Understanding Clinical Research – An Introduction to Clinical Trials

What is clinical research? What are clinical trials?

Clinical research is the process of studying diseases, and developing medications to possibly prevent, treat, or help relieve symptoms caused by different medical conditions. Before a medicine can become widely available, it must be tested in a series of clinical trials, or clinical research “studies.” The medicine being studied or tested in a clinical trial is called an “investigational medication.”

Most clinical trials recruit volunteers to participate in the study. Those volunteers are closely monitored to follow the effects of an investigational medication on their health, and that information is used by health authorities to determine if the investigational medications are safe and effective, and whether they should be approved for routine medical use.

How do clinical trials work?

Clinical trials usually go through three phases before an investigational medication can be approved for general use:


Healthy volunteers receive the investigational medication to help researchers study the initial safety, and understand how the drug is processed by the body. Some phase 1 trials will include people with the disease after initial results are evaluated from healthy volunteers.


The investigational medication is given to a small number of people with the disease to learn more about how safe it is and how it is processed by the body. These trials may also evaluate different doses to determine which should be studied further in future trials.


These trials include a larger number of people, and are intended to generate enough information to establish whether the investigational medication can safely be administered, and whether it provides sufficient benefit to be made available to the public.

Why do people participate in clinical research studies?

There are numerous reasons to participate in a clinical trial, but some of the main reasons include:

  • Participants may receive an investigational medication before the drug has been approved for general use.
  • By participating in clinical trials participants can have an impact on the life of someone else who suffers from the same condition by helping researchers advance medical science and increase treatment options. Clinical trials play a valuable role in the development of new medications, and participants help the medical community find new ways to treat disease.

It’s important to remember that clinical trials involve some risks, including:

  • There may be limited information about the safety or effectiveness of an investigational medication, including whether it works at all, or what side effects it could cause.
  • Participants may not see improvement, or improvement may take several months or more to appear.
  • In some participants their condition could even get worse.

For these reasons trial participants are screened carefully, and all clinical trials involve careful monitoring throughout all phases of the trial.

Some trial participants also feel the additional time and support they receive from study doctors and investigators during the study helps them learn more about their condition. But whatever the motivation, study participation is entirely voluntary, and participants can choose to leave the study at any time, for any reason, if they change their mind.

Understanding Clinical Research Terms

Clinical research terminology can be intimidating. We have created this glossary of clinical trial language to help you understand some of the key terms:

Single-blind, double blind In a “single-blind” study, the study participant does not know whether they are receiving the investigational medication, an alternative therapy, or a placebo, but the study team does. In a “double-blind” study, neither the participant nor the study team knows which treatment is being given.
Clinical trial participants People who volunteer, meet eligibility criteria, and choose to take part in a clinical trial.
Eligibility criteria The requirements for who can participate in a clinical trial. These can include age, diagnosis, current and previous treatments, allergies, and other conditions.
Genetic testing Genetic testing (also known as DNA testing) allows doctors to determine the presence of genetic indicators of hereditary diseases (see definition below). Genetic testing can be conducted on a sample of blood, saliva, skin, or other tissue that contains the subject’s DNA.
Hereditary disease Any disease where the defining characteristics or causes are inherited from the parents. In many cases genetic testing (see above) can be used to determine whether a specific disease-indicating gene runs in a family.
Independent ethics committee (IEC) or institutional review board (IRB) Independent committees made up of medical experts and the general public, who review, approve, and monitor all aspects of clinical research studies involving people. These groups ensure study protocols adhere to all relevant regulations, and that the rights and welfare of all participants are protected.
Informed consent form (ICF) An important written document that is part of a larger “consent process” discussion with the study team. The ICF describes the study, including potential risks. By signing the ICF, patients agree to participate. Parents or guardians must sign for minors to participate in a clinical trial, however the child may be asked to sign a simplified “Assent Form” to show they understand and are participating voluntarily.
Investigational medication A medicine being studied in a clinical trial. Typically this medication is not yet approved for general use for the condition being studied.
Open-label, open-label extension In an open-label study, or open-label extension (continuation of the study) both the study team and the participants know which treatment is being administered.
Placebo A substance that looks like the investigational medication, but has no active medication. Placebos are used to compare the effectiveness of the study medication against no treatment.
Protocol A detailed plan describing the purpose of a study, how the study will be conducted, who can participate, the investigational medication that will be administered, and how the effects will be monitored.
Randomization “Randomized” clinical trials assign participants at random to groups or “cohorts” within the trial, with each group receiving a different treatment regimen. The different regimens may include some combination of the study medication, a placebo, and/or other alternative therapies. Randomization is important in gathering clear, unbiased results. Not all studies involve placebos, alternative therapies, or randomization. If a particular study is randomized, patients will be made aware before agreeing to participate.
Study team, or study site team The doctors, nurses, and other professionals who are conducting a study at a particular clinic or hospital. The doctors may also be referred to as “investigators” for the study.