Published on 21/12/2025
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
- ✅ 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:
- Why was the pre-dose lab not performed? → Coordinator missed the lab schedule.
- Why was the schedule missed? → Visit checklist was not used.
- Why wasn’t it used? → Checklist not available in subject file.
- Why was it missing? → Coordinator believed it was optional.
- 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:
| Category | Example |
|---|---|
| Human Error | Forgetting to collect a lab sample despite SOP |
| Training Gap | Not knowing that a checklist was mandatory |
| Process Deficiency | No clear responsibility for visit preparation |
| Systemic Failure | Protocol design does not support real-world site workflow |
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.