Читать книгу Evidence in Medicine - Iain K. Crombie - Страница 26

A basic principle of pharmacology is that ‘all drugs have beneficial and harmful effects’ [34], with the value of the drug depending on the benefit: harm ratio. Establishing where the balance lies can be difficult because the harms are frequently under‐reported in published clinical trials [35, 36]. One study found that 43% of adverse events recorded in trial registries were not reported in the published study [37]. A review of such studies concluded that, on average, some 64% of harms were not reported [38]. The benefit: harm ratio may often be biased because of the under‐reporting of harms [39].