RT Journal Article SR Electronic T1 Guidance for reporting intervention development studies in health research (GUIDED): an evidence-based consensus study JF BMJ Open JO BMJ Open FD British Medical Journal Publishing Group SP e033516 DO 10.1136/bmjopen-2019-033516 VO 10 IS 4 A1 Edward Duncan A1 Alicia O'Cathain A1 Nikki Rousseau A1 Liz Croot A1 Katie Sworn A1 Katrina M Turner A1 Lucy Yardley A1 Pat Hoddinott YR 2020 UL http://bmjopen.bmj.com/content/10/4/e033516.abstract AB Objective To improve the quality and consistency of intervention development reporting in health research.Design This was a consensus exercise consisting of two simultaneous and identical three-round e-Delphi studies (one with experts in intervention development and one with wider stakeholders including funders, journal editors and public involvement members), followed by a consensus workshop. Delphi items were systematically derived from two preceding systematic reviews and a qualitative interview study.Participants Intervention developers (n=26) and wider stakeholders (n=18) from the UK, North America and Europe participated in separate e-Delphi studies. Intervention developers (n=13) and wider stakeholders (n=13) participated in a 1-day consensus workshop.Results e-Delphi participants achieved consensus on 15 reporting items. Following feedback from the consensus meeting, the final inclusion and wording of 14 items with description and explanations for each item were agreed. Items focus on context, purpose, target population, approaches, evidence, theory, guiding principles, stakeholder contribution, changes in content or format during the development process, required changes for subgroups, continuing uncertainties, and open access publication. They form the GUIDED (GUIDance for the rEporting of intervention Development) checklist, which contains a description and explanation of each item, alongside examples of good reporting.Conclusions Consensus-based reporting guidance for intervention development in health research is now available for publishers and researchers to use. GUIDED has the potential to lead to greater transparency, and enhance quality and improve learning about intervention development research and practice.