Table 2. Characteristics of individual studies. Authors Study title Country Study population Study design Concussion knowledge assessed (Yes/No) AXIS Critical Appraisal (areas of concern) Tier Personnel Sports IDofCON IMofCON RPP PrCON CofCON Clacy et al, 2016 A knock to the system: A new sociotechnical systems approach to sport-related concussion. Australia Amateur 17 Coaches 6 Officials Rugby Original open-ended questionnaire Yes Yes No Yes No Total concerns: 6 6, 7, 9, 14, 13, 15 Mathema et al, 2016 Concussed or Not? An Assessment of Concussion Experience and Knowledge Within Elite and Semiprofessional Rugby Union. Wales Professional & Semi- professional 44 Coaches 33 Referees Rugby Original multiple-choice questionnaire Yes Yes Yes Yes Yes Total concerns: 3 7, 14 & 18 Griffin et al, 2017 Concussion knowledge and experience among Welsh amateur rugby union coaches and referees Wales Amateur 333 Coaches 283 Officials Rugby Multiple-choice questionnaire Yes Yes Yes Yes Yes Total concerns: 4 6, 7, 13, 14 King et al, 2010 First-aid concussion knowledge of rugby league team management, administrators and officials in New Zealand. New Zealand Amateur 50 Coaches 3 Officials Rugby Open-ended & multiple-choice questionnaire Yes Yes Yes Yes Yes Total concerns: 7 3, 6, 7, 13, 14, 18, 19 Hunt et al, 2018 Knowledge, Attitudes and Concussion Information Sources Among First Nations in Ontario. Canada High school 64 Coaches + Officials Hockey Multiple-choice questionnaire Yes No Yes No No Total concerns: 4 6, 7, 13 & 14 Niederer et al, 2018 Return-to-play after concussion: state of knowledge, frequency of use and application barriers of guidelines among decision-makers in rugby. Germany Professional & Semi-professional 61 Coaches 109 Officials Rugby Original multiple-choice & scenario-based questionnaire No No Yes No No Total concerns: 3 6, 7, 13, 14 Kroshus, 2017 Calling Injury Timeouts for the Medical Evaluation of Concussion: Determinants of Collegiate Football Officials' Behavior. United States College 1324 Officials Hockey Original scenario-based questionnaire No Yes No No No Total concerns: 6 6, 7, 9, 13, 14 & 19 Guilmette, 2007 A survey of concussion knowledge and management among New England high school football coaches United States High school 62 Coaches American football Original true-false & Scenario-based questionnaire Yes Yes Yes No No Total concerns: 4 6, 7, 13 & 14 Faure, 2011 An Examination of Idaho High School Football Coaches' General Understanding of Concussion. United States High school 77 Coaches American football Original open-ended questionnaire and Interview (10 coaches) Yes Yes Yes No No Total concerns: 7 5, 6, 7, 9, 14, 15 & 19 O’Donoghue et al, 2009 Assessment of High School Coaches' Knowledge of Sport-Related Concussions. United States High school 126 Coaches Unspecified Original multiple-choice questionnaire Yes Yes Yes No No Total concerns: 4 6, 7, 13 & 14 Kirk et al, 2018 Concussion in University Level Sport: Knowledge and Awareness of Athletes and Coaches. Ireland College 8 Coaches Unspecified Multiple-choice questionnaire Yes Yes Yes No No Total concerns: 7 3, 4, 5, 6, 7, 13 & 14 Kroshus et al, 2016 Concussion Knowledge and Communication Behaviours of Collegiate Wrestling Coaches United States College 89 Coaches Wrestling Multiple-choice & scenario-based questionnaire Yes Yes No Yes Yes Total concerns: 6 5, 6, 7, 13, 14, 19 Fraas et al, 2014 Concussion knowledge and management practices among coaches and medical staff in Irish professional rugby teams. Ireland Professional 11 Coaches Rugby Multiple-choice questionnaire Yes Yes Yes No No Total concerns: 5 3, 5, 6, 7 & 14 Esquivel et al, 2013 Concussion Management, Education, and Return-to-Play Policies in High Schools: A Survey of Athletic Directors, Athletic Trainers, and Coaches. United States High School 119 Coaches Unspecified Original multiple-choice & open-ended questionnaire Yes Yes Yes No No Total concerns: 5 6, 7, 9, 13 & 14 Broglio et al, 2010 Concussion occurrence and knowledge in Italian football (soccer) Italy Amateur 27 Coaches Soccer Multiple-choice questionnaire Yes Yes Yes No Yes Total concerns: 4 6, 7, 14, 19 Kroshus, 2016 Content, Delivery, and Effectiveness of Concussion Education for US College Coaches United States College 1818 Coaches Unspecified Multiple-choice & scenario-based questionnaire Yes Yes Yes Yes No Total concerns: 4 6, 7, 13 & 14 Bramley et al, 2012 Do Youth Hockey Coaches Allow Players with a Known Concussion to Participate in a Game? United States High School 314 Coaches Hockey Original scenario-based questionnaire No Yes No No No Total concerns: 0 Guo, 2017 Exploring Gaps in Concussion Knowledge and Knowledge Translation Among Coaches of Youth Female Hockey. Canada Amateur 130 Coaches Hockey Multiple-choice questionnaire Yes Yes No Yes No Total concerns: 4 6, 7, 13 & 14 Chrisman et al, 2014 Implementation of concussion legislation and extent of concussion education for athletes, parents, and coaches in Washington State. United States High School 270 Coaches American football & soccer Original multiple-choice questionnaire Yes Yes Yes No No Total concerns: 5 6, 7, 9, 13 & 14 White et al, 2013 Knowledge about sports-related concussion: is the message getting through to coaches and trainers? Australia Amateur 519 Coaches Unspecified Multiple-choice questionnaire Yes Yes Yes Yes Yes Total concerns: 5 6, 9, 7, 13 & 14 Naftel et al, 2014 Knowledge and management of sports concussions among coaches and certified athletic trainers in Alabama. United States High school 402 Coaches Unspecified Original multiple-choice questionnaire Yes No Yes No No Total concerns: 5 6, 7, 9, 13 & 14 Saunders et al, 2012 Knowledge of Coaching Education Students Regarding Sport-Related Concussions. United States Mixed 150 Coaches Unspecified Multiple-choice questionnaire Yes Yes Yes No No Total concerns: 6 6, 7, 9, 13, 14, 15, 19 Shroyer, 2016 Knowledge of Concussions by High School Coaches in a Rural Environment. United States High school 52 coaches Unspecified Multiple-choice questionnaire Yes No Yes No No Total concerns: 7 6, 7, 10, 11, 13, 14, 19 Hossler, 2013 New Jersey Coaches' Knowledge in Recognizing and Managing Concussion United States High school 537 Coaches Unspecified Multiple-choice & scenario-based questionnaire Yes Yes No No Yes Total concerns: 6 6, 7, 9, 13, 14 & 15 Glang, 2010 Online training in sports concussion for youth sports coaches United States Below high school 75 Coaches Unspecified Multiple-choice questionnaire Yes No No No No Total concerns: 4 6, 7, 13, 14 Valovich McLeod, 2007 Sport-related concussion misunderstanding among youth coaches. United States Below high school 156 Coaches Unspecified Original multiple-choice & scenario-based questionnaire Yes Yes No No No Total concerns: 5 6, 7, 13, 14 & 18 Mrazik, 2011 Sport-related concussions: knowledge translation among minor hockey coaches. Canada Mixed Coaches Hockey Original multiple-choice & scenario-based questionnaire Yes Yes Yes Yes No Total concerns: 5 6, 7, 9, 13 & 14 IDofCON : Identification of concussion; IMofCON : Initial management of concussion; RPP : Return-to-play principles; PrCON : Prevention of Concussion; CofCON Consequences of concussion.