Understanding investigative clinical trials.

This article reviews the background, rationale, and principles of clinical trials and their role and influence on medical practice. The relationship of clinical trials to other forms of clinical studies is explored. The fundamentals of sound design, analysis, interpretation, and reporting of clinical trials are detailed. Ethical issues, costs, and limitations of trials are explored. The article reviews the trends in program content of 749 abstracts presented at the joint vascular surgical meetings during the past 17 years, demonstrating a significant increase in reported clinical trials during the last half of this period. Finally, future trends in the use of clinical trials to "validate" medical practice are suggested in response to efforts to control rising health care costs. Physicians, including vascular surgeons, must become knowledgeable in the principles of clinical trials to interpret more effectively, apply, or even participate in such clinical research.