Drug treatments constitute a substantial portion of all health-care interventions. Despite their notable benefits, however, drug treatments are beyond the reach of sizable population groups and in someparts of the world there is little access to safe and effective medications even though new drugs are constantly being developed.
The effectiveness and safety of newly developed drugs are often viewed too optimistically. According to a Cochrane systematic review published recently, new drugs are seldom found to be substantially better than existing treatments. However, because of lack of full and transparent access to the protocols of many clinical trials, compounded by publication bias and selective reporting of their findings, the true effectiveness of many drugs remains unknown. It is a fact that the results of trials are more likely to be published if the findings are favourable than if they are not. In addition, some measured outcomes are never reported, which generally results in an overestimation of effectiveness and an underestimation of harmful effects.