Clinical Trials and Medical Progress

Thomas L. Petty, M.D.

Professor of Medicine, 
University of Colorado

Chairman, National Lung Health Education Program (NLHEP)


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Clinical Trials and Medical Progress.

May 1997
PEP Pioneers
Second Wind
Torrance, California

     Dear Friends:

     Almost everyone who reads this month's newsletter will have benefited from what is known as controlled clinical trials. Clinical trials are basically a form of human experimentation, which is highly desirable in order to make medical progress. So-called randomized, controlled clinical trials have become the gold standard in evaluating both drugs and medical devices. What randomization means is that patients are allocated by chance to either an active therapy or an inactive one known as a placebo, or to different active therapies in order to see which one is best. The classic randomized controlled clinical trial is usually done under A double-blind conditions. Thus, neither the patient nor the physician who is conducting the trial knows whether the patient is receiving an active drug or a placebo or, in the case of two or more active drugs, which one is being given. This eliminates bias from the study. Thus, clinical benefit or lack of benefit can be judged subjectively, i.e., relief of a symptom such as shortness of breath, pain, or anxiety, on the basis of what the patient reports or by measurements if a body function is involved. Since patients are the only ones who know how they feel, they have to tell physicians their own observations about benefit from the study. There is no way to measure symptoms. It is commonplace to measure airflow in response to bronchodilators and anti-inflammatory drugs, however.

     The guiding principle behind controlled clinical trials is that they must be ethical. Since both patients and physicians alike may be biased toward something new or innovative, the possibility of conflicts may arise. Thus the ethics of the controlled clinical trial must always include the patient's best interests and the principle of informed consent. Informed consent means total truth-telling about the pluses and minuses of any form of therapy or medical device under study. Both patients and physicians must try to avoid conflict of interests during the conduct of controlled clinical trials. It was a controlled clinical trial that first proved that drugs were effective in the treatment of tuberculosis. In the modern era, controlled clinical trials are showing benefits in cancer chemotherapy, in the treatment of AIDS and other life-threatening disorders. But for controlled clinical trials, medicine would stand still. Accordingly, this form of human experimentation is definitely desirable but must always be conducted within the concept of equipoise. Equipoise means that a new therapy could be good, bad or indifferent compared with an alternative therapy or no therapy at all. The proper conduct of controlled clinical trials requires the ultimate of care and integrity on the part of everyone. 

     I personally applaud the clinical investigators who work often tirelessly in the conduct of clinical trials, but most of my appreciation goes to the patients, who are the participants in moving medicine forward. Please keep up the good work. I will be in touch next month.

    Your friend,

   Thomas Petty, MD

Last update:
17 March 2002