Footnotes

• Twitter @osmanhahmed, @HowellDR, @Kat_Schneider7, @SammoWalton, @jonpatricios

• Contributors RJE served as the primary author and responsible for all aspects of the project, including initial preparation, coordination, review, editing and final preparation of the manuscript and CRT6 tool. All co-authors contributed to the development and critical review of the manuscript and CRT6 tool, and approved the final version of the manuscript and tool.

• Competing interests OHA reports employment from University Hospitals Dorset NHS Foundation Trust (England) as a Senior Physiotherapist, and paid employment from the Football Association (England) as Para Football Physiotherapy Lead, Para Football Classification Lead, and Physiotherapist to the England Cerebral Palsy Football squad. Unpaid roles/voluntary roles: University of Portsmouth (England) as Visiting Senior Lecturer; Para Football Foundation as Medical Unit Co-Lead; the International Federation of Cerebral Palsy Football as Medical and Sports Science Director; the International Blind Sports Association as a Medical Committee member; British Journal of Sports Medicine Medicine as Associate Editor; BMJ Open Sports & Exercise Medicine as Associate Editor; World Rugby as Institutional Ethics Committee external member; the Concussion in Para Sport Group as co-chair; and the Concussion in Sport Group as board member. CMB reports affiliations with the Cleveland Browns (National Football League) and Cleveland Monsters (American Hockey League), a board position in the Sports Neuropsychology Society, and occasional expert consulting fees. JMB reports being a part-time employee of the NHL. JMB’s institution has received funding from Genzyme, and EyeGuide supporting his work, and he has served as a paid consultant to Med-IQ and Sporting KC. JSB reports receiving methods author funding for this review and Alexander Graham Bell Canada Graduate Scholarships-Doctoral Program. GAD is a member of the Scientific Committee of the 6th International ConsensusConference on Concussion in Sport; an honorary member of the AFL Concussion Scientific Committee; Section Editor, Sport and Rehabilitation, NEUROSURGERY; and has attended meetings organised by sporting organisations including the NFL, NRL, IIHF, IOC and FIFA; however has not received any payment, research funding, or other monies from these groups other than for travel costs. RJE is a paid consultant for the National Hockey League and co-chair of the National Hockey League /National Hockey League Players' Association Concussion Subcommittee, Major League Soccer’s Concussion Committee and the US Soccer Federation, provides testimony in matters related to mTBI and reports a grant from Boston Children’s Hospital (sub-award from the National Football League) and travel support for the CIS conference and other professional conferences, an unpaid board member of CISG and leadership roles (unpaid) in professional organizations. GG Reports grant funding from CDC TEAM and OnTRACK grants, NIMH APNA grant, royalties from PAR, consulting fees from NFL Baltimore Ravens, Zogenix International, and Global Pharma Consultancy, and travel support for professional meetings. He is a member of USA Football Medical Advisory Panel. DH reports research support from the Eunice Kennedy Shriver National Institute of Child Health & Human Development, the National Institute of Neurological Disorders And Stroke, the National Institute of Arthritis and Musculoskeletal and Skin Diseases, 59th Medical Wing Department of the Air Force, MINDSOURCE Brain Injury Network, the Tai Foundation, and the Colorado Clinical and Translational Sciences Institute (UL1 TR002535‐05) and he serves on the Scientific/Medical Advisory Board of Synaptek, LLC. GF is a member of the BJSM editorial board. CM reports no financial COI. She holds leadership positions with several organizations American College of Sports Medicine, American Medical Society for Sports Medicine, Pediatric Research in Sports Medicine, Council on Sports Medicine and Fitness, American Academy of Pediatrics, Untold Foundation, Pink Concussions, Headway Foundation, and the editorial boards of Journal of Adolescent Health, Frontiers in Neuroergonomics, Exercise, Sport, and Movement. JP reports travel support for the CIS conference and other professional meetings, consulting fees and grant funding from World Rugby, and an unpaid board member of CISG and EyeGuide. He is a member of the BJSM editorial board. KJS has received grant funding from the Canadian Institutes of Health Research (CIHR), NFL Scientific Advisory Board, International Olympic Committee Medical and Scientific Research Fund, World Rugby, Mitacs Accelerate, University of Calgary, with funds paid to her institution and not to her personally. She is an Associate Editor of BJSM (unpaid), Independent consultant to World Rugby and has received travel and accommodation support for meetings where she has presented. She coordinated the writing of the systematic reviews that informed Amsterdam International Consensus on Concussion in Sport, for which she has received an educational grant to assist with the administrative costs associated with the writing of the reviews (with funds paid to her institution). She is a member of the AFL Concussion Scientific Committee (unpaid position), Brain Canada (unpaid positions) and Board member of the Concussion in Sport Group (CISG)(unpaid). She works as a physiotherapy consultant and treats athletes of all levels of sport from grass roots to professional. JVI reports CIHR Postdoctoral Fellowship Award, UOMBRI Grant, travel stipend from CTRC and Founder of R2P™ Concussion Management. JPar reports no disclosures. SRW reports honoraria and travel support for professional meetings and leadership positions in World Federation of Athletic Training and Therapy and Outcomes, International Traumatic Brain Injury Research Initiative. RZ reports competitively-funded research grants from Canadian Institutes of Health Research (CIHR), Ontario Neurotrauma Foundation (ONF), Physician Services Incorporated (PSI) Foundation, CHEO Foundation, Ontario Brain Institute (OBI), Health Canada, Public Health Agency of Canada (PHAC), Ontario SPOR Support Unit (OSSU), Ontario Ministry of Health, and the National Football League (NFL) Scientific Advisory Board. He is Clinical Research Chair in Pediatric Concussion from University of Ottawa, and a volunteer board member the North American Brain Injury Society (NABIS). Co-founder, Scientific Director and a minority shareholder in 360 Concussion Care, an interdisciplinary concussion clinic.

• Provenance and peer review Not commissioned; internally peer reviewed.