Treatments should be based on reviews of the best available evidence. However, there are different views about the types of evidence that may be included. Evidence-based medicine (EBM) has its own clear hierarchy with systematic reviews of randomized controlled trials (RCTs) at the top level and expert and user opinion at the lowest level of evidence. Other paradigms, such as qualitative approaches, are difficult to place in such a hierarchy.

This article examines some of the assumptions behind evidence-based practice, particularly when applied to complex “real life” clinical situations. A case example is used to demonstrate some of the complexity of applying evidence to practice. A complementary paradigm of practice-based evidence is described.