Why Do Some Patients Enroll in Clinical Trials and Others Don’t?

Kristina Lopienski
February 14th, 2014

Without patients, clinical research doesn’t happen. Medical advances depend on their participation. Unfortunately, meeting enrollment goals remains a challenge despite the money and effort put into patient recruitment. While we have a clear understanding of the benefits of clinical trials, it can be difficult to put ourselves in the shoes of those who are unfamiliar with clinical research. To be fair, very few of us have ever been on the patient side. If we understand what keeps people away and what drives them to participate, we can implement more effective recruitment strategies.

Why don’t more people enroll in clinical trials?

Not everyone shares our excitement about clinical trials. In fact, the general public has doubts, misunderstandings, reservations, and concerns about participating in clinical research. Here are a few things preventing people from enrolling.

Lack of awareness

Low enrollment is attributed to many factors and varies on a per study basis, but if more people knew about clinical trials there would certainly be more participation – check out the infographic Lilly COI created about patient awareness in cancer trials. One study found that only one in three US adults knew about clinical trials, of the 1,000 surveyed.1 Perhaps this is because the people who have the most experience with clinical trials aren’t advocating for it. An online survey by CISCRP found that after a study concluded, 88% of participants said they rarely spoke about clinical research with others.3

Don’t think they qualify

Many people assume there aren’t any clinical trials that apply to their condition, or they doubt they’d be eligible to participate. Unless it’s brought to their direct attention as an option, some people may never consider enrolling. A Research!America poll found that 80% of 1,000 respondents claim a physician’s recommendation is an important factor in deciding to participate, yet only 22% of patients said a health care professional has talked to them about it.2


Many people are reluctant to participate because they are afraid. Unknown outcomes, uncertainty if a new treatment can help them, being experimented on, possible side effects, and receiving a placebo instead of an actual treatment are a few common fears. Although researchers cannot guarantee outcomes, patient safety is a top priority. Each trial has enforced oversight, and patients also have rights that help protect them.


Some people can’t commit to the time required to participate in a clinical trial. Others may find the available hours incompatible with their schedule. Travel is an issue for some, whether they’re unable to transport themselves or find a geographic location close enough. Other social and economic disadvantages contribute to some populations being underrepresented.

Confusion about insurance

Many patients want to make sure their insurance covers the study and pays for the care they receive. Health insurance plans differ, and not all costs and trials are always covered for enrolled patients. Those who are unsure about coverage should contact their insurance provider.

They intended to participate

Some people are more than willing but come to find they are unable to enroll or complete a trial for a variety of reasons. Early on some people will learn they’re not qualified for the study due to the strict inclusion/exclusion criteria. If a person is eligible but doesn’t sign and return the informed consent form, they cannot participate in the study. This document explains the scope of the study and makes the patient aware that their role is completely voluntary. Since patients have the right to drop out at any time, some discontinue before the study wraps up.

Why do patients participate in clinical trials?

On the flipside, there are several motivations of volunteers. Even though less than 10% of the American population participates in clinical trials,2 here are a few reasons why patients have enrolled.

They want to help advance medical knowledge

Clinical trials help answer questions in medicine, which leads to better ways to prevent, detect, diagnose, control, and treat illnesses. This can help future generations and others with the same disease. The opportunity to improve the health of others was an important factor in deciding to enroll for 86% of people.2

Access to promising treatments

When making treatment decisions, 89% of respondents said that the opportunity to possibly improve their own health is an important deciding factor to participate in a clinical trial.2 The idea of receiving the latest treatment before it’s widely available can be an exciting opportunity. In some cases there are no current treatments available, while others only participate if other options haven’t been able to help them.

Recommendation from someone they trust

The encouragement from physicians, pharmacists, family, friends, and others can influence the decision to participate. Word of mouth is often the starting point for awareness and consideration. When seeking information about clinical trials, 60% of people would go to their doctors.2

Receiving compensation

Some people enroll for clinical trials to make money, while compensation is just an added bonus for others. Not all studies pay participants, but 78% of people said that whether they would be paid is an important factor in the decision to participate in clinical trials.2

They had a good experience

Many participants become repeat patients after having positive experiences with clinical trials. Of the patients who have participated in a clinical trial, 95% said they would consider enrolling in another clinical research study.3

A patient who participates in clinical research not only receives a treatment that can potentially help them, but also generously helps those who will continue to be diagnosed in the future. After all, we have patients to thank for the treatments that are available in the market today. Clinical trials aren’t for everyone, but those who are curious can start the conversation to understand if it’s the right option for them. 


  1. CSR, Incorporated (2006). Evaluation of Patient Recruitment Strategies—Phase I Feasibility Study. http://aspe.hhs.gov/evaluation/fullreports/06/8384.pdf.
  2. Zogby Analytics for Research!America (2013). National Poll: Clinical Research. http://www.researchamerica.org/2013clinicaltrialspoll
  3. CISCRP (2013). 2013 Perceptions & Insights Study – Report on Study Participant Experiences. http://ciscrp.org/professional/reports/study-participant-experiences-2013-ciscrp-study.pdf


5 thoughts on “Why Do Some Patients Enroll in Clinical Trials and Others Don’t?

  1. Lack of awareness nd lack literacy about clinical trials and the betterment and importance of clinical trials in present generation

  2. Good points. The key to enrollment and retention is to take time to understand what the drivers and/or concerns are for each individual patient.

  3. Lack of awareness is really the overarching problem plaguing both the patient and industry sides of the equation. I agree with everything on the patient side. On the industry side, there needs to be more awareness of what drives interest: money, accessibility, safety. Advancing science is usually low on peoples’ why i do it list.

  4. My mother is thinking about participating in a research trial for aging women and I had no idea that there are so many benefits, so I am glad that I found this article. You make a great point that these trials are a great way to advance medical knowledge and help future generations. Also, the fact that there is typically compensation for the trial will make it a cost-effective endeavor for my mother. http://www.nhcr.com/

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