Glossary · Data and documentsUpdated September 28, 2026

What is a case report form (CRF)?

A case report form is the document, printed or electronic, in which a clinical trial records all the data the protocol requires for each participant. An electronic version is called an eCRF.

  • CRF in plain language
  • How it works in practice
  • Related terms

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Data collectionCRF / eCRF

Case report form

noun · clinical research

A printed or electronic document designed to record all protocol-required information to be reported to the sponsor for each trial participant.

Related terms

Source documenteCRFCDASHAnnotated CRFEdit check

In short

  • The CRF is where trial data is recorded for the sponsor. Each participant has a set of CRFs, often called a casebook.
  • It is not the source document. Source is where data is first recorded (clinic notes, lab reports); the CRF transcribes or captures what the protocol needs from it, unless data is entered directly as source.
  • Most trials now use eCRFs in an EDC system, which add skip logic, edit checks, calculated fields and an audit trail of every change.
  • An annotated CRF maps each field to its dataset variable for regulatory submissions; a blank CRF is often submitted to ethics committees.

Explained

What goes on a CRF

A CRF contains exactly what the protocol says must be collected: demographics and eligibility at screening, assessments at each visit, and logs of events that happen on their own timeline, such as adverse events and concomitant medications. Anything not required by the protocol or the analysis plan generally does not belong on it.

CRFs are organised into forms. Visit forms hold data collected at scheduled visits, such as vital signs or questionnaires. Log forms hold repeating records, such as adverse events, with one row per event. Standard forms usually follow CDISC CDASH conventions so that data maps cleanly to SDTM datasets later. See how to design an eCRF for design rules, and the eCRF templates for worked examples such as the adverse event form.

CRF versus source document

Source documents are the original records of clinical findings: hospital notes, lab printouts, ECG tracings, participant diaries. The CRF records the protocol-required subset for the sponsor. Monitors check CRF data against source through source data verification. When data is entered directly into an eCRF with no earlier record (for example ePRO answers), the eCRF entry itself is the source.

Blank and annotated CRFs

A blank CRF (every form, printed empty) shows ethics committees and auditors what will be collected. An annotated CRF labels each field with its dataset variable name and is part of the documentation submitted with study data to regulators.

Blank eCRF · no subject data

Visit by form matrix

FormSCRD1W2W4W8EOS
DemographicsX
Vital signsXXXXXX
LaboratoryXXX
ECGXX

3. Was the ECG performed?

☐ Yes☐ No

If No, complete question 4.

Protocol CAP-001 · v1.0Page 3 of 24

In Capture

eCRFs with the checks built in

Capture builds eCRFs without code, with ten question types plus table sections, skip logic, edit checks that raise auto-queries and fourteen built-in calculators. Forms move from draft to approved, and only approved forms reach the casebook. The blank eCRF PDF (cover page, form index, visit-by-form matrix and every approved form) exports in one click, and data exports include an annotated CRF and data dictionary.

  • AI drafts questions and lab tables from a description or file.
  • Field-level audit trail on every entry.
  • Blank eCRF and annotated CRF exports.
CRF builder for clinical trials

Stage 1

Draft

Build and edit freely

Stage 2

Approved

Locked for live use

Stage 3

In the casebook

Only approved forms

Audit trail
  • SDV requirement changed on Systolic BP

    Data manager · Reason: critical safety value

  • Form approved: Vital Signs (VS) v2

    Study owner · Locked for live use

  • Answer changed: Weight 68.0 to 68.5 kg

    Site coordinator · Reason: transcription error

FAQ

Common questions

Something not covered here? Ask us directly.

What does CRF stand for?

Case report form. An electronic case report form is an eCRF.

Is a CRF a source document?

Usually not. Source documents are the original records; the CRF records the protocol-required data for the sponsor. Direct electronic entry can make the eCRF the source for that data.

Who completes the CRF?

Site staff such as research coordinators and investigators, and participants themselves for ePRO forms.

What is an annotated CRF?

A CRF labelled with the dataset variable for each field, used to document how collected data maps to submission datasets.

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