FHIR Chat · Subject type vs context in extraction

Stream: questionnaire

Topic: Subject type vs context in extraction

Jing Tang (Feb 06 2021 at 12:15):

If we already have subject type in questionnaire, can we use that as hint for definition-based extraction? I know that you can have a named context if you use the context extension. But as long as you're not extracting multiple resource for each resource type (i.e. you're not extracting more than one patient) shouldn't the subject type(s) suffice?

Lloyd McKenzie (Feb 06 2021 at 16:33):

I'm not really following. If Questionnaire.subjectType says 'Patient', how does that help you know what Patient to extract from? Same question holds if it's Practitioner or Organization.

Jing Tang (Feb 07 2021 at 11:21):

so in the case where we're extracting a new patient (or any other resource), know the type is enough?

Jing Tang (Feb 07 2021 at 11:25):

For example, if we have a questionnaire with subject type patient, and each field's definition pointing to a particular field in the patient resource, then it's clear to me how to extract a patient resource from the questionnaire response to this questionnaire even without the context extension. Maybe this is not so much a question but more of an observation... The context extension is only useful when you're editing an existing FHIR resource. Is this right? Am I missing something?

Lloyd McKenzie (Feb 07 2021 at 16:04):

You would need to have a patient in context, and the extraction process would need to understand which patient that is. E.g. If you're dealing with a mom & baby situation, is the subject for the mom or the baby? So you'd still need the context extension.