Clinical trials are investigations involving human subjects that test prospective new methods of treatment for diseases, and which involve a simultaneous comparison group, or groups, that are either untreated, placebo-treated or treated using an alternative therapy. If they demonstrate a sufficient benefit in treating the disease under investigation [usually by showing a statistically significant difference in achieving the primary endpoint, stated in the initial protocol, by comparison with the control group(s)], and if there is an acceptable minimum of adverse effects, then a clinical trial can change the standards of medical therapy. However, clinical trials can also have negative outcomes. Results of a clinical trial can show no statistically significant benefit of a new therapy over the previous standard or even a statistically significant worsening. Or, and this may only be apparent after a very large number of subjects have been exposed to the therapy, the new therapy may produce serious adverse effects in a small number of subjects, insufficient to halt its prescription for specifically indicated conditions, but sufficient to place substantial caution on its more indiscriminate use. It is evident that investigators will want the positive results of their clinical trials to be widely announced. However, past experience has shown that sponsors of clinical trials, whether they are corporations, other institutions, or individual investigators, may not wish to make public the negative or harmful results of their clinical trials.
7 8 9 It is because biomedical investigators and clinicians, as well as the public, should have a right to know both the positive and negative results of clinical trials, that registration of clinical trials before they begin recruiting subjects should be required. Such registration ensures that all clinical trials that are being conducted are in the public domain, although it does not guarantee that sponsors will publish their results in a publicly available site, or that published results are complete and accurate. However, public knowledge that a trial is being conducted should engender interest in its eventual results. Thus, at the least, it will be much more difficult for results of unsuccessful trials, or of trials with harmful results, to be hidden.