TY - JOUR T1 - Refining the E in EBM JF - BMJ Evidence-Based Medicine JO - BMJ EBM SP - 189 LP - 190 DO - 10.1136/bmjebm-2020-111348 VL - 25 IS - 6 AU - Tom Jefferson Y1 - 2020/12/01 UR - http://ebm.bmj.com/content/25/6/189.abstract N2 - This is the second in a series of notes addressing the need to change our evidence sources for assessing the effects of pharmaceuticals and biologics because of the danger of unrecognised reporting bias. In this note I shall discuss the possibility of using a shorter way of redefining the E than using clinical study reports.In the first note—‘Redefining the ‘E’ in EBM’— I made the point that trial publications (if they exist) are the tip of the data iceberg.1 The ‘iceberg’ is made up of a complex and massive reality of thousands of pages of clinical study reports, manuals, forms and slides of meetings invisible below the waterline. The submerged part is likely to represent anything between 1 and 8000 pages of published material.2 Even more importantly, the submerged material has the potential to change the conclusions of systematic reviews. To prove this point we have presented a list of references in our first editorial1 and at the Restoring Invisible and … ER -