A Complete Guide to GCP-Compliant Clinical Documentation
In clinical trials, documentation is everything. No matter how well a study is executed, “If it isn’t documented, it didn’t happen.”
The Source Documents and Subject Files are the foundation of data integrity and regulatory compliance. For every Clinical Research Coordinator (CRC), maintaining them accurately and consistently is a core responsibility.
This article explains what source documents and subject files are, why they are important, and the best practices CRCs must follow to maintain them properly as per ICH-GCP guidelines, Schedule Y, and Good Documentation Practices (GDP).

What Are Source Documents?
Source Documents are the original records that contain all the clinical, laboratory, and administrative data collected during a trial.
They serve as the first place where data are recorded before being transcribed into the Case Report Form (CRF/eCRF).
Examples of Source Documents:
Subject medical records or hospital charts
Laboratory reports, imaging results, ECG printouts
Informed consent forms (signed and dated)
Visit notes, progress notes, and vitals record sheets
Drug dispensing and return logs
Subject diaries or questionnaires
AE/SAE reports and follow-up documents
Source documents prove the authenticity and accuracy of the data reported to the sponsor and regulatory agencies.
What Is a Subject File?
The Subject File (or Subject Binder) is a compilation of all documents related to a single trial participant.
It provides a chronological record of the subject’s participation from screening to the end of study, ensuring that every procedure, consent, visit, and event is traceable.
Typical Subject File Contents:
Subject identification code list (kept confidential)
Signed informed consent form (ICF)
Screening and enrollment logs
Eligibility checklist
Visit-wise source notes
Vital signs, lab reports, ECGs
IP dispensing and accountability records
AE/SAE reports and narratives
Withdrawal or completion form
Each subject’s file acts as legal evidence of their participation and the site’s adherence to the protocol.
Importance of Proper Maintenance
Accurate and well-organized documentation helps ensure:
Data Integrity: Proof that data is reliable, traceable, and verifiable.
Regulatory Compliance: Meets ICH-GCP, Schedule Y, and local EC requirements.
Audit Readiness: Allows quick access for CRAs, sponsors, or regulatory inspectors.
Patient Safety: Tracks all procedures, medications, and adverse events.
Transparency: Demonstrates that the site followed protocol and SOPs diligently.
Best Practices for Maintaining Source Documents & Subject Files
1. Ensure Legibility and Accuracy
All entries must be clear, readable, dated, and signed by the person making them.
Avoid overwriting or using correction fluid.
For any correction, draw a single line, write the correction nearby, and initial/date it.
Use blue or black ink only (no pencil).
💡 Tip: Always follow ALCOA+ principles — Attributable, Legible, Contemporaneous, Original, Accurate, Complete, Consistent, Enduring, Available.
2. Record Data in Real-Time
Enter data immediately at the time of observation — don’t rely on memory.
Late entries should be marked as “late entry” with a justification.
Timely recording ensures accuracy and meets the “contemporaneous” GCP requirement.
3. Maintain Proper Source Document Templates
Use pre-approved source note templates provided by the sponsor or site SOP.
Templates should include fields for:
Subject ID, Visit Number, Date/Time
Vitals, Procedures, IP dispensing
Adverse Events, PI/CRC signatures
✅ Example: “Visit 2 – Day 14: Vitals checked, IP dispensed, AE assessed – signed by CRC & verified by PI.”
4. Reconcile Source Data with CRF/eCRF
Regularly verify that CRF/eCRF entries match the corresponding source records.
Address discrepancies promptly using Data Clarification Forms (DCFs).
Never modify source data to fit CRF values — always correct based on verified evidence.
5. Maintain Confidentiality and Security
Subject identifiers (name, contact details) must never appear in CRFs or sponsor communications.
Keep files in locked cabinets or restricted-access digital systems.
Use only subject ID codes in CRFs and tracking documents.
Protect against loss, theft, or unauthorized viewing.
6. Assign Clear Responsibilities
PI: Overall responsibility for accuracy and integrity.
CRC: Day-to-day maintenance, entry, and organization of source data.
CRA: Verifies consistency and completeness during monitoring visits.
Ensure all delegated responsibilities are documented in the Delegation of Duties Log.
7. File Documents in Chronological Order
Arrange each subject’s file in chronological sequence (Visit 1 → Visit 2 → …).
Separate each visit with colored dividers or labels.
Maintain a Subject File Index for quick document retrieval.
8. Implement Version Control and Updates
If templates or forms are revised, label the version number clearly.
Retain older versions marked “Superseded.”
Maintain a Version Control Log for easy tracking during audits.
9. Include All Supporting Records
Attach lab reports, ECGs, X-rays, and any external test results.
Mark them with Subject ID, Date, and Visit Number.
Ensure reports are reviewed and signed by the Investigator before filing.
10. Regular Review and Quality Check
CRCs should conduct weekly internal reviews to confirm file completeness.
The CRA should perform document verification during monitoring visits.
Any missing pages, unsigned entries, or unfiled documents must be logged and resolved.
Storage and Retention
During Study: Keep subject files in a secured, restricted-access cabinet or room.
After Study Completion: Archive files for the sponsor-specified period (usually 15–25 years).
Maintain archive logs and ensure easy retrieval during inspections.
Avoid exposure to moisture, sunlight, or temperature fluctuations.
Common Mistakes CRCs Should Avoid
❌ Missing PI or CRC signatures on source pages
❌ Illegible handwriting or missing dates
❌ Using sticky notes or loose papers as source data
❌ Mixing multiple subjects’ data in one file
❌ Not updating logs or visit sheets in real-time
❌ Poor reconciliation between source and eCRF
💡 Tips for CRCs to Stay Audit-Ready
Perform monthly file self-audits.
Keep updated training records and SOP acknowledgment sheets.
Use document tracking logs for filing consistency.
During monitoring visits, ensure files are neatly labeled and accessible.
Always have the latest versions of informed consent forms and protocols in the ISF.
Final Thoughts
Maintaining source documents and subject files properly is not just a regulatory requirement — it’s a reflection of the quality culture of your research site.
A well-maintained documentation system ensures patient safety, data reliability, and smooth audits. For CRCs, mastering these best practices builds confidence with sponsors, CRAs, and inspectors — paving the way for professional growth in Clinical Operations.
📌 Remember: Every signature, every note, every date tells the story of the trial — keep it clean, consistent, and compliant.
