The ethics of randomized clinical trials.

Randomized clinical trials pose a number of fundamental ethical problems to which morally sensitive investigators must give careful consideration. The randomized double-blind clinical trial is ethically justified and the preferred method of demonstrating therapeutic effectiveness and safety. Alternate methods such as crossover and self-controlled designs, the use of historical controls, observational methods, and practitioner's clinical trials also exist and have their place in certain circumstances. The use of randomized double-blind clinical trials must assure adequate explanation of the research plan to the patient, the documentation of informed consent, adequate consideration of safety, and an acceptably low risk/benefit ratio.