Evidence-based paradigms and opinions in clinical management and cancer research.

Clinical management involves values, the recognition of a patient's unique circumstances, and information. Given strong biases in the way we all process experience, clinical decision making must acknowledge the results of formal research. Evidence-based clinical management requires that we take account of the whole body of available evidence, not a potentially biased "biopsy" of it. Systematic literature review is therefore a central element. Such an approach is time consuming and requires skills in literature search and data evaluation, which physicians frequently have not been taught. Computing and library facilities are an important aid, as is the development of evidence-based resources such as the Cochrane Library Collection. Practice guidelines can prove useful and acceptable to clinicians if they are both evidence- and practice-based. The largest single obstacle to evidence-based clinical management is the bias against the reporting of studies with negative findings. This can be overcome by compulsory trial registration.