DEAR DR. GOTT: I often read in my newspaper or hear on television about clinical trials for different diseases. I even have a friend who has been asked to participate in one. Are they really on the level?

DEAR READER: Yes, they are, as long as the trials are done through reputable facilities by trained personnel. Researchers are always looking for better ways to treat and prevent disease. Most clinical trials are related to health and follow a predetermined protocol. Specific guidelines for participation include the type of disease, gender, age of a patient, prior treatment given and more. Doctors, nurses, social workers and other health-care professionals will monitor people at the beginning, during and end of each study.

There are both positive and potentially negative side effects involved. On the positive side, each participant gets to be actively involved in his or her own health care. We would be a healthier nation if we all took an active role in our own health issues. Professional medical care will be provided at leading health facilities by top-notch researchers in the field. Each participant will be on the cutting edge of new treatments, and will play a role in helping sufferers of the specific disorder being studied.

Risks include the possibility of additional time and attention being spent following protocol regarding when and how to take treatment or medication. Any experimental drug might not be as effective as desired and may carry serious unwanted side effects.

Most research is regulated by the federal government, and the safety of all participants is paramount. Confidentiality is also extremely important.

Before jumping to become a member of a test group, it is important to ask appropriate questions and make an educated decision. Will you be responsible for any expenses? How long will the study last? What is its purpose? Can it trigger a negative reaction, resulting in an exacerbation of your symptoms? What type of testing will be performed? If it involves a medication, what are the potential side effects? I could go on and on. A person can always drop out of a test study — however, once making the commitment, it would be more beneficial to see it to completion, if possible.

Clinical studies are sponsored by a number of federal agencies, such as the National Institutes of Health, medical organizations, foundations, pharmaceutical companies and physicians. Once researchers complete testing in a laboratory setting, often followed with animal studies, experimental treatments are moved into clinical trials. Often, one group (about half) of the participants will be given an experimental drug or treatment. The other half will be provided a placebo or standard treatment already utilized. No participant group has any knowledge of which group he or she is in.

There are four phases involved in clinical trials. Phase I is restricted to small groups of 20 to 80 people in order to evaluate proper dosage, safety and side effects. Phase II involves between 100 and 300 people to evaluate further the trial's safety. Phase III involves between 1,000 and 3,000 people with the purpose of collecting all information about effectiveness, side effects and safety. Phase IV advances to additional information regarding the benefits, risks and optimal use.

To give you related information, I am sending you a copy of my Health Report "Consumer Tips on Medicines." Other readers who would like a copy should send a self-addressed, stamped No. 10 envelope and a check or money order for $2 to Newsletter, PO Box 167, Wickliffe, OH 44092. Be sure to mention the title.

Dr. Peter Gott is a retired physician and the author of the book "Dr. Gott's No Flour, No Sugar Diet," available at most chain and independent bookstores, and the recently published "Dr. Gott's No Flour, No Sugar Cookbook."