Glossary · Monitoring and qualityUpdated September 28, 2026

What is source data verification (SDV)?

Source data verification is the process of comparing data recorded in the case report form with the original source documents to confirm it is accurate and complete.

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

Free sandbox · No credit card · 21 CFR Part 11 aligned

Vital signs · SDV configuration
SDV: 3 of 5 fieldsSDV config v3
  • Date of birth
  • Systolic blood pressure
  • Diastolic blood pressure
  • BMI (calculated)never verified
  • Position during measurement
  • Comments

Changed by Data manager · reason: critical safety value added

In short

  • SDV checks transcription: does the eCRF value match the source record?
  • It differs from source data review (SDR), which reviews source documents for protocol compliance and quality, not just matching values.
  • 100% SDV checks every field. Targeted or risk-based SDV focuses on critical data, such as eligibility, primary endpoints and safety.
  • Regulators and industry have moved towards targeted SDV, because exhaustive checking corrects little that matters and consumes large amounts of monitoring time.

Explained

Why SDV moved from everything to what matters

For many years monitors verified every data point against source at every site visit. Analyses of monitoring practices found that this exhaustive approach changed very little data, and that most of the errors it caught had no effect on the study's conclusions. At the same time, it was one of the largest costs in running a trial.

Modern guidance, including FDA's guidance on risk-based monitoring and ICH E6, encourages sponsors to identify the data and processes critical to participant safety and result reliability and focus verification there. Remaining data is covered by centralised review, edit checks and targeted SDV based on risk. See risk-based monitoring.

Remote SDV

When sites can give monitors secure remote access to source records, SDV can happen without travel. It depends on local rules about access to medical records and on the site's systems. Remote SDV and on-site visits are often combined.

In Capture

SDV set per field, and changeable without a new form version

Tick the fields that need verification on each form. Only fields in the critical set show an SDV marker; monitors verify field by field or all at once and submit. The SDV set can change after approval, creating a new SDV configuration version with a reason, and calculated fields are excluded automatically.

  • "SDV: x of y fields" per form.
  • Past verifications kept in history.
  • Queries raised in context from the field.
Risk-based monitoring and SDV software
Vital signs · SDV configuration
SDV: 3 of 5 fieldsSDV config v3
  • Date of birth
  • Systolic blood pressure
  • Diastolic blood pressure
  • BMI (calculated)never verified
  • Position during measurement
  • Comments

Changed by Data manager · reason: critical safety value added

FAQ

Common questions

Something not covered here? Ask us directly.

What does SDV stand for?

Source data verification.

What is the difference between SDV and SDR?

SDV checks that CRF data matches source. SDR reviews source documents more broadly for protocol compliance, quality and issues that may not be in the CRF.

Is 100% SDV required?

No. Regulators accept risk-based approaches that focus verification on critical data, supported by centralised monitoring.

Which fields should be verified?

Typically consent, eligibility, primary and key secondary endpoints, dosing and safety data, based on your risk assessment.

Verify the fields that matter

Per-field SDV configuration in a free sandbox.

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