skip to content »

Neurology - Alzheimers

Houston, Texas

The Cullen Building at Baylor College of Medicine.
Department of Neurology
not shown on screen

Understanding Clinical Trials

A clinical trial is a research study designed to answer specific questions about new medications, therapies, or new ways of using known treatments. Carefully conducted clinical trials enable researchers to determine if new treatments are both safe and effective. All clinical trials are based on a set of rules called a protocol. A protocol describes factors such as eligibility, what procedures will be involved, how many study visits will take place, the duration of the study, and what investigational drug or approved medication will be studied. It also determines whether or not patients can take standard therapies while in the study, and whether or not a new therapy will be compared to a placebo (inactive pill) during the study. While in a clinical trial, participants are seen regularly by the research staff to monitor their health and to determine the safety and effectiveness of the potential treatment.

Who Can Participate in a Clinical Trial?

All clinical trials have strict guidelines about who is eligible to enroll. These guidelines may include factors such as age, past medical history, present medical condition, and current medications used. Before you are accepted into a clinical trial, you must first meet certain eligibility requirements (“inclusion criteria”) specific to that study. While some research studies do recruit healthy volunteers, many clinical trials need individuals who have certain medical conditions in order to assess new treatments for these conditions. It is important to keep in mind that the inclusion criteria specified in the protocol are not means by which potential subjects are rejected personally or intentionally prevented from participating in research opportunities. Instead, these criteria are used to identify appropriate participants, ensure their safety, and enable the investigators to answer their research questions.

Who Sponsors Clinical Trials?

Clinical trials may be sponsored by government agencies such as the National Institutes of Health (NIH), pharmaceutical companies, individual physicians or investigators, or health care institutions such as health maintenance organizations (HMOs) that develop medical devices or equipment. Clinical trials may be conducted in a variety of locations such as hospitals, universities, medical schools, physicians' offices, or community clinics.

How are Research Participants Protected?

The government has strict guidelines and safeguards to protect people who participate in clinical trials. Every clinical trial conducted in the United States must be approved and monitored by an Institutional Review Board (IRB) to ensure that any risks are as low as possible and that the potential benefits of participation outweigh the potential risks. An IRB is an independent committee of physicians, statisticians, community advocates, and others who work together to ensure that a clinical trial is ethical and that the rights of participants are protected. All institutions that conduct or support biomedical research involving people must, by federal mandate and regulation, have an IRB that initially approves and periodically reviews the research study. This includes carefully analyzing the details and circumstances of any serious side effects that may arise during the course of a clinical trial.

What is a Placebo?

A placebo (or “sugar pill”) is a pill that looks identical to the study drug but contains no medication or active ingredients. Clinical trials often involve comparing the experimental treatment with a placebo in order to determine effectiveness. In a placebo-controlled study, one group of subjects receives the investigational drug while another receives a placebo. Studies of this kind are necessary in order to determine if the medicine or study drug being tested is more effective or beneficial than receiving no treatment at all, or standard therapy without the new agent.

What is a Randomized Study?

This is a clinical trial in which participants are randomly (meaning by chance, like flipping a coin) assigned to receive either the investigational drug or the placebo.

What is a Blinded Study?

This is a study in which the participants are not allowed to know what group they have been assigned. In other words, they cannot be told if they are receiving the investigational drug or a placebo.

What is a Double-Blind Study?

This is a study in which neither the participant nor the research staff is allowed to know if the participant is receiving the study drug or the placebo during the study. Studies of this nature are designed so that neither the subject's nor the researcher's expectations about the study can influence the outcome of the study.

What are Adverse Events?

Any undesired effect or consequence of the study drug or any medically important event occurring during the trial is considered an adverse event or possible side effect. Depending on the clinical trial and the potential treatment being tested, potential side effects could include various symptoms such as headache, nausea, dizziness, skin irritations, etc…All side effects (whether minor or severe) are reported during the course of the clinical trial, and are closely monitored and reviewed in order to safeguard the health of the study participants.

What is Informed Consent?

This is the process by which essential facts of the study are explained before a person makes a decision to participate in the study. Because joining a clinical trial is an important decision, potential subjects are first given a consent form to read in full which describes the study, the potential risks and benefits, what will be required of the subjects during the trial (i.e., the number of visits you must make, if any lab work will be required, if there is any cost to the participant, etc…). The research staff will review the consent form with you. All potential subjects are encouraged to discuss any concerns or ask any questions of the research staff about the study. Individuals considering research trials are also encouraged to talk over their decision with family members, friends, or their primary physician before consenting to participate in a study. Those subjects who meet the inclusion criteria and do not meet the criteria for exclusion who then choose to enroll in a trial will be asked to sign the consent form that they read and had explained to them. No research procedures will be conducted before you have an opportunity to read the consent form, have it explained to you by the research staff, and agree to give your consent by signing the consent form. Participants will be given a copy of the signed consent form so that they may refer to it and review the details of the study at any time. A consent form is not a legal contract. Study subjects are allowed to withdrawal from a clinical trial at any point in the trial.

The following questions should be answered by the researchers during the informed consent process:

  • What is the purpose of the study?
  • Who is sponsoring the study?
  • Who has reviewed and approved the research protocol?
  • Why do researchers think that the investigational treatment may be beneficial?
  • What kinds of procedures or tests are involved as part of the study?
  • How do these procedures compare with those normally performed at my regular visit to the doctor?
  • How long will the trial last and how often do the study visits occur?
  • Who will provide my medical care while I am in the study and after I complete it?
  • Will I be able to take my regular medications during the trial?
  • What medications or procedures (if any) must I avoid while in the study?
  • What are my responsibilities as a study participant?
  • Will the researchers be in contact with my primary care physician?
  • Will I be able to find out the results of the study?
  • Are any possible risks or side effects anticipated as a result of participating in the trial?
  • What other treatment options do I have?
  • Will I have to pay anything to participate in the study?
  • How do the potential risks and benefits anticipated with the investigational treatment compare with those related to already approved treatments currently available?

What are the Possible Benefits and Risks Associated with Clinical Trials?

Participation in a clinical trial may allow you to take a more active role in your own health care. It may allow you to gain access to the newest treatments not yet available to the general public. You may obtain expert medical care at leading health care facilities over the duration of the trial. And, you may help others by contributing to medical research.

Potential risks involved may include possible unanticipated side effects or adverse reactions to the investigational treatment. A lack of direct personal benefit may result if you are in the group that was assigned to receive a placebo instead of the study drug. There is the possibility that the investigational drug shows no benefit and is determined by the trial to be ineffective. Other potential risks may include expended time and effort necessary to participate in a clinical trial.

Additional Information on the Clinical Trials Process

E-mail this page to a friend