Clinical trials are how we determine which medical interventions make the most difference. By testing them on volunteers, we can see first-hand how these interventions work in the real world, helping us continually develop improved ways for delivering care.
During a clinical trial, scientists administer a new drug, procedure, device, or type of treatment to volunteers, then measure the results. These interventions may be evaluated by themselves, or they may be compared against other interventions or even placebos.
The path to clinical trials begins with basic research. This is when scientists try to gain a general understanding of a medical problem. The next step is translational research, which builds off the findings from basic research and determines which interventions are most likely to work. Finally, clinical trials take this knowledge and test it on human volunteers, making it possible to discover the safest and most effective drugs, procedures, devices, or other medical treatment.
Reasons for conducting clinical trials may include the following:
- Prevention: Discovering a successful method for preventing a disease or condition from developing.
- Diagnosis: Measuring the effectiveness of new methods for diagnosing or identifying a disease or condition.
- Screening: Testing the best ways to detect specific diseases or conditions.
- Treatment: Measuring the effectiveness of using a drug, procedure, or other medical therapy or product to treat a disease, condition, and/or symptom.
- Quality of Life: Measuring the effectiveness of new methods for improving the quality of life of patients with a disease or condition.
In general, researchers begin by outlining the objectives of the trial, then specifying how it will be designed to meet those objectives. Afterwards, they recruit volunteers who meet the criteria for the trial, administer the drug or treatment, and monitor the results.
Types of Clinical Trials
In order to ensure accuracy and remove any possible bias, there are several different types of clinical trials.
- Prospective Trial: Patients are identified and then followed over time.
- Randomized Trial: Patients are randomly placed into either a treatment group or a control group. Those in the treatment group receive the new treatment, while those in the control group do not. The results of both are then compared.
- Crossover Trial: Patients receive either the standard treatment or a placebo, as well as the new treatment, but at different times. Their responses to both are carefully monitored and compared.
- Double-Blind Trial: Patients receive either the treatment or the placebo, but neither they nor the researchers know which one the patient gets.
- Open-Label Trial: Patients receive either the treatment or the placebo, and both they and the researchers know which one the patient gets.
To ensure that all clinical trials are ethical, that the rights of the participants are protected, and that all participants are fully informed, an independent committee composed of physicians, scientists, and non-scientific experts called an Institutional Review Board (IRB) approves and monitors every clinical trial in the United States. Read more about IRBs and their functions.
Phases of Clinical Trials
To make it easier for researchers to answer one question or focus on one problem at a time, clinical trials are typically broken down into four distinct phases.
The purpose of this phase is to determine the safety of the drug, device, or treatment for the first time in humans. Researchers usually use a small group (20 to 80 people) of healthy volunteers to investigate specific effects or characteristics of the intervention, such as its side effects.
This phase evaluates the efficacy of the intervention, or whether it produces an intended effect. Researchers test it on a larger group (100 to 300 people), often using randomized trials in which one group receives the intervention while another receives either a standard drug or treatment or a placebo. This phase can last for several years.
In this phase, researchers begin looking at the efficacy and safety of the intervention on a larger scale, as well as its effectiveness, or whether it produces any therapeutic benefit. Larger groups (1,000 to 3,000 people) are used during this phase so that researchers can better evaluate side effects, compare the intervention against existing drugs, devices, or treatments, and look at its effectiveness across different populations.
If the Food and Drug Administration (FDA) approves the results of this phase, the intervention can be introduced to the general public.
Also known as postmarketing surveillance, this phase takes place after a drug or treatment has been introduced to the market. The goal is to evaluate the intervention’s long-term effectiveness and compare it against other interventions already on the market.
Every clinical trial will have different requirements for participation. Some trials look for people with specific conditions, while others seek healthy people without preexisting conditions. Most trials will specify both inclusion criteria (characteristics a participant must have) and exclusion criteria (characteristics a participant must not have).
Common criteria for both inclusion and exclusion may include the following:
- Family history
- Genetic profile
- Treatment history
- Type and/or stage of a disease
Before a trial begins, researchers will carefully screen each participant to ensure they meet their criteria. This screening may also involve cognitive and physical tests. Making sure everyone fits the study criteria is a critical part of producing meaningful and reliable results.
Benefits and Risks of Participating
Participating in a clinical trial is completely voluntary. However, there are a number of reasons why someone may want to participate:
- Gain early access to new and experimental treatments
- Help prevent a disease or condition that affects a loved one or family member
- Play a more active role in one’s own health care
- Help researchers gain a better understanding of a disease or condition
- Contribute to future medical breakthroughs that benefit the public
However, participation can also come with risks. These may include uncomfortable side effects, ineffective treatment, becoming part of a control group that receives the standard intervention or no intervention at all, and the general inconvenience of participation. Because of this, volunteers should speak with their healthcare provider about any of their concerns.
How Do I Participate?
Clinical trials are an important aspect of Columbia Surgery’s research. We are regularly running several dozen clinical trials at various phases.