Step-by-Step Guide to Conducting Structured Root Cause Analysis for Clinical Trial Deviations

Why Structured RCA Matters in Clinical Research

When deviations from protocol occur in a clinical trial, documenting the event isn’t enough. Regulatory bodies such as the FDA, EMA, and MHRA expect sponsors and investigators to conduct a structured Root Cause Analysis (RCA) that identifies the underlying causes—not just the symptoms—of non-compliance. This ensures effective CAPA (Corrective and Preventive Action) and prevents recurrence.

ICH-GCP E6(R2) reinforces the need for robust quality systems and risk-based thinking. A structured RCA supports both by ensuring that deviations are handled systematically and backed by documented, logical analysis. Poorly executed RCA—or none at all—is a common audit finding.

This guide walks you through a GCP-compliant, step-by-step RCA process applicable for sponsors, CROs, monitors, and sites.

Step 1: Define the Problem Clearly

Start with a precise, objective, and factual problem statement. Avoid assigning blame or assumptions.

Example: “Subject 103 missed pre-dose lab assessments on Visit 4 and received the investigational product without safety clearance.”

Include the deviation ID, study number, subject ID, date, protocol section violated, and any immediate impact on safety or data integrity.

Step 2: Assemble a Cross-Functional RCA Team

Include members from the following areas to ensure diverse perspectives:

• ✅ Site investigator or coordinator
• ✅ CRA or regional monitor
• ✅ Sponsor study manager or clinical lead
• ✅ QA representative
• ✅ Medical monitor (if applicable)

Assign an RCA facilitator who ensures impartial analysis and proper documentation.

Step 3: Gather Relevant Data and Timeline

Gather all documents and data sources associated with the deviation:

• ✅ Source documents and eCRFs
• ✅ Deviation form and initial classification
• ✅ Monitoring reports and correspondence
• ✅ SOPs and site training logs
• ✅ Audit trails (EDC, eTMF)

Create a timeline leading up to the deviation. This helps visualize any process or communication gaps that may have contributed.

Step 4: Identify Potential Causes Using an RCA Tool

Apply a structured RCA tool, such as:

• 5 Whys Analysis – Ideal for single-issue deviations
• Fishbone (Ishikawa) Diagram – Best for complex, multi-cause issues
• Process Mapping – Effective for workflow-related deviations

Example using 5 Whys:

1. Why was the pre-dose lab not performed? → Coordinator missed the lab schedule.
2. Why was the schedule missed? → Visit checklist was not used.
3. Why wasn’t it used? → Checklist not available in subject file.
4. Why was it missing? → Coordinator believed it was optional.
5. Why was it believed optional? → Training did not cover checklist use.

Root Cause: Training deficiency and unclear SOP on checklist use.

Step 5: Classify the Root Cause

Use a root cause category matrix to assign the issue to a broader failure domain:

Be cautious: labeling everything as “human error” can be a red flag in audits unless supported with evidence that no systemic factors were involved.

Step 6: Draft the RCA Report

The RCA report should include:

• ✅ Deviation summary and impact
• ✅ Participants involved in RCA
• ✅ Tools used (e.g., Fishbone, 5 Whys)
• ✅ Evidence collected and reviewed
• ✅ Root cause(s) identified
• ✅ Categorization of failure
• ✅ Recommendations for CAPA

Reports should be reviewed by the QA team and submitted into the trial’s quality documentation system (e.g., eTMF).

Step 7: Link RCA to Corrective and Preventive Actions

A structured RCA should directly feed into a tailored CAPA. For each root cause, ask:

• ✅ What action will correct the current issue?
• ✅ What change will prevent this from recurring?
• ✅ Who is responsible for implementation?
• ✅ What is the timeline?
• ✅ How will effectiveness be verified?

Example CAPA: Update SOP to include mandatory checklist review before each visit, retrain all site staff, and include checklist presence as a monitoring point in the CRA visit report template.

Step 8: Perform Effectiveness Check

RCA isn’t complete until the effectiveness of the CAPA is verified. This can be done by:

• ✅ Follow-up monitoring visits
• ✅ QA audits
• ✅ Spot checks during routine quality control reviews
• ✅ Deviation trend analysis

Tip: Include a timeline (e.g., 30 or 60 days post-CAPA) to trigger the effectiveness check, and document results accordingly.

Conclusion: Embed Structured RCA into Your Clinical Quality System

Structured RCA is not just a quality exercise—it is a regulatory expectation. Auditors frequently review RCA documentation for major protocol deviations and expect to see logical, data-supported reasoning behind all conclusions. By embedding RCA workflows into SOPs, training programs, and deviation logs, sponsors and CROs can drive true quality improvement while minimizing inspection risk.

Remember: a deviation without RCA is just a mistake waiting to happen again. A well-executed RCA transforms that mistake into a lesson—and a pathway to better compliance.