There is a growing public awareness that selective publishing biases lead to a distorted and overly optimistic view of the effectiveness of many medications and obscure evidence regarding harmful side effects. A substantial proportion clinical trials evaluating the effectiveness of new medications are funded by pharmaceutical companies. A 2010 study conducted by researchers from both Harvard and Toronto reviewed 500 clinical trials evaluating the effectiveness of five major classes of drugs: antidepressants, ulcer mediation, and so on. They found that 85% of the studies funded by pharmaceutical companies were positive, but only 50% of government funded trials were positive.
In a New York Times article titled Breaking the Drug Seal, journalist Katie Thomas reports on recent initiatives by investigators to find ways of reducing this publication bias.