Competing interests: CH participated in the ICIJ investigation but received no payments. CH is Director of the Centre for Evidence-Based Medicine at the University of Oxford, and Editor in Chief of BMJ Evidence-Based Medicine. He has received expenses and fees for his media work. He holds grant funding from the NIHR, the NIHR School of Primary Care Research, The NIHR Oxford BRC and WHO. He has also received income from the publication of a series of toolkit books. CEBM jointly runs the EvidenceLive Conference with the BMJ and the Overdiagnosis Conference with some international partners which are based on a non-profit model.