RESUMEN
INTRODUCTION: There is growing evidence on the ethical challenges raised by cluster randomized trials. This specificity is not reflected in the legal texts regulating research, which creates difficulties for researchers implementing these experimental designs. The Ottawa Statement (Weijer et al. 2012) aims to provide detailed guidance on the ethical design, conduct and assessment of cluster trials. More broadly aims to help research stakeholders and decision-makers to make informed ethical decisions regarding the particularity of these experimental designs. It seems that this international statement, written in English, is not sufficiently accessible to all of the French professionals involved in health research. The aim of this article is to provide these professionals with a contextualized and illustrated French translation of the "Ottawa statement". METHOD: . The "complex design" working group of the RECaP network (Research in Clinical Epidemiology and Public Health), carried out this work. A first version was discussed by the authors in several meetings. It was completed by contextual explanations and examples of French studies currently conducted by the authors. The final version was obtained by consensus and validated by the group. RESULTS: . This work reports 15 recommendations grouped into 7 key questions: How to justify cluster design? How to submit an article to an ethics committee? How to identify research participants? How and when to obtain informed consent? Who are the gatekeepers? How to assess benefits and harm? How to protect vulnerable participants? Each of these recommendations is specific to cluster trials. The recommendations are explained and detailed through concrete examples. CONCLUSION: Without interfering with current French laws, this work provides a framework for the organization, conduct and ethical assessment of cluster randomized trials in France. In the present-day context, it is essential that all concerned groups can base their decisions on recommendations in line with the elementary principles of health research ethics.