The ICMJE uses the World Health Organization (WHO) definition of a clinical trial, which is “any research study that prospectively assigns human participants or groups of humans to one or more health-related interventions to evaluate the effects on health outcomes”. This definition includes phase I to IV trials. The ICMJE defines health-related interventions as “any intervention used to modify a biomedical or health-related outcome” and health-related outcomes as “any biomedical or health-related measures obtained in patients or participants”. Authors who are unsure whether their trial needs registering should consult the ICMJE FAQs for further information.
Suitable publicly available registries are those listed on the ICMJE website as well as any of the primary registries that participate in the WHO International Clinical Trials Registry Platform, including the ISRCTN registry, which is administered and published by Biomed Central.
The trial registration number (TRN) and date of registration should be included as the last line of the manuscript abstract.
For clinical trials that have not been registered prospectively, ISCI encourages retrospective registration to ensure the complete publication of all results. Further information on retrospective registration is available from the AllTrials campaign, the Public Accounts Committee and the Department of Health. Many ISCI journals consider manuscripts describing retrospectively registered studies. The TRN and date of registration should be included as the last line of the manuscript abstract.
Registration of systematic reviews
ISCI journals support the prospective registration of systematic reviews and encourages authors to register their systematic reviews in a suitable registry (such as PROSPERO). Authors who have registered their systematic review should include the registration number as the last line of the manuscript abstract.