For more information on the clinical trial featured in this episode of CURIOUS, please refer to the Clinical Trials Web site for IT-101.
What is a clinical trial?
Clinical studies are integral to our understanding and treatment of diseases and medical conditions. There are two basic types of clinical studies: observational and interventional.
An observational study is designed to find out about the development or effects of a medical condition. Probably the most important observational study ever conducted was the Framingham Heart Study, which began in 1948 and is still ongoing. Researchers enlisted over 5,000 residents of Framingham, Massachusetts who had not suffered heart attacks or other cardiovascular problems. The objective was to discover how heart diseases started, developed, and eventually caused death. Participants have been given regular examinations and their data have been compared to find factors that were common among those who developed heart disease and rarely found among those who remained healthy. Characteristics (also known as risk factors) that were identified included high blood pressure, high cholesterol, excess weight, and a lack of physical activity.
An interventional study, or clinical trial, tests whether an intervention with a particular therapy will improve a particular condition. Findings from the Framingham Study have led to countless interventional studies to test the effects of diet and exercise programs on reducing weight, blood pressure, and cholesterol levels, as well as trials of new drugs to reduce blood pressure, cholesterol, and obesity. Follow-up studies have shown that these interventions not only improve risk factors but also can slow or stop disease progression and allow people to lead longer, healthier lives.
Clinical trials are conducted to investigate new drugs, medical devices such as pacemakers or artificial joints, innovative surgical procedures, and specific nonmedical procedures such as a psychotherapeutic technique for a certain condition. In addition, a clinical trial may directly compare two or more established drugs in treating the same illness or study a drug approved for one disease in the treatment of another.
How does a clinical trial work?
Every clinical trial is designed to measure specific effects of a treatment on a disease. For example, the primary endpoint, or main goal, when studying a cancer treatment might be to determine whether it helps patients live longer than currently available treatments. Secondary endpoints might be to establish whether it shrinks tumor size or prevents the spread of cancer to other organs.
Individuals must be told about the study in detail — including any potential risks or benefits involved — and sign a document of informed consent before being included in the study. Patients are not under contract. They may choose to leave a clinical trial at any time.
A clinical trial must have at least one treatment group and one control — or comparator — group. Patients are randomly assigned to one of the groups, and in most trials they aren’t told which they’re in. Only patients in the treatment group actually receive the treatment being studied. Those in the control group may receive either a placebo, which contains no real medicine, or a standard treatment already on the market.
Clinical trials follow strict ethical standards. Patients are not given placebo alone if withholding treatment would allow their condition to worsen or endanger their health.
Why participate in a clinical trial?
There are many reasons to take part in a clinical trial. Perhaps the most obvious benefit is access to new treatments that aren’t yet on the market. This may be especially important for those with life-threatening or chronic illnesses when conventional treatments are ineffective or cause troublesome side effects. Also, clinical trials are usually conducted in major health care facilities by physicians who are leaders in their fields, so patients may feel that they will receive better care in a clinical trial. Patients may also benefit emotionally by taking an active role in their treatment, or from knowing that they may help others by contributing to medical research.
What are the disadvantages of taking part in a clinical trial?
All medications have side effects, and an important part of a clinical trial is finding out what the long- and short-term side effects of a drug may be. Side effects may include headache, nausea, hair loss, rash, or other physical or psychiatric problems. Serious or life-threatening side effects sometimes occur.
Also, experimental treatments may not work as well as treatments already on the market. And not all patients in a clinical trial are given the treatment being studied. Some patients may receive a placebo (dummy pill) or another therapy against which the study drug is being compared.
Finally, clinical studies are often more time-consuming than simply being treated by one’s own doctor or local medical facility. Study participation may require longer travel to the medical center where the study is being done, more visits to the doctor, or more frequent or more complicated treatment.
Who can participate in a clinical trial?
In order to participate in a clinical trial, patients must first meet a wide range of eligibility criteria pertaining to age, gender, overall health, medical history, other medical conditions, and type and stage of the disease being questioned. Following these criteria helps both to ensure the accuracy of trial results and to protect the safety of trial participants.
For more information about clinical trials, visit www.clinicaltrials.gov, a Web site operated by the National Institutes of Health. This site includes complete information on clinical trials and how to participate in one, as well as an extensive database describing all current clinical trials and contact information for study coordinators.