HFA encourages you to speak to your provider or HTC before participating in any clinical trial.
For a more in-depth look at clinical trials, visit the Research and Clinical Trials course in HFA's Learning Central.
What is a Clinical Study?
Any research study that assigns human participants or groups of humans to one or more health-related interventions to evaluate the effects. Interventions could include drugs, cells and other biological products, surgical procedures, radiological procedures or devices. There are two types—clinical trials and observational studies.
Participants receive specific interventions according to the research plan or protocol created by the investigators, which may include medical products, such as drugs or devices; procedures; or changes to participants’ behavior. Note: Some people who are not eligible to participate in a clinical trial may be able to get experimental drugs or devices outside of a clinical trial.
- May compare a new medical approach to a standard one that is already available or to a placebo that contains no active ingredients or no intervention.
- May compare two already-available interventions to each other.
- Investigators determine safety and efficacy by measuring certain outcomes in the participants. When a new product or approach is studied, it is not usually known whether it will be helpful, harmful or no different than available alternatives.
Investigators assess health outcomes in groups of participants who receive interventions, but participants are not assigned to specific interventions by the investigator as they would be in a clinical trial. Intervention Examples:
- Given medical products such as drugs or devices or procedures as part of their routine medical care.
- Observing a group of older adults to learn more about the effects of different lifestyles on cardiac health.
Reasons for Conducting Clinical Studies
In general, clinical studies are designed to add to medical knowledge related to the treatment, diagnosis and prevention of diseases or conditions. Some common reasons for conducting clinical studies include:
- Evaluating one or more interventions, like drugs, medical devices, approaches to surgery or radiation therapy, for treating a disease, syndrome or condition
- Finding ways to prevent the initial development or recurrence of a disease or condition. These can include medicines, vaccines, or lifestyle changes, among other approaches.
- Evaluating one or more interventions aimed at identifying or diagnosing a particular disease or condition
- Examining methods for identifying a condition or the risk factors for that condition
- Exploring and measuring ways to improve the comfort and quality of life through supportive care for people with a chronic illness
The Five Phases of a Clinical Study
- Early Phase 1 (Formerly listed as “Phase 0”): Exploratory study involving very limited human exposure to the drug, with no therapeutic or diagnostic goals. Examples would include screening studies and microdose studies.
- Phase 1: Studies that are usually conducted with healthy volunteers and that emphasize safety. The goal is to find out what the drug’s most frequent and serious adverse events are and, often, how the drug is metabolized and excreted.
- Phase 2: Studies that gather preliminary data on effectiveness, as in whether the drug works in people who have a certain disease or condition. For example, participants receiving the drug may be compared to similar participants receiving a different treatment, usually an inactive substance, called a placebo, or a different drug. Safety continues to be evaluated, and short-term adverse events are studied.
- Phase 3: Studies that gather more information about safety and effectiveness by studying different populations and different dosages, and by using the drug in combination with other drugs.
- Phase 4: Studies occurring after FDA has approved a drug for marketing. These including post-market requirement and commitment studies that are required of or agreed to by the study sponsor. These studies gather additional information about a drug’s safety, efficacy or optimal use.
What to Consider Before Participating in a Study
Participating in a clinical study contributes to medical knowledge. The results of these studies can make a difference in the care of future patients by providing information about the benefits and risks of therapeutic, preventative or diagnostic products or interventions.
Clinical trials provide the basis for the development and marketing of new drugs, biological products, and medical devices. Sometimes, the safety and the effectiveness of the experimental approach or use may not be fully known at the time of the trial. Some trials may provide participants with the prospect of receiving direct medical benefits, while others do not. Most trials involve some risk of harm or injury to the participant, although it may not be greater than the risks related to routine medical care or disease progression.
For trials approved by Institutional Review Boards, the IRB has decided that the risks of participation have been minimized and are reasonable in relation to anticipated benefits. Many trials require participants to undergo additional procedures, tests and assessments based on the study protocol. These requirements will be described in the informed consent document. A potential participant should also discuss these issues with members of the research team and with his or her usual health care provider.
Participants who have the illnesses or conditions that will be studied or healthy participants, or some studies are limited to a predetermined group of people.
Who is Eligible?
Factors are called “inclusion criteria.” Factors are based on age, gender, type and stage of a disease, previous treatment history, and other medical conditions.
Where Do Studies Take Place?
Studies take place in hospitals, universities, doctors’ offices and community clinics, depending on who is conducting the study.
How Long is a Study?
The length varies, depending on what is being studied.
Protections That Exist for People Participating in Studies
Informed consent is a process used by researchers to provide potential and enrolled participants with information about a clinical study. It protects participants and provides enough information for a person to understand the risks of, potential benefits of, and alternatives to the study.
Institutional Review Boards
Each federally-supported or federally-conducted clinical study, and each study of a drug, biological product or medical device regulated by FDA must be reviewed, approved and monitored by an institutional review board (IRB). An IRB is made up of doctors, researchers and members of the community, which make sure the study is ethical and the rights and welfare of participants are protected.
Continued Regular Care
While enrolled in a clinical study, participants continue to see their usual health care providers who work with the research team to make sure the study will not conflict with other medications or treatments.
What Questions to Ask Before Participating
Know as much as possible about the study and feel comfortable asking the research team questions about the study, the related procedures and any expenses.
- What is being studied and for how long will it last?
- Why do researchers believe the intervention being tested might be effective? Why might it not be effective? Has it been tested before?
- What will I have to do and is hospitalization required?
- What are the possible interventions that I might receive during the trial?
- How will it be determined which interventions I receive (by random selection, for example)?
- Who will know which intervention I receive during the trial? Will I know? Will members of the research team know?
- How do the possible risks, side effects and benefits of this trial compare with those of my current treatment?
- What tests and procedures are involved?
- Who will pay for my participation and will I be reimbursed for other expenses?
- What type of long-term follow-up care is part of this trial?
- If I benefit from the intervention, will I be allowed to continue receiving it after the trial ends?
- Will results of the study be provided to me?
- Who will oversee my medical care while I am participating in the trial?
- What happens if I am injured during the study? What Protections Exist for People Participating in Studies?