minimal Common Oncology Data Elements (mCODE) Implementation Guide
1.16.0 - STU Release 2 (Ballot Version)

This page is part of the HL7 FHIR Implementation Guide: minimal Common Oncology Data Elements (mCODE) Release 1 - US Realm | STU1 (v1.16.0: STU 2 Ballot 1) based on FHIR R4. The current version which supercedes this version is 2.0.0. For a full list of available versions, see the Directory of published versions

CodeSystem: mCODE Catch Codes

Usage

This code system contains codes that are required to achieve positive identification of FHIR instances. The need for positive identification stems primarily from the need to associate instances with slices in the mCODE Patient Bundle. Positive identification is also useful in search, for example, to retrieve all Condition instances that represent PrimaryCancerConditions.

To understand the need for this code system, consider a FHIR Condition. Condition.code is the primary identifier of the condition. The association with a particular profile depends on the value set bound to Condition.code in the profile. A Condition is a PrimaryCancerCondition for the purposes of mCODE if its code comes from the value set PrimaryOrUncertainBehaviorCancerDisorderVS.

On the other hand, if Condition.code does not come from that value set, we cannot automatically conclude the instance is not a PrimaryCancerCondition. It depends on the value set binding strength. A binding strength of extensible, preferred, or example allows other concepts, so if the Condition.code is not in the defining value set, we cannot determine if the instance is or is not a PrimaryCancerCondition 1. This inference is possible only if the binding is required.

This limitation makes required bindings highly preferable. However, there can be legitimate reasons for extensible value sets. Some value sets are intrinsically open, for example, the set of human disorders. New disorders (and new designations for existing disorders) come along, a lesson richly learned in 2020.

This brings us back to the current code system. These codes make it possible to use required bindings by creating an “Other, specify” choice. Since each code is unique to a specific value set, when one of these codes is encountered, the instance can be positively identified. An associated invariant forces the user to specify an additional code, so the semantics of “other” are not dependent on the other choices in the answer set.

  1. It is possible that some additional, exogenous information could allow this conclusion to be drawn. ↩

Summary

Defining URL:http://hl7.org/fhir/us/mcode/CodeSystem/mcode-catch-code-cs
Version:1.16.0
Name:CatchCodeCS
Title:mCODE Catch Codes
Status:Active as of 2021-04-15T12:44:45+00:00
Definition:

Codes needed for positive identification of certain types of instances, more specifically, to uniquely associate instances with slices when they are used in bundles. The codes in this code system are used when a concept falls outside of the defined set of codes. They make it possible to use 'required' bindings where 'extensible' bindings would result an instance matching multiple slices and thus trigger validation errors.

Publisher:HL7 International Clinical Interoperability Council
Content:Complete: All the concepts defined by the code system are included in the code system resource
Source Resource:XML / JSON / Turtle

This Code system is referenced in the content logical definition of the following value sets:

This code system http://hl7.org/fhir/us/mcode/CodeSystem/mcode-catch-code-cs defines the following codes:

CodeDisplayDefinition
PCC-OTHER Other Primary Cancer Condition, SpecifyCode to be used when the desired concept is not represented base value set. This code represents the equivalent of 'Other, specify: _________'. Specify the additional concept as the second coding.
SCC-OTHER Other Secondary Cancer Condition, SpecifyCode to be used when the desired concept is not represented base value set. This code represents the equivalent of 'Other, specify: _________'. Specify the additional concept as the second coding.
TMT-OTHER Other Tumor Marker Test, SpecifyCode to be used when the desired concept is not represented base value set. This code represents the equivalent of 'Other, specify: _________'. Specify the additional concept as the second coding.
CD-OTHER Other Cancer Disorder, SpecifyCode to be used when the desired concept is not represented base value set. This code represents the equivalent of 'Other, specify: _________'. Specify the additional concept as the second coding.