18.2 Monitoring Methods and Source Review

Monitoring Methods and Source Review

On-site monitoring can be important within a justified risk-proportionate strategy; E6(R3) does not require the same on-site approach for every trial. Rather than spending 100% of on-site time seated behind closed doors reviewing paper charts, the CRA focuses on physical inspections, investigator oversight evaluations, and observational verification:

• Physical Facility & Pharmacy Inspection: Auditing investigational product storage facilities, verifying continuous temperature logger calibration, inspecting biological sample freezers (-80°C), and observing drug reconstitution procedures.
• Observational Verification: Observing study staff conduct clinical assessments, verifying that specialized diagnostic equipment (e.g., calibrated spirometers or retinal scanners) is operated properly.
• Investigator Engagement: Conducting in-depth face-to-face debriefs with the Principal Investigator to assess protocol comprehension, clinical decision-making, and supervisory oversight.
• Targeted SDV & In-Depth Source Data Review (SDR).

Remote Monitoring

Remote monitoring involves off-site activities conducted by field CRAs, focusing on individual site data and documentation with a focus on that site; roles and analytical responsibilities can overlap:

• Reviewing electronic trial master file (eTMF) and investigator site file (ISF) regulatory submissions.
• Reviewing electronic Case Report Form (eCRF) completion timeliness and issuing data queries.
• Inspecting direct electronic health record (EHR) records remotely where institutional security policies and participant consent permit secure off-site access.

Modality Comparison Matrix

Source Data Verification (SDV) vs. Source Data Review (SDR)

A useful CCRA distinction is the distinction between Source Data Verification (SDV) and Source Data Review (SDR). These terms are not interchangeable.

Documenting a monitoring plan

A plan should explain the chosen strategy, responsibilities, activities, methods, rationale, timing, escalation and how follow-up is documented. Define which data/processes receive review and how the intensity may change as evidence accumulates. Critical consent, eligibility, safety, dosing and endpoint processes deserve particular attention, but ICH does not prescribe one universal 100% SDV list or first-three-participants rule.

For an illustrative trial, a sponsor might verify every primary endpoint and sample lower-risk transcribed fields. Another justified strategy may use different coverage supported by electronic controls and central review. The site still must obtain consent and follow every applicable protocol requirement for every participant. Risk-based monitoring changes assurance methods, not the underlying participant protections.

A risk trigger should lead to a proportionate investigation, not an automatic accusation. Missing records, low AE rates or unusual digits can reflect late entry, rounding, different participant populations, system configuration or misconduct. Check the denominator, exposure period and data completeness; obtain source evidence; document the explanation; and escalate unresolved concerns through the plan.

Key Risk Indicators (KRIs): Metrics, Operational Thresholds & Red Flags

Key Risk Indicators (KRIs) are predefined operational, safety, and data quality metrics evaluated dynamically during trial conduct to monitor risk levels at individual investigative sites. When a site's metric crosses a predefined mathematical threshold (defined in the trial plan with appropriate denominators and context), an automated alert is triggered, prompting immediate investigation.

Critical KRIs and Clinical Red Flags

1. Screening-to-Enrollment Ratio Outliers:

   • Metric: Number of participants enrolled divided by number screened.
   • Operational Red Flag: Across a global oncology trial, the average screening-to-enrollment ratio is 35% due to stringent biomarker exclusion criteria. Site 104 screens 15 subjects and successfully randomizes all 15 (100% conversion rate).
   • CRA Operational Interpretation: A 100% enrollment rate in a restrictive trial requires investigation in context. It may indicate that site staff may be enrolling ineligible subjects, misinterpreting exclusion criteria, or manipulating screening laboratory results. The responsible monitoring team should assess the signal and arrange proportionate follow-up, potentially including targeted source review or an on-site visit. A signal alone does not prove misconduct or require a formal audit.

2. Consent-to-Randomization Timing Discrepancies:

   • Metric: Time elapsed between documented informed consent signature and formal randomization in the IRT system.
   • Operational Red Flag: Subject 202 is randomized at 09:15 AM, while the signed informed consent form timestamp in the source notes is recorded as 11:30 AM on the same day.
   • CRA Operational Interpretation: Randomizing a participant or performing study assessments prior to obtaining signed informed consent conflicts with the applicable informed-consent process in E6(R3). Centralized audit trail analytics detect these timing anomalies automatically.

Official sources

Checked October 18, 2026: ICH E6(R3), Principles and Annex 1, ICH E8(R1).