Years ago at Baystate Health we proposed putting health questionnaires on the patient's own device. Watching Lloyd McKenzie's SDC talk years later, I realized I was looking at the same problem.
The problem, stated once. Back when I worked at Baystate Health, we got accepted as a Cerner/Oracle Code App Challenge finalist with a simple proposal: use a consumer's personal device to securely receive, complete, and exchange health questionnaires and forms. The demo is still on YouTube (linked under sources). The friction was not "can we build a form UI" — it was getting structured answers back into the clinical and administrative systems that needed them, without another fax or portal dead-end.
What SDC actually standardizes now. FHIR Structured Data Capture (SDC) is the Implementation Guide that turns that problem into a wire contract: Questionnaire defines the form, QuestionnaireResponse carries the answers, and the IG layers on pre-population from existing patient data, expression-based enablement and calculation, and the $populate / $extract operations that move answers into other FHIR resources. The standard has come a long way since that challenge pitch. Watch Lloyd McKenzie's Intro to FHIR SDC (also under sources) for the walkthrough that made the lineage obvious to me.
Where it shows up in the mandate stack. Da Vinci Documentation Templates and Rules (DTR) is SDC wearing a prior-auth hat: payers ship adaptive questionnaires so providers collect exactly the evidence a coverage decision needs. Dynamic pick lists that depend on earlier answers live on the parameterized-valuesets card — that machinery is evaluated under SDC rules inside those questionnaires. The same "get structured evidence back" pressure shows up again in the attachments mandate path; that story is its own card, not this one.
What ImOnFHIR does with it: the FHIR Analysis Workbench's DTR panel already extracts questionnaires from DTR libraries so you can see the form shape the payer actually shipped — that is this card's Lab door. We point at the SDC and DTR IGs; we do not host a questionnaire renderer or claim live DTR execution here.
The standard has come a long way. My family's pronunciation of "idea" has not.