Evidence-based toxicology: strait is the gate, but the road is worth taking.

The concept of evidence-based toxicology (EBT) was proposed in 2006, but progress since that time has been impeded by differing definitions and goals. This paper describes the parallels and discontinuities between the approach and methods of evidence-based medicine and health care and those proposed for toxicology. The critical element of an evidence-based approach for either discipline is the adoption of unbiased, transparent methodologies during the collection, appraisal, and pooling of evidence. This approach, implemented during the conduct of a systematic review, allows evaluation of the breadth and quality of available evidence. At present, systematic reviews are rarely done in toxicology by regulatory agencies, international organizations, or academic scientists. Adopting an EBT approach will necessitate significant changes in practice as well as attention to distinctive characteristics of toxicological studies, notably their emphasis on identifying harms and their reliance on experimental animal studies. An evidence-based approach does not obviate the role of judgment and values in decision making; its goal is to ensure provision of all available information in a transparent and unbiased manner.