TABLE OF CONTENTS Avicenna, an Arabian physician and philospher (980-1037), in his encyclopedic Canon of Medicine, set down seven rules to evaluate the effect of drugs on diseases. He suggested that a remedy should be used in its natural state, with uncomplicated disease, and should be observed in two contrary types of disease. His Canon also suggested that the time of action and reproducibility of the treatment effect should be studied (Crombie, 1952; Meinert, 1986).
But for several centuries Avicenna's advice appears to have been largely ignored, with most ideas affecting choice of treatment depending largely on serendipity rather then planned experiments. Only in recent years (although see next section) has it become widely recognised that properly conducted clinical trials, which follow the principle of scientific experimentation provide the only reliable basis for evaluating the efficacy and safety of new treatments.
And just what constitutes a clinical trial? There are several possible definitions, but for our purposes the term will be used for any form of planned experiment designed to assess the most appropriate treatment of future patients with a particular medical condition, where the outcome in a group of patients treated with the test treatment are compared with those observed in a similar group of patients receiving a control treatment, and patients in both groups are enrolled, treated and followed over the same time period. The groups may be established through randomisation or some other method of assignment. The outcome measure may be the result of...
