Clinical Trials: The Challenge of Patient Dropout and How to Prevent It

Globally, and in the U.S., the clinical trials market is growing rapidly. Clinical trials are vital for determining the safety and efficacy of medical interventions. Without them, researchers wouldn’t know for certain whether a prospective medicine, device, or procedure can produce the intended outcomes in target recipients. 

Patient turnover in clinical trials is an ongoing challenge. Participation is voluntary, so patients can drop out of a study whenever they want. Because the success of a trial relies so heavily on patient retention, a common concern among medical researchers is mitigating dropout rates.

Patient Dropout in Clinical Trials: Implications and Challenges

According to the National Center for Biotechnology Information, around 30% of participants ultimately drop out of trials, which can be costly and result in serious implications for research outcomes. 

Why do patients drop out of clinical trials?

Patients can drop out of a trial for any reason, but these three broad categories cover the main reasons.

  • Medical: Clinical trials commonly target people with a particular medical condition—patients who are hoping the intervention improves their health—so if the participants experience adverse effects, their disease progresses, or the treatment proves ineffective, they may see no reason to continue as trial subjects.
  • Logistic: Participation in a clinical trial is an act of devotion, requiring patients not only to commit time but also to undertake the burdens of travel and the rigors of the study. Over time, patients may feel inconvenienced by the efforts required by the trial or be unable to commit themselves consistently.
  • Psychosocial: Participants’ feelings toward a clinical trial may shift as it progresses. They may come to distrust the trial process and coordinators, grow dissatisfied with the experience, or lose motivation with successive visits to the trial site. 

What factors influence patient dropout in clinical trials?

The reasons for patient dropout stem from factors inherent to the trial and the participants themselves.

  • Trial design and protocol: Sometimes, how investigators plan and design a trial impacts patient retention. If the intervention or treatment regimen is too complex, for example, the enrolled patients may find it too challenging to be worthwhile. The length and intensity of a trial are key factors as well. The longer a trial runs and the more frequent the sessions are, the greater the likelihood of patient fatigue and dropout.
  • Problems at the trial site: Clear communication and active support from the staff are crucial for conveying a patient-centered approach. Without these, patients may fail to understand the protocol or purpose of the study, leading to poor engagement.
  • Patient attributes: The background and personal attributes of an enrolled patient can influence whether they stay in or drop out of a trial. Their socioeconomic status, for example, might inform whether it’s practical to attend trial sessions, while their individual expectations could affect their understanding of the trial process and the perceived benefits and risks of participation.

Consequences of Patient Turnover

High patient turnover can disrupt multiple facets of a clinical trial.

Impact on Trial Timelines

A clinical trial can’t progress without the appropriate number of participants, so dropouts can bottleneck the operation. Trial coordinators must recruit and screen potential replacements, select candidates, and acclimate them to the study protocol, which can delay a trial by months or even years.

Financial Implications

Time lost is also money lost, as recruiting a single patient can cost over $6,500, and replacing them can cost even more. Should a delay last long enough, the trial may require additional funding or run the risk of early termination.

Opportunity Cost

Opportunity cost is the loss of potential benefits resulting from choosing one alternative and not another. In the context of clinical trial participants, the opportunity cost applies to several areas:

  • Working with a lower number of participants or losing higher-quality participants may result in losses of data and poor data quality.
  • Lower retention can result in incomplete results and impaired interpretation of data. In a new-drug trial, for example, high dropout can lead to an incorrect assessment about the best dosage at phase 1, about drug efficacy at phase 2, and about the drug’s side effects at phase 3. For medical-device trials, you may see incomplete evaluations of device effectiveness, safety, performance, and usability.
  • In the event of early termination, society may lose out on the potential advances in medical care that the trial could have helped realize. A similar outcome could arise if incomplete data leads to challenges in obtaining regulatory approval or commercialization.

Strategies to Reduce Patient Dropouts

The key to reducing patient dropouts is to understand what motivates patients to continue participation. With that as your guiding principle, consider the following strategies for mitigating patient turnover in clinical trials:

  • A patient-centered trial design: Patient-centeredness means designing your trial around what appeals to participants and, if possible, involving them in the design process. Retention is more likely to improve if patients feel personally connected to the study.
  • Clear and transparent communication: Boosting patients’ understanding of a trial’s purpose and protocol is another way to help them feel connected to the study.
  • Use of remote monitoring and other technologies: Leverage tech to create a more convenient arrangement for your patients and reduce logistical barriers.
  • Financial incentives and reimbursements: Incentivizing patients with money may help them realize how their participation concretely benefits them

Partner with Medix for Clinical Research Staffing

At Medix, we have decades of experience helping staff life sciences organizations with temporary, temp-to-perm, and direct hire clinical research professionals, including coordinators, assistants, nurses, project managers, and directors. By partnering with us, you gain access to a new pool of highly-vetted, skilled clinical research talent, often experienced with patient drop-out prevention.

We have an intimate understanding of every step of the clinical trial lifecycle, understand the financial and medical ramifications of patient dropout, and can even assist with patient recruitment and retention efforts.

Poor patient retention is costly in terms of money, time, and outcomes, but you can overcome these challenges through protocol optimization, communication, incentives, and finding the right consulting and staffing partner, like Medix.


As a trusted partner in the life sciences space, Medix understands what it takes to keep a clinical trial on track. For further insight into how you can keep your trial participants engaged, get in touch with us today

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