Learn about what patients may experience while taking part in a clinical trial.
Prescreening
Before a person can take part in a clinical trial, they are usually prescreened. The prescreening process enables the clinical investigator to check a patient’s eligibility to participate in the trial as described in the inclusion and exclusion criteria of the protocol. Thus, the prescreening stage facilitates an effective selection of the trial participants before any trial-related screening procedure is performed, and consequently reduces the number of screen failures.
The most frequent methods of prescreening are over the telephone and online, but it can be conducted in person if potential participants find out about the trial during a medical appointment. The prescreening interview includes general questions about patients’ interest in joining the trial, their willingness and capability to attend visits at the trial site, and the collection of information that may help to preliminarily assess trial eligibility, if necessary (e.g. patient height and weight).
Informed consent
Once a potential trial participant is identified, and they are willing to consider participating, the next step is to obtain their informed consent. To help potential participants make an informed decision about their participation in the trial, they are provided with a Participant Information Sheet (PIS). This document has ethical approval and contains details about the trial rationale and aim, the intervention being tested, potential risks and benefits, and trial-related procedures. The PIS covers the information that needs to be explained and discussed with potential participants and their legal representatives or parents, if applicable, before signing the Informed Consent Form (ICF). No trial-related procedure can be performed prior to obtaining the patient’s informed consent.
Screening
After the ICF is signed, the trial-related screening and any other procedure mentioned in the protocol can be performed. The information collected and procedures undertaken at screening vary from one trial to another, and may include: a review of the participant’s medical history, physical exam, measurement of vital signs, and specific laboratory analyses. When the screening results are available, potential participants will be informed if they are eligible to continue in the trial.
Participant allocation to trial groups
Participants may be assigned to trial groups (controlled trials), which most often include the treatment group, in which participants receive the trial intervention, and the control group, in which participants receive the standard-of-care treatment, placebo, or no treatment. Frequently, participants are assigned at random to trial groups (randomized trials).
In most trials, participants and/or research staff are not informed of the participants’ assigned trial groups, to prevent investigator bias when reporting participants’ results (blinding). The information may be disclosed to trial participants and research staff when the trial has been completed or anytime during the trial for safety reasons. In an open-label trial, the participants and research staff know what treatment the participants receive.
In most clinical trials, participants do not have to pay for any drug tested in the trial or any procedure involved. Throughout the trial, all the necessary assessments are provided at no cost.
Some trials may require the insurance company to cover the costs related to drugs, devices, or procedures. Information related to trial reimbursement is detailed in the Participant Information Sheet.
Conducting a clinical trial requires a multidisciplinary team typically consisting of physicians, research nurses, and other healthcare professionals. Collectively, their role is to perform any trial-related activities, such as continuously monitoring the participant’s health and condition throughout the trial, administering the trial drug as stipulated in the protocol, performing any trial-related procedures, reporting any side effects and outcomes, and maintaining contact with the Sponsor. During their participation in the trial, patient volunteers would mostly interact with the Principal Investigator, Sub-Investigator, and Clinical Research Coordinator.
The time commitment for participants in a clinical trial varies according to the trial phase and protocol. Usually, trial participants are invited to come to the trial site for a screening visit, followed by several evaluation visits. Once the testing of the intervention reaches its end, a follow-up visit may be required.
Some clinical trials require just a follow-up visit or a follow-up call, while others have longer follow-up periods with several visits at certain intervals. Details like the number of visits, their duration, and their purpose are explained in the Participant Information Sheet.
Other activities may include filling in questionnaires, keeping a research diary, and attending additional visits due to experiencing side effects.
Participation in clinical trials does not normally involve extensive traveling. When it does, trial-related travel costs for participants, legal representatives, and caregivers may be covered by the Sponsor. Supporting documents, e.g. receipts and tickets, may need to be provided. Details and conditions for the reimbursement are explained in the Participant Information Sheet.
Usually, a participant leaves the trial once their participation has ended. The trial itself may continue for longer. Patients may return to the care of their regular doctor and continue to receive the standard medical care for their condition.
At the end of a trial, the data collected throughout is collated and analyzed. The analysis aims to answer key questions related to the scope of the trial. The main findings may discuss drug safety, side effects, and efficacy of the tested drug, device, or procedure in comparison with the current treatment or placebo. The final results should be made available to everyone who took part in the trial by providing a lay language summary. The results are usually published in medical journals, presented at conferences, and/or issued as a press release by the Sponsor.
If a clinical trial phase has a positive outcome, the Sponsor may recommend progressing to the next phase, following consultations with regulatory bodies. When the results of several trials suggest that a potential new drug, device, or procedure works and has an acceptable safety profile, the Sponsor usually applies for marketing authorization (product license) to the competent regulatory agency (e.g. the FDA in the United States, EMA in Europe). Cost-effectiveness analysis is considered when deciding whether to grant marketing authorization. Following marketing authorization, national healthcare authorities run a cost-effectiveness analysis, at the country level, to recommend market access (product reimbursement). The cost-effectiveness analysis usually compares the new drug, device, or procedure with the current standard of care in terms of costs and benefits. It also considers physicians’ and patients’ preferences.
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