Participation burden: what a clinical trial really asks of patients
What does it really take to participate in a clinical trial? Beyond signing a consent form, participants face a series of demands: frequent visits, medical procedures, daily diaries, travel to the study site, and time away from work and family. This is called participation burden, and it is one of the main reasons why up to 30 percent of enrolled participants drop out before a trial is complete. Understanding and reducing that burden is essential to running research that finishes on time and produces trustworthy results.
The different forms of burden
Participation burden shows up in several ways. Time burden covers the hours spent at study visits, traveling, and completing diary entries. Physical burden comes from invasive procedures like blood draws, biopsies, and imaging scans. Psychological burden includes anxiety about an experimental treatment, uncertainty about randomization, and worry about side effects. Financial burden means lost wages, travel costs, childcare, and time off work. Logistical burden is the everyday friction of scheduling visits around work and family, arranging transportation, and managing complex medication schedules. Most participants feel several of these at once.
Visits are often the heaviest part
Visit burden is usually the worst. A typical phase three trial may require monthly visits for six months, then quarterly visits for another year. Each visit can take two to four hours including travel, waiting, procedures, and consultations. For patients who live far from the study site, and many travel over an hour each way, a single visit can consume an entire day. Multiply that by dozens of visits over months or years, and the cumulative time commitment becomes enormous.
Procedures add another layer. Blood draws at every visit, sometimes multiple vials for different tests. Imaging scans such as CT, MRI, or PET that require preparation, exposure to radiation, and extended time in the machine. Biopsies that can be painful and require recovery time. Questionnaires that take 30 to 60 minutes to complete. Each procedure alone is manageable. Together they create a significant physical and time burden.
Many trials also require daily diaries, recording symptoms, medication use, side effects, and quality of life measures. These diaries are essential for collecting patient-reported outcomes, but they impose a daily time commitment that can feel overwhelming. Participants may forget to complete entries, leading to missing data. Electronic diaries on smartphones or tablets have improved compliance, but the burden remains. Some trials now use passive data collection from wearable devices to reduce it.
Who feels the strain
The burden looks different from different perspectives. From the patient's side, each visit means taking time off work, arranging childcare, finding transportation, and fitting the trial into an already busy life. From the site's side, each visit requires staff time, clinic resources, and data entry. Both sides feel the pressure, but the consequences differ. Patients may drop out. Sites may struggle with recruitment and retention targets that affect the whole trial.
The money question also splits unevenly. Patients bear the direct costs: travel, parking, meals, lost wages, and childcare. Sponsors cover the experimental treatment and trial-related tests, but often do not reimburse all out-of-pocket expenses. Sites carry operational costs like staff salaries, equipment, and facility overhead. When the financial burden on patients gets too high, they decline to participate or drop out early. Studies consistently show that travel distance and lost wages are among the strongest predictors of dropout (ClinicalTrials.gov on why people participate).
What good participation looks like
Participation itself is a commitment, and regulators and sponsors have spent years defining what fair, informed participation means. The FDA describes clinical trials as the final stage of a long drug development process that depends on volunteers who are fully informed about risks and benefits (FDA drug development process). In the European Union, the EMA frames clinical trials as research studies that involve people and are governed by strict ethical and scientific rules (EMA on clinical trials). The point for sponsors is simple: the more a trial asks of people, the more carefully those demands need to be justified.
How to reduce the burden
Strategies to reduce participation burden fall into three categories. First, reduce visit frequency: schedule fewer in-person visits by using telehealth for follow-ups, remote monitoring, and home health visits. Second, streamline procedures: use central labs instead of requiring multiple site visits, combine tests into single sessions, and use electronic diaries with reminders. Third, provide support: offer travel reimbursement, flexible scheduling, evening and weekend appointments, and compensation for time.
Decentralized clinical trials represent a major shift in this direction. Instead of requiring all visits at a central site, decentralized trials use local labs, home health nurses, telemedicine, and wearable devices to collect data remotely. Participants may only need to visit the site once or twice, or never at all. Decentralized trials gained momentum during the COVID-19 pandemic and are now a standard option for many study designs. They reduce geographic barriers and make participation possible for patients who cannot travel.
Measuring what you cannot see
Researchers measure participation burden with several tools. Patient burden assessments ask participants to rate the difficulty of each trial procedure. Visit burden questionnaires measure time, travel, and inconvenience. Dropout rates are a key indicator: high dropout suggests excessive burden. Qualitative interviews reveal what participants find most challenging. Measuring matters because researchers often underestimate the demands they place on participants. What seems reasonable to the study team may feel overwhelming to the patient.
The bottom line
Participation burden is real and significant. Time, physical, psychological, financial, and logistical demands all contribute to dropout, and ignoring them undermines recruitment, retention, and data quality. Decentralized trials and telehealth can dramatically reduce burden: fewer site visits, remote monitoring, and home health visits make participation feasible for more patients. Measuring and addressing burden is every researcher's responsibility. Ask participants what they find burdensome, then design trials that minimize demands without compromising scientific quality. Every eliminated visit is one less day of disruption. Every dollar of travel reimbursement makes participation more accessible. The best trials are designed with the participant experience in mind from the very beginning.
This article is based on the Clarity Clinical Solutions video "Participation Burden - What does it really take to participate." Watch it here: Participation Burden - What does it really take to participate
References
- Clarity Clinical Solutions — "Participation Burden - What does it really take to participate" (source video). https://www.youtube.com/watch?v=M4hEN12v71I
- ClinicalTrials.gov — Why should I participate in a clinical trial? https://clinicaltrials.gov/about-studies/why-should-i-participate
- FDA — The drug development process (patients page). https://www.fda.gov/patients/learn-about-drug-and-device-approvals/drug-development-process
- EMA — Clinical trials in human medicines (research and development). https://www.ema.europa.eu/en/human-regulatory/research-development/clinical-trials-human-medicines