Levels of evidence

The concept of evidence based medicine (EBM) probably began with Professor Archie Cochrane, a British medical researcher in the 1970s who wrote in 1979 “It is surely a great criticism of our profession that we have not organized a critical summary, by specialty or subspecialty, adapted periodically, of all relevant randomized controlled trials” [1]. Subsequently, scientists such as David Eddy of North Carolina and Gordon Guyett and David Sackett of Hamilton advanced Cochranes’ work by promoting randomized trials and coined the term ‘evidence-based medicine”.