions; assume common perspective; prescribe the nouns and phrases we can use
Choices for Data Interchange
Health Level Seven, Document Standard (HL7 CDA, HL7 CCD, ASTM CCR), DICOM, ASC X12, Prescription standards
HL7 messaging standard
the most commonly used data interchange or messaging standard used in the US today
Document Standard
a way data can be exchanged defined by a schema
used fro the exchange of images and other media such as waveforms
produces a family of standards to support the claims/reimbursement data exchange
has a set of standards that support the exchange of prescription data for ePrescribing as well as reimbursement of medication products
HL7 v2.n
- popular because it is easy to use and understand,
- and easy to implement; based on an information model;
- the messages are defined to support certain data elements that are defined through the experience of the designers for a particular event
- standard was initially created to support building a hospital information system from components from different, multiple vendors
- widely used greater than 95%
- saves money on cost of interface
- events not tightly coupled to profile
- makes no formal attempts to define process
- simplicity is its popularity
- works very well in instances when sender and receiver is known
- does not work well when receiver and sender are not connected
- not an interoperable standard
- is hierarchical, with repeating segments accommodate
- delimiter syntax was chosen to reduce the number of characters necessary to be transmitted
field separator: l
component separator: ^
repetition separator: ~
escape character: \
subcomponent: &
segment terminator: <cr>
HL7 reusable components
called segments; each segment is identified by a three-letter mnemonic; segments are content oriented; segments are used in a message depends on the message type; fields may be repeating; made up of data fields; maintains a registry of controlled vocabularies and are expressed as a triplet; limited by length as are data fields
focused on the patient, the visit, the act or event or activity or the thing
used by HL7 to express the terminology; code, text name, and controlled vocabulary identity
Use of Z
a provision made for used defined segments identified by this in the mnemonic name; good part is that user could send anything; bad thing was that users never reverted from the Z-segment to an actual HL7 standard when available
Messages are hierarchical
the message composed of segments; the segments in turn are composed of data fields, which in turn are composed of components which are further subdivided into subcomponents; the construct was delimited by a defined set of delimiters
Message header
are composed of reusable segments, each identified by a three letter mnemonic; all messages must start with a header MSH; this tells the sender and receiver, the data and time, a unique message identifier, the message type, and the trigger event, the version of HL7 v2n being used; segments used in a message are determined by message type
most flexible segment and can be used to send almost any data; with this segment supported by other segments, the entire contents of a medical record can be sent
XML delimiter
tags that only identify the segment and position in the v2.n segment; this method permits the use of XML tools to display and process the messages
Functional areas covered by v2
ADT, registration, orders, results, patient financial, query language, immunization reporting, clinical trials, adverse drug reactions, scheduling, referrals, medical records, patient care, problem lists and goals, waveforms, personnel management, clinical lab automation transactions, and master files