Competing interests: We have read and understood BMJ policy on declaration of interests and declare the following: CH has been an expert witness in a mesh medical device legal case, but took no payment. He has received financial remuneration from an asbestos legal case. He has received expenses in the past from the FDA to attend a working group on device regulation. JKA has published papers and edited textbooks on adverse drug reactions; he has also acted as an expert witness in cases related to adverse drug reactions. BG reports personal fees from intermittent additional personal income from speaking and writing for lay audiences on problems in science and medicine including regulatory shortcomings. CH receives funding from the National Institute for Health Research (NIHR) School of Primary Care. BG receives funding from the Laura and John Arnold Foundation.