The statement of the International Committee of Medical Journal Editors (ICMJE)1,2 that clinical trial registration is a requirement for publication of trial results in their journals has captured the attention of researchers around the world. The editors noted that ClinicalTrials.gov (http://clinicaltrials.gov), an international trials registry developed and maintained by the US National Institutes of Health, met their criteria for an acceptable registry.2 We are writing to address misunderstandings about the current policies and procedures of this registry.
A memorandum sent to Canadian health researchers by Mark Bisby, Vice-President of the Canadian Institutes of Health Research (CIHR), on Sept.1, 2005, claimed that ClinicalTrials.gov does not provide unique trial identifiers and does not register nondrug trials.3 Both of these statements are incorrect. ClinicalTrials.gov encourages and accepts the registration of any observational or interventional studies with health or biomedical outcomes in humans; trials of any intervention, such as drugs, devices and behavioural interventions; and trials conducted anywhere in the world by any sponsor. In addition to providing a unique identifier for each registered study, ClinicalTrials.gov offers quality control for trial data, a Web-based data entry and update tool (http://prsinfo.clinicaltrials.gov/) and a sophisticated search function.