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Therapy Session

What is Clinical Research?

Clinical research refers to the study of human health and disease. We can study medicine at many levels. For example, the bacteria that cause disease can be viewed through a microscope and studied, or researchers can use mice to study a disease process that affects humans. The key feature of clinical research is that it involves the study of humans.

What are the different types of Clinical Research?

Human studies can vary depending on what the researchers are interested in learning. Types of clinical research include:

  • Treatment studies – evaluating which medical interventions work best for a disease

  • Prevention studies – evaluating how to prevent a disease from starting or progressing

  • Diagnostic studies – evaluating how best to reach a medical diagnosis

  • Genetic studies – evaluating which gene(s) cause, or increase risk for, a disease

  • Epidemiological studies – identifying patterns, causes, and control of a disease


Once the topic of the clinical research is determined, human subjects must be recruited to participate in the study. Recruitment (who, how, when, and where) is determined by the type of study. For example, a study of headache treatment in children will recruit young patients with headaches to participate. Since those patients need to be identified first, such a study might recruit young patients who are referred to a headache clinic for evaluation. In contrast, researchers conducting a study of stroke prevention would likely recruit adults who are at risk of stroke, but have not yet had a stroke. These individuals might be recruited from general family practice clinics, or through a newspaper advertisement. Importantly, both patients and healthy individuals can participate in clinical research studies.

Research Eligibility

There are several ways that researchers identify people who are eligible for a research study. Large studies might advertise in the newspaper or on television. Researchers from smaller studies typically identify patients from medical clinics, emergency rooms, or hospitals. Patients are individuals who have the disease or medical condition being studied. Healthy individuals also can be eligible for clinical research. There are several ways that a researcher might identify a group of healthy individuals for a study. Research eligibility means that an individual fulfills the specific study criteria for participation. For example, in a study of blood pressure changes with pregnancy, researchers might be looking for women (1) in the first trimester of pregnancy, (2) at least 18 years of age, (3) without prior high blood pressure, and (4) without other medical conditions. A woman meeting these criteria would be considered eligible for research.

Informed Consent

Several rules are in place to ensure that humans who participate in clinical research are treated ethically. At the core of these ethical rules are two basic principles: researchers must (1) do good (known as beneficence) and (2) do no harm (known as non-malfeasance). There are research ethics boards that approve, review, and monitor human research to ensure that these principles are upheld. In the United States, they are called Institutional Review Boards (or IRBs).

Informed consent is part of the ethical approach to good clinical research. Informed consent means that research participants (1) should know that they are participating in research and (2) should be informed about what will be expected of them. Once researchers identify an individual who is eligible for their study, the process of informed consent follows. Informed consent should include a verbal description of the study, a written description of the study (that is signed by the participant), and an opportunity to ask questions. Researchers cannot force individuals to participate; access to medical care cannot be used to encourage participation; they must make an effort to keep participant information confidential; and they must inform the participant that they can stop participating at any time. Some (but not all) studies will offer money or some other incentive to participate.

Why Participate?

There are several reasons why people choose to participate in research – the financial incentive, curiosity about research, and the desire to help others. Since the research participant does not always see the final result(s) of the research, it might not be obvious to them how helpful their participation was. When you review past posts and read future posts, keep in mind that we know what we know about a certain clinical topic because a group of people agreed to participate in clinical research. If you (or a family member) are asked to be in a study, please consider participating. Clinical research is how we learn more about human health and disease.

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