Clinical trial participation options: A practical evidence-based guide

Want to be in a clinical trial? Here is what to know about the hurdles, participation formats, and questions that can shape an informed decision. Finding a suitable study is only the first step, because location, eligibility, time, financial considerations, and follow-up requirements can determine whether participation is realistic. 1

Why participation can be difficult

Clinical trials are central to developing medicines, devices, procedures, and other interventions, yet many interested patients are never connected with an appropriate study. In an online survey of more than 2,000 adults with chronic conditions, 71% said they would be likely to participate if given the opportunity, while two-thirds said a healthcare provider had never discussed trials with them. A study using 2020 data found that only 9% of adults reported ever being invited. 1

Recruitment creates additional system-wide friction. One estimate cited in reporting indicates that up to 86% of clinical trials do not meet recruitment targets within the planned trial period. Even when a study appears relevant, a person may live too far from its site, lack transportation, have work or caregiving obligations, or discover that a medical history does not meet the protocol. Retention can remain challenging after enrollment because visits and monitoring continue over time. 1

Types of clinical research participation

Clinical research includes interventional studies, in which investigators assign a treatment, procedure, device, or other intervention, and observational studies, in which researchers collect information without assigning an intervention. Both people with a medical condition and healthy volunteers may qualify, depending on the study's inclusion and exclusion criteria. These criteria can include age, diagnosis, prior treatment, laboratory findings, location, and other protocol requirements. 2

Interventional studies are often described by phase. Phase 1 primarily examines safety and dosing, Phase 2 evaluates effectiveness and side effects, Phase 3 compares an intervention with a control or existing approach, and Phase 4 collects information after marketing authorization. The phase does not by itself determine whether participation is appropriate. The study's purpose, procedures, uncertainties, alternatives, and a person's circumstances require separate consideration. 3

Ways to find a study

In the United States, ClinicalTrials.gov allows searches based on condition, intervention, location, recruitment status, age, and other study characteristics. A search result is not an invitation or a determination of eligibility. The listing may require confirmation from the research team, and recruitment status can change as enrollment targets, protocol requirements, or site capacity change. 4

People with cancer can use National Cancer Institute resources to identify studies relevant to diagnosis, treatment history, location, and eligibility. Healthcare professionals, patient advocacy organizations, and research institutions may also know about studies that match a particular condition. The available evidence shows why provider discussion matters, but prospective participants still need to verify details directly with the responsible study team and treating clinician. 5

Consent, oversight, and participant rights

Before enrollment, an informed-consent process should explain the study's purpose, procedures, foreseeable risks, potential benefits, alternatives, confidentiality protections, contacts, and compensation or costs. Consent is a communication process rather than merely a signature. Prospective participants can ask how often visits occur, what information is collected, what happens if a result is abnormal, and whether treatment assignments may include a placebo. 6

Participation is generally voluntary, and participants may ask questions or withdraw without losing their regular medical care. An institutional review board or similar ethics committee reviews covered human-subject research to help protect participant rights and welfare. Oversight does not mean that a study is risk-free, that an investigational intervention will work, or that an individual will personally benefit. 7

Remote, site-based, and hybrid options

Participation arrangements vary considerably. Traditional studies may require visits at a hospital, university, clinic, or research center for examinations, laboratory work, dosing, or interviews. Decentralized studies can conduct some activities away from a traditional site through remote visits, digital tools, local services, or home-based procedures. The exact arrangement depends on the protocol, the intervention, safety monitoring, and applicable requirements. 8

Examples in the research data show how formats differ. Scripps Research described a Long COVID treatment study for U.S. residents using remote participation, smartphones, activity trackers, smart scales, and health-record sharing, although eligibility verification for that study later closed and a waitlist was offered. The EJS ACT-PD Parkinson's study describes appointments either at a local site or remotely, with visits every six months, additional appointments, telephone calls, questionnaires, and video assessments over as long as 36 months. 9

Costs, compensation, and ongoing obligations

Financial arrangements differ by protocol and should be discussed before consent. Questions can include whether study visits, laboratory tests, medications, travel, lodging, parking, routine-care services, or treatment for research-related injury are covered. Compensation may be offered for time and travel, but its amount, schedule, tax treatment, and eligibility conditions vary. A research site should explain which expenses remain the participant's responsibility. 1

Participation can also require sustained attention. A person may need to take study medication as directed, record symptoms, attend scheduled visits, use monitoring devices, report side effects, complete questionnaires, or maintain contact with coordinators. Remote participation can reduce travel while adding technology and data-sharing responsibilities. A study's convenience should therefore be assessed alongside privacy, workload, uncertainty, and the possibility of assignment to a placebo or comparison group. 10

Alternatives when a trial is not suitable

A study may be unsuitable because of eligibility criteria, geography, timing, health status, competing treatment, or personal obligations. People should not change prescribed treatment or delay standard medical care solely to pursue research participation. A treating clinician can help interpret whether a study's procedures and risks fit the person's medical situation, while the research team can clarify protocol-specific requirements. 3

For some people with serious or immediately life-threatening disease who cannot participate in a suitable trial, FDA expanded access may be a possible pathway to an investigational medical product when regulatory, clinical, and safety conditions are met. Expanded access is not the same as enrollment in a controlled clinical trial and does not guarantee benefit. It requires separate evaluation involving the patient, treating physician, manufacturer, and applicable oversight processes. 11

Sources

1. The Philadelphia Inquirer and KFF Health News, “Want to be in a clinical trial? Here’s what to know.” https://www.inquirer.com/health/clinical-trial-how-to-join-what-to-know-20260826.html
2. ClinicalTrials.gov, “Study Basics.” https://clinicaltrials.gov/study-basics
3. U.S. Food and Drug Administration, “Clinical Trials: What Patients Need to Know.” https://www.fda.gov/patients/clinical-trials-what-patients-need-know
4. National Institutes of Health, “NIH Clinical Research Trials and You.” https://www.nih.gov/health-information/nih-clinical-research-trials-you
5. National Cancer Institute, “Joining a Clinical Trial.” https://www.cancer.gov/research/participate/clinical-trials
6. U.S. Department of Health and Human Services, “Informed Consent.” https://www.hhs.gov/ohrp/regulations-and-policy/guidance/informed-consent/index.html
7. U.S. Food and Drug Administration, “Institutional Review Boards Frequently Asked Questions.” https://www.fda.gov/regulatory-information/search-fda-guidance-documents/institutional-review-boards-frequently-asked-questions-information-sheet
8. U.S. Food and Drug Administration, “Decentralized Clinical Trials for Drugs, Biological Products, and Devices.” https://www.fda.gov/regulatory-information/search-fda-guidance-documents/decentralized-clinical-trials-drugs-biological-products-and-devices
9. Scripps Research and EJS ACT-PD study materials. https://longcovid.scripps.edu/locitt-t/ and https://www.ejsactpd.com/about-us/about-ejs-act-pd-trial/
10. ClinicalTrials.gov and participant information described in the supplied research data. https://clinicaltrials.gov/study-basics
11. U.S. Food and Drug Administration, “Expanded Access.” https://www.fda.gov/news-events/public-health-focus/expanded-access