How to Maintain Data Integrity in Clinical Research: A Step-by-Step Guide for Site Staff

In clinical research, data must be accurate, reliable, and complete. This is called data integrity. Without it, the entire study can be questioned or rejected.

This guide helps site staff follow the right steps to protect data every day. It explains how to record, check, and store data properly, so that every entry can be trusted.

What Is Data Integrity?

Data integrity means the data is:

• Accurate: No mistakes
  
• Complete: Nothing missing
  
• Consistent: Matches across all records
  
• Original: Taken from real observations or devices
  
• Reliable: Can be traced and verified later
  

Step 1: Use ALCOA+ Principles

The best way to remember what makes good data is ALCOA+. It stands for:

• Attributable – You must know who recorded the data.
  
• Legible – It must be clear and readable.
  
• Contemporaneous – Record data at the time it happens.
  
• Original – Keep the first record, not a copy.
  
• Accurate – It must reflect what really happened.
  
• + means it must also be: 
  • Complete
    
  • Consistent
    
  • Enduring
    
  • Available
    

Step 2: Daily Practices for Secure Data Entry

Every staff member must follow simple habits during data entry.

Use Approved Tools Only

• Use the sponsor’s electronic data capture (EDC) system or paper forms they approve.
  
• Don’t use personal notebooks, sticky notes, or unapproved spreadsheets.
  

Record Immediately

• Enter data as soon as possible after seeing a patient or checking a result.
  
• Don’t try to remember and enter it later, this increases mistakes.
  

No White-Out or Erasers

• If there’s an error, draw a line through it, add initials, date, and correct data.
  
• Keep the old entry visible.
  

Step 3: Verification Before Submission

Check data before sending it to the monitor or sponsor.

Source Data Verification (SDV)

• Compare what’s in the EDC system to the source documents (like lab reports, patient charts).
  
• Make sure numbers match, especially for: 
  • Vital signs
    
  • Lab results
    
  • Visit dates
    
  • Medication details
    

Double-Check Key Fields

• Mistakes in fields like patient ID, adverse events, or doses can lead to protocol violations.
  
• Always have a second person review critical entries, if possible.
  

Step 4: Build an Audit Trail

An audit trail shows who entered or changed what, when, and why.

Electronic Records

• Most EDC systems have built-in audit trails.
  
• Don’t try to delete or hide past entries.
  

Paper Records

• Write all changes clearly with the reason for the update.
  
• Use initials and date for each correction.
  
• Don’t use pencils, always write in ink.
  

Step 5: Good Documentation Habits

Follow SOPs

• Stick to your site’s Standard Operating Procedures (SOPs) for how data is collected and handled.
  
• Use the correct version of forms and protocols.
  

Label Everything

• All notes and forms should include: 
  • Patient initials or ID
    
  • Study number
    
  • Date and time
    
  • Staff member’s initials or signature
    

Keep Documents Organized

• Store all documents in locked cabinets or password-protected folders, depending on format.
  
• Use a document checklist to track what is filed and where.
  

Step 6: Secure Data Storage

Data must be stored in a way that protects it from loss or changes.

Paper Records

• Keep in locked rooms or cabinets.
  
• No food, drink, or personal items near data.
  
• Control access, only authorized staff should enter.
  

Electronic Data

• Use strong passwords and change them regularly.
  
• Log out when stepping away from the computer.
  
• Back up data according to your site’s IT policy.
  

Step 7: Protect Patient Confidentiality

• Do not write patient names on forms unless required.
  
• Use coded IDs and store the ID key separately.
  
• Never email personal health information unless it’s encrypted and allowed by the sponsor.
  

Step 8: Prepare for Monitoring Visits

Monitors check data for accuracy. You can make their job easier and help your site by:

• Having source documents ready
  
• Keeping logs up to date (screening logs, delegation logs, etc.)
  
• Explaining any changes clearly in notes
  

Monitors may also look at trends, for example, if every patient reports the exact same side effects or if lab results seem “too perfect,” they may question data reliability.

Step 9: Stay Ready for Inspections

Inspectors from FDA or other agencies may visit. They will look at:

• How data was collected
  
• Who entered it
  
• How it was corrected
  
• How records are stored
  

Be honest and cooperative. Never hide errors, explain them clearly and show how they were corrected.

Step 10: Ongoing Training and Feedback

Clinical trials often last months or years. Staff turnover can lead to mistakes. Keep everyone on the same page by:

• Giving regular refreshers on data entry rules
  
• Holding brief team meetings to review common errors
  
• Updating training logs after each session
  

Common Mistakes to Avoid

Final Thoughts

Strong data integrity isn’t just about filling out forms. It’s about building trust, between the site, the sponsor, the regulators, and the public. Every small step, like writing neatly or checking a number twice, adds up to reliable, valuable research.