Q. What is a duplicate or professional research subject and how do they affect clinical trials?
A. A duplicate research subject is an individual who attempts to enroll in more than one clinical trial concurrently or within a short time frame—often without disclosing recent participation. A professional research subject participates in multiple studies primarily for financial compensation, frequently concealing prior trial involvement, medical history, or concurrent participation.
These individuals can significantly jeopardize a clinical trial’s validity by introducing confounding variables, non-compliance, and inaccurate data. Their participation can undermine study outcomes, increase placebo response, and dilute statistical power, ultimately risking regulatory approval.
Q. How would a duplicate or professional subject affect safety or data integrity in a clinical trial?
A. Duplicate or professional subjects pose serious safety and data integrity risks.
- Safety: If a subject enrolls in multiple trials simultaneously or too closely together, they may be exposed to interacting investigational drugs, increasing the risk of adverse events. These events may be misattributed to your product, skewing safety data.
- Data Integrity: These subjects may provide biased or fabricated responses, fail to meet eligibility criteria, or fail to adhere to protocol timelines, which can compromise the reliability and reproducibility of trial results.
Q. What is the incidence of duplicate research subjects in clinical trials?
A. The incidence of duplicate or professional research subjects is much higher than most sponsors and sites realize—and often severely underestimated. Real-world data show that up to 10% or more of enrolled subjects in certain studies may be duplicates.
While high-risk areas such as CNS, pain, psychiatry, metabolic disorders (e.g., obesity/GLP-1), and vaccines are well documented, other therapeutic areas—including dermatology, ophthalmology, respiratory, gastroenterology, and many others—are also at risk. No study or geography is immune.
These issues often go undetected without a purpose-built, cross-sponsor solution. Verified Clinical Trials (VCT) is the only global system capable of detecting and preventing duplicate and professional subjects at the time of screening—before dosing or enrollment. Unlike manual checks or limited in-house tools, VCT proactively protects subject safety and data integrity, safeguarding trials from failure and regulatory risk.
Q. Are duplicate or professional subjects siloed to a particular therapeutic area or geography?
A. No. This issue affects all therapeutic areas and is not confined to any specific geography. While certain areas—such as CNS, pain, obesity, and vaccines—may see higher rates due to subject motivation or trial density, any study, anywhere in the world, is at risk. Verified Clinical Trials has seen cross-therapeutic, cross-border duplication that underscores the global and widespread nature of this issue.
Q. When is the best time to detect and prevent duplicate research subjects?
A. The best—and only truly effective—time to detect and prevent duplicate subjects is at the time of screening, before the subject is enrolled or dosed. Prevention at this early stage protects the trial from downstream safety risks, protocol violations, and costly data clean-up or trial failure.
Q. Do duplicate research subjects only occur in phase I clinical trials or are they present in global, multi-site trials as well?
A. Duplicate subjects are present across all phases of clinical research and in global, multi-site trials. While Phase I trials may be more susceptible due to healthy volunteer participation and financial incentives, Verified Clinical Trials has identified duplicate activity across Phases II, III, and IV, including observational and registry studies worldwide.
Q. What is the leading cross-sponsor, cross-therapeutic area solution to detect and prevent duplicate and professional research subjects?
A. Verified Clinical Trials (VCT) is the only global solution that provides real-time, cross-sponsor, and cross-therapeutic area verification of research participants at the time of screening. VCT’s secure, privacy-compliant database protects against duplicate enrollment and professional subjects across more than 40 countries. With robust biometric options and widespread adoption by major pharmaceutical companies, CROs, and research sites, VCT is the industry standard for safeguarding clinical trial integrity and subject safety.
This behavior introduces significant risks, as professional patients in clinical trials are often duplicate subjects in clinical trials, enrolling more than once or participating in several studies simultaneously.
The Risks of Professional Patients and Duplicate Subjects in Clinical Trials
The presence of professional patients in clinical trials and duplicate subjects in clinical trials can severely impact the outcome and reliability of research studies:
- Data Integrity Issues: Professional patients frequently misrepresent their medical history and participation status, leading to unreliable and invalid data that compromises clinical trial results.
- Increased Placebo Response Rates: Professional patients in clinical trials often artificially inflate placebo responses, making it difficult to accurately measure the true efficacy of investigational products.
- Clinical Trial Failure: Trials involving professional patients and duplicate subjects in clinical trials are at higher risk of failing to meet endpoints, leading to costly delays, repeat studies, or the abandonment of promising therapies.
- Patient Safety Concerns: Enrolling in multiple trials exposes professional patients to overlapping investigational treatments, significantly increasing the risk of adverse events, drug interactions, and other serious health consequences.
Verified Clinical Trials: The Solution for Professional Patients and Duplicate Subjects
Verified Clinical Trials (VCT) provides the global research community with the most effective protection against professional patients in clinical trials and duplicate subjects in clinical trials. VCT is the only solution that offers real-time detection and prevention at the time of screening, verifying a subject’s clinical trial participation history across sponsors and therapeutic areas.
Our comprehensive protection continues throughout the entire duration of the study, offering unparalleled safeguards for data quality and subject safety.
With Verified Clinical Trials, you can:
- Detect professional patients in clinical trials before enrollment
- Prevent duplicate subjects in clinical trials at the time of screening
- Protect the integrity of your data by ensuring genuine, compliant participation
- Safeguard subject safety by preventing simultaneous participation in multiple trials
- Reduce the risk of trial failure, costly delays, and regulatory scrutiny
Trusted by Leading Pharmaceutical Companies and Clinical Trial Sponsors
For more than a decade, Verified Clinical Trials has been the trusted partner for the world’s leading pharmaceutical companies, clinical trial sponsors, and contract research organizations. Our unmatched cross-sponsor and cross-therapeutic area protections have made VCT the industry gold standard for detecting and preventing professional patients and duplicate subjects in clinical trials.
There is no other solution like Verified Clinical Trials. Only VCT offers a global research subject registry capable of truly protecting your study from the threats posed by professional patients and duplicate subjects in clinical trials.
At Verified Clinical Trials, we are dedicated to safeguarding subject safety, preserving data integrity, and ensuring clinical trial success.
