Grading the Evidence: The Core of EBD

The evidence pyramid ranks the reliability of evidence from low (bottom tier of pyramid) to high (RCT = randomized controlled trial). The 3 highest level of evidence consist of systematic experiments and became routine in the second half of the 20th century. With an inverted evidence pyramid, the reliability of evidence is ranked in a reverse order and biological plausibility is considered most reliable and RCTs are “used” to prove biological plausibility.