These frequently asked questions and answers will provide basic information about clinical research and how you can participate in a study conducted at the University of Iowa.

Clinical Trials Overview

What is a clinical trial?

A clinical trial is a research study in which human volunteers (participants) are assigned to one or more interventions to help answer specific questions about new ways to prevent, diagnose, and treat diseases. Clinical trials allow researchers to work with patients with the exact condition they are trying to treat.

What is clinical research?

Clinical research is medical research that involves people to test new treatments and therapies. This type of research may test the effectiveness and/or safety of medications, medical devices, or other treatments. Some research studies are designed to observe and measure outcomes without having researchers affect the routine medical care of the volunteer.

What are the different types of clinical trials?

Treatment Trials
Test new treatments, combination drugs, or medical procedures.
Prevention Trials
Looks for better ways to prevent disease in people who have never had the disease or to prevent the disease from returning in people who were already diagnosed.
Diagnostic Trials
Finds better tests or procedures for diagnosing a disease or condition.
Screening Trials
Tests the best way to detect the presence of a disease or health condition.
Quality of Life Trials
Explores ways to improve comfort and quality of life for individuals with a chronic illness.

What do the different phases of trials mean?

Clinical trials take place in phases, and each phase helps researchers answer specific questions.

Phase I
These trials test new drugs, devices, or procedures to find out how safe they are and identify possible side effects. These are conducted in a small group of people (20-80).
Phase II
These trials of individuals with the disease or condition in question are used to further evaluate the efficacy and safety of a drug, device, or procedure. Researchers keep track of any medical benefits and side effects. These are conducted in a larger group of people (100-300).
Phase III
These large trials compare a new treatment or procedure to an existing treatment to determine which is more effective. Researchers continue to evaluate side effects and effectiveness. These are conducted in a large group of people (1,000-3,000).
Phase IV
Once a drug, treatment, or procedure is approved by the U.S. Food and Drug Administration (FDA) and made available to the public, researchers continue to study its safety to determine the best use of the new treatment in these post-marketing surveillance studies.

Who participates in clinical trials?

People with specific diseases or conditions and healthy volunteers can participate in clinical trials.

What happens during a clinical trial?

At the beginning of the trial, you will participate in the informed consent process and then the research team will assess your eligibility to participate.

They may check the health of each participant, take baseline measurements and give specific instructions about participating in the trial. The research team will monitor each participant at follow up visits and through surveys and interviews throughout the study. Some clinical trials involve more tests and doctor visits than you would normally have for an illness or condition.

Should I continue to work with my primary health care provider while in a trial?

Yes. Most clinical trials provide short-term treatments related to a specific illness or condition, but do not provide extended or complete primary health care. In addition, by having the health care provider work with the research team, the participant can ensure that other medications or treatments will not conflict with the protocol.

What happens after the trial?

After all participants have completed the study and all data collected from the trial are entered, the data is analyzed to determine the answers to the specific health questions posted by the study. The types of questions to be answered depend on the purpose of the study.

Considering Participating

What are the benefits and risks of participating in a clinical trial?

All medical research involves some risk. The risks and benefits are different for each clinical trial, so it is important that you talk to members of the research team before making a decision.

They can tell you about the known risks and benefits of the specific trial you are considering, as well as other available treatment options to help you and your loved ones decide whether or not to participate.

How do I find out if I qualify for a clinical trial about a specific disease or condition?

Every clinical trial has guidelines on who can participate, called eligibility criteria. To determine if you are eligible, study staff may screen you to see if you could participate if interested. In addition to the specific disease of condition, other criteria may include age, gender, previous treatments, and other known medical conditions or family medical history.

How long do clinical research studies last?

The length of a clinical trial or research study is different depending on the study. When volunteering for a trial, you will be told the duration before you decide to participate.

How does clinical research make a difference?

Clinical research and trials help researches learn about the safety and effectiveness of all drugs, procedures, and other treatments. Medical advances like new drugs and surgical procedures are possible because of clinical trials and the voluntary participation of individuals.

Make an Informed Decision

What questions should I ask if I am thinking about participating in a clinical trial?

The Office of Human Research Protections (OHRP) in the U.S. Department of Health and Human Services provides informational videos, a list of questions to ask and information about the protection of research participants and some additional resources.

The National Institute of Health (NIH) also provides a list of questions (from that you should ask to decide whether to participate in a clinical research study or trial.

Where else can I find information about clinical trials?

There are several national and University of Iowa websites that provide information about clinical trials, including:

How can I find out more about clinical trials offered at Iowa?

Please visit the Resources section of the website.


1. Glossary of Terms

2. National Institutes of Health Glossary of Common Terms

3. Office of Human Research Protections pages About Research Participation