The following situations explain how the bias against the null hypothesis is created: Abstracts are more likely to be presented at meetings if they have adverse results than if they show no increase in risk Papers are more likely to be published if they report on adverse results than if they report on results that show no increase in risk Media reports are much more likely for papers that find adverse results than for those that show no increase in risk Physicians are much more likely to cite adverse results than results that show no increase in risk in subsequent research Journal reviewers are more likely to accept articles with adverse results for publication than articles with results that show no increase in risk

Data from Koren et al.^12–16