Abstract
Footnotes IC is indebted to Richard Ashcroft, Angela Coulter, Glyn Elwyn, Paul Glasziou, Jos Kleijnen, Alessandro Liberati, Andy Oxman, Dave Sackett, Trevor Sheldon, Ray Tallis, Hazel Thornton, Jan Vandenbroucke, John Williams, and Kent Woods for helpful comments on an earlier draft of this article. Funding IC receives a part time salary funded by the Medical Research Council and the Department of Health. Competing interests None declared.