Should value[x] appear as a sliced array?

[markkramerus]

http://build.fhir.org/ig/HL7/us-breastcancer/StructureDefinition-oncology-BreastCancerHistologicGrade.html

I wonder why I see value[x] as a sliced array, and also right below it, valueCodeableConcept. I would think only the latter is necessary. See illustration.

[cmoesel]

So... this is as designed. Here are the relevant CIMPL definitions and mapping rules:

(1)

BreastCancerHistologicGrade is (eventually) based on EvaluationResultRecorded, from which it inherits the EvaluationResultTopic field.

Element:    EvaluationResultRecorded
    // Snipped out fields not pertinent to this issue
    StatementTopic is type EvaluationResultTopic

(2)

EvaluationResultTopic has the following Value:

Element:    EvaluationResultTopic
    Value: 0..1 (Quantity or CodeableConcept or string or boolean or Range or Ratio or time or dateTime or TimePeriod)
     // Snipped out fields not pertinent to this issue

Note that it is a choice of many types.

(3)

In BreastCancerHistologicGrade the CodeableConcept choice of the value is constrained to the NottinghamCombinedGradeVS value set:

EntryElement:   BreastCancerHistologicGrade
    // Snipped out fields not pertinent to this issue
    EvaluationResultTopic.CodeableConcept from NottinghamCombinedGradeVS

This is the key point. This constraint is applied to the CodeableConcept in the choice. It doesn't say the choice can ONLY be CodeableConcept. Instead, it says that if you choose a CodeableConcept, it better be from the NottinghamCombinedGradeVS value set.

(4)

EvaluationResultTopic.Value is mapped to value[x] here:

EvaluationResultRecorded maps to http://hl7.org/fhir/us/core/StructureDefinition/us-core-observationresults:
    // Snipped out mappings not pertinent to this issue
    EvaluationResultTopic.Value maps to value[x]

So, the entire choice gets mapped to value[x], one of which is the CodeableConcept with a VS binding. This results in a slice in the profile because that's how we constrain an element in a choice without disallowing the other choice options.

(5)

If you don't want this, then I think you need to add the following additional constraint to BreastCancerHistologicGrade (or one of its parents):

EvaluationResultTopic value is type CodeableConcept

[markkramerus]

Solution is then to have "EvaluationResultTopic value is type CodeableConcept" where the value should be constrained to a CodeableConcept. I'll do that where needed.

[markkramerus]

Fixed in Oncology observations. Should be free of slicing now. I hope!
Leaving open until this is confirmed in the IG.

[cmoesel]

Confirmed free of slicing on build.fhir.org.