Experts call for action against fake health research participants

Fraudulent participants threaten the integrity of health research and therefore the policies and clinical decisions based on it, health experts warn.

Eileen Morrow and colleagues at the University of Oxford say the research community “must acknowledge the problem and devote resources to testing and implementing safeguards… to ensure that the data that underpins clinical care reflects the true voice of the patient.”

Fraudulent participants are people who provide misleading or inaccurate data to participate in health trials, or automated computer “bots” that mimic human behavior and responses.

The problem has become more acute in recent years as online recruitment has become central to modern health research and can impact all types of research, from surveys to randomized controlled trials.

The motivations of the fraudsters remain unknown, the authors explain. Although some reports suggest that monetary benefit is a motivating factor, not all research offers financial incentives, so other motives such as boredom, curiosity, or even an ideological desire to disrupt research may also play a role.

However, their influence is visible. A 2025 review found that 18 of 23 studies that looked for impostor participants in their datasets found them, with rates ranging from 3% to a maximum of 94%.

Researchers should routinely incorporate the detection and prevention of impostor participants into online research, given the potential impact on the study population, the authors write.

Common safeguards include identity verification procedures or CAPTCHA tests (asking participants to complete a task, such as reading and typing garbled letters).

They argue that research should at least transparently report what safeguards are used and acknowledge their limitations, and that journals should encourage consistent and transparent reporting of these safeguards.

Funders and institutions should also invest in infrastructure and training to help researchers keep pace with evolving tactics, while clinicians and policymakers should exercise caution when interpreting studies that use online recruitment if prevention of imposter participants is not mentioned.

They concluded: “Imposter participants are more than just a nuisance; they pose a systemic threat to health research. Their effects are visible and their detection inconsistent. At a time when online recruitment underpins everything from randomized controlled trials to surveys, they risk undermining the integrity of health research and the decisions based on it.”