Top Barriers to Participation in Clinical Trials

April Schultz
October 12th, 2017

Recruiting study participants is one of the most challenging tasks in the clinical trial process, and arguably one of the biggest barriers to success in clinical research. During Forte’s 2017 national survey of over 900 clinical research professionals, recruiting enough participants to trial was identified as one of the top three pain points in clinical trial conduct.

Low enrollment is a chronic problem for many studies. According to an Applied Clinical Trial Stakeholder Survey in 2011, 19% of registered trials that closed or terminated either failed to meet accrual goals (85% of expected enrollment) or were terminated early due to insufficient accrual. 

So, why is patient recruitment such a significant and ongoing challenge for research organizations? Understanding the various factors that influence an individuals decision to participate in a study can often help research professionals determine the root cause for enrollment problems. In this infographic, we explore the common barriers individuals face when deciding whether or not to participate in a clinical trial.

Top Barriers to Patient Participation Infographic

Misconceptions and a lack of awareness seem to be the most significant barriers for individuals who otherwise might be willing to participate in a clinical trial. It’s critical to address these barriers by spreading positive, community-forward information about clinical research and encouraging more industry stakeholders to participate in outreach efforts.

Text Version

Why are Under-Enrolling Clinical Trials a Significant Problem?

The consequences of low accrual in clinical trials is significant on a number of levels, for all stakeholders – sites, sponsors and patients. Some consequences include:

  • Ethical implications
  • Relinquish scientific validity
  • Missed opportunities for patients
  • Wasted time, resources and funds

Of the registered trials in 2011, 19% of closed or terminated trials either failed to meet accrual goals or were terminated early due to insufficient accrual.

2016 Study of Forte Benchmarks Data

Of 9,000 recorded trials, 23% were terminated or closed. On average, 120 hours were spent on trials that were ultimately terminated due to insufficient accrual. This equals roughly three full-time employees-worth of wasted time per center.

Does Public Perception of Clinical Research Play a Role in this Issue?

As found in a 2015 CISCRP global study of over 12,000 individuals, the public perception of clinical research is relatively positive. The majority of individuals surveyed indicated they agree or somewhat agree that participation in clinical research:

  • is important to the discovery and development of new medicines
  • allows them to contribute to the advancement of science
  • would help them learn more about their medical condition

In total, 79% of individuals believe clinical research is either somewhat or very safe. Meanwhile, 57% of individuals are very or somewhat willing to participate in a clinical research study.

Barriers to Patient Participation

Lack of Awareness

The most trusted information sources for clinical research studies:

  • Clinical research information provided on the online clinical trial registry maintained by the government
  • Posters or pamphlets found in a doctor’s office or clinic
  • Online patient communities or social media sites

83% of surveyed individuals said a doctor recommendation would likely influence their participation decision. 58% rarely, if ever, consider discussing clinical research options with their doctor. 85% of surveyed individuals are generally comfortable presenting any clinical research information they find to their doctor. Only 17% have actually presented clinical research information to their doctor.


43% of those who are not willing to participate in a clinical research study mentioned they are not willing to take a chance with their health. Additionally, 41% mentioned they are concerned about the risks associated with clinical research. Other top reasons mentioned for not willing to participate include not knowing enough about clinical research (21%), and not wanting to risk receiving the placebo (19%).


In 2015, 35% of surveyed individuals agree that research participants are gambling with their health compared to only 29% in 2013. 27% of surveyed individuals report being ‘not very/not at all confident’ that he or she would find an appropriate research study.


Important information prior to participation decision:

  • 55% said physical location of the research center
  • 53% said the number of study visits and types of medical procedures required
  • 49% said time commitment
  • 22% of respondents were not told why they did not qualify for a study

For study follow up, 52% said whether or not they would receive a summary of the study results after participation ended was very important information prior to their decision to participate. 



Want to know more?

Learn more ways to encourage participation in clinical trials, build a successful advertising campaign and increase your clinical trial accrual in our free eBook, “Patient Recruitment in Clinical Trials: Steps to Develop a Successful Enrollment Strategy.