Received: 28 December 2019
Accepted: 24 July 2020
First Online: 15 August 2020
Ethics approval and consent to participate
: The research plan for this study was approved by the World Rugby Institutional Ethics committee (REF 19007). The study was conducted in accordance with the Declaration of Helsinki. Players had provided written informed consent for all data gathered as part of the World Rugby Concussion management programme to be used for research in a de-identified manner.
: Not applicable.
: Three of the authors (RT, EF, MH) are full-time and part-time employed by World Rugby in roles of research and medicine. GF has served as an independent advisor on a working group on concussion administered by World Rugby, for which expenses are covered. JB declares no competing interests.