HL7 CDA R2 AIS Implementation Guide

HL7 Additional Information Specification Implementation GuideCDAR2AIS0000R0303.7.16 General Timing Specification (GTS) Data Type.The GTS data type is used for elements that describe the time of administration of a therapy orother service. Where an attachment describes a complex regimen or a planned use of amedication, the required information pattern can be very involved. Many sending systems andreceiving systems do not have the functional depth to generate or interpret such messages. This isparticularly burdensome on receiving systems when processing an attachment that is regulated byHIPAA because, under HIPAA regulations, there should not be companion guides or tradingpartner agreements that would exclude the use of specific options. Therefore each receiver mustbe able to handle the most complex GTS expression that a sender can create.Accordingly, HL7 has adopted a constrained specification for elements using the GTS data typewhen creating attachments in the computer-decision variant. As always, elements that describeGTS values in the computer-decision variant shall include human-readable text that describes theinformation. For very complex regimens the human-readable text is the only way that theinformation can be sent.3.7.16.1 GTS in the Human-Decision VariantIn the human-decision variant where the answer that is called for is assigned the GTS data typethe sender shall send a natural language phrase that gives the timing of the service. It ispermissible to use abbreviations that are commonly used in writing prescriptions such as QD andBID. For example:2 puffs BID for 30 days3.7.16.2 GTS in the Computer-Decision VariantAs usual, in the computer-decision variant the sender shall also include a natural languagephrase that describes the content. For very complex regimens that cannot be expressed using therestricted GTS data type, the natural language description of the regimen shall be the only way inwhich the information is described.The GTS data type is most often used with the element, but can be applied toother elements as well. A GTS in HL7 Version 3 is a sequence of timing specifications, whichcan be intersected to produce the final timing.This implementation guide restricts the use of the GTS data type as follows:• The first element shall be of type IVL_TS, and shall either indicate thestarting and ending points in time over which administration occurs, or indicate theduration when starting and ending points are not known. For example, the followingindicates duration of 10 days, starting on August 12, 2006:• When the start date is not known the representation shall only include a element,with the time unit represented using UCUM. For example, the following shows aduration of 10 days:Page 66March 2007Copyright © 1998-2007Health Level Seven, Inc. All rights reserved.Release 3.0 Draft Standard