Daniele Fanelli1,2, John P A Ioannidis1,3,4, Steven Goodman1,5,6. 1. Meta-Research Innovation Center at Stanford (METRICS), Stanford, CA, USA. 2. Department of Methodology, London School of Economics and Political Science, London, UK. 3. Departments of Medicine of Health Research and Policy, and of Biomedical Data Science, Stanford University School of Medicine, Stanford, CA, USA. 4. Department of Statistics, Stanford University School of Humanities and Sciences, Stanford, CA, USA. 5. Division of Epidemiology, Department of Health Research and Policy, Stanford University School of Medicine, Stanford, CA, USA. 6. Division of Primary Care and Population Health, Department of Medicine, Stanford University School of Medicine, Stanford, CA, USA.