Introduction�to �FHIR SDC

Lloyd McKenzie, Dogwood Health Consulting

Organized by

FHIR® SDC Conference

June 2025

About Me

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• One of FHIR’s 3 initial editors
• Co-chair FHIR-Infrastructure
• Past chair FHIR Management Group
• HL7 Fellow
• Lead for both the ONC and international FHIR SDC projects

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Chief Standards Officer

Dogwood Health Consulting

Lloyd McKenzie

This presentation

• Is licensed for use under the Creative Commons, specifically:
• Creative Commons Attribution 3.0 Unported License
• Do with it as you wish, so long as you give credit

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• These slides include content from Brian Postlethwaite
• With updates by Lloyd McKenzie

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FHIR® SDC Conference | June 2025

What is Structured Data Capture (SDC)?

• Standardize/enhance capabilities of FHIR Questionnaires:
• Workflow
• Complex form rendering
• Complex form behavior
• Automatically populating forms
• Automatically extracting data from completed forms
• Adaptive forms
• Modular forms
• Form derivation

FHIR® SDC Conference | June 2025

Complex workflow

• How do you find a form?
• How do you retrieve allowed values?
• How do you manage form completion?
• How do you submit a form?
• How do you ask someone to complete a form?
• How do you track whether they’ve filled it out?
• How do you derive one form from another?

FHIR® SDC Conference | June 2025

Complex form rendering

• Have questions/instructions render the way you want
• Pick at least one green option and no more than one red option
• How are you feeling today? is “great”, is “horrible”
• Hide or mark certain questions as ‘read only’ (e.g. calculated score)
• Should questions be a grid or table? Should a question use a dropdown? Checkboxes? Radio buttons?
• And within that, how wide should columns be, what should column headings be, what should the steps on a slider be, etc.
• Additional display guidance.
• Social Security number:

nnn–nnn-nnn

FHIR® SDC Conference | June 2025

Complex form behavior

• EnableWhen questions based on expressions
• If the total score from group 1 > 30, then display these additional cardiology questions
• EnableWhen options
• Only display “pregnancy” in “reason for absence” if gender = F
• Constraints
• Can have a maximum of 2 questions with an answer of “most preferred”

FHIR® SDC Conference | June 2025

Complex form behavior (cont’d)

• Constrain values
• 5-10 characters
• January 1-March 30
• YYYY-MM
• Must be a JPG or PNG, < 500KB
• Must be lb or kg
• Minimum 3 choices, maximum of 5

FHIR® SDC Conference | June 2025

Complex form behavior (cont’d)

• Constrain references
• Answer must be Condition or “Diagnosis Observation”
• Possible answers are: Observation?patient=$patient.id&code=12345-5&…
• “Click here to create a new value” (launches new questionnaire)

FHIR® SDC Conference | June 2025

Complex form behavior (cont’d)

• Perform calculations (e.g. scores)
• Launch context – patient, encounter, etc.
• Use CQL or FHIRPath for calculations
• Variables, initial expressions
• Create forms constructed from other forms

FHIR® SDC Conference | June 2025

Pre-population

• Current $populate Options:
• Observation based
• FHIRPath based
• StructureMap based

FHIR® SDC Conference | June 2025

Extraction

• Current $extract Options:
• Observation based
• Definition based
• Template based
• StructureMap based

FHIR® SDC Conference | June 2025

Adaptive forms

• Q:What is your name?
• A: Arthur
• Q: What is your quest?
• A: Holy Grail
• Q: What is the air-speed velocity of an unladen swallow?
• A:

54125-0

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86505-5

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86508-9

FHIR® SDC Conference | June 2025

Compositional forms

• How can designers encourage re-use with forms?
• Composition with sub-forms
• Create forms referencing only data elements
• $build to instantiate the full-blown Questionnaire

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FHIR® SDC Conference | June 2025

Exploring the SDC spec

• http://hl7.org/fhir/uv/sdc

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FHIR® SDC Conference | June 2025

lloyd@dogwoodhealthconsulting.com http://hl7.org/fhir/uv/sdc

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Or, better yet, include the community and ask/discuss on https://chat.fhir.org/#narrow/channel/179255-questionnaire

Got questions?

FHIR® SDC Conference | June 2025

Thank you!

FHIR® SDC Conference | June 2025