Amsterdam 2022 process: A summary of the methodology for the Amsterdam International Consensus on Concussion in Sport.

The purpose of this paper is to summarise the consensus methodology that was used to inform the International Consensus Statement on Concussion in Sport (Amsterdam 2022). Building on a Delphi process to inform the questions and outcomes from the 5th International Conference on Concussion in Sport, the Scientific Committee identified key questions, the answers to which would help encapsulate the current science in sport-related concussion and help guide clinical practice. Over 3½ years, delayed by 2 years due to the pandemic, author groups conducted systematic reviews on each selected topic. The 6th International Conference on Concussion in Sport was held in Amsterdam (27-30 October 2022) and consisted of 2 days of systematic review presentations, panel discussions, question and answer engagement with the 600 attendees, and abstract presentations. This was followed by a closed third day of consensus deliberations by an expert panel of 29 with observers in attendance. The fourth day, also closed, was dedicated to a workshop to discuss and refine the sports concussion tools (Concussion Recognition Tool 6 (CRT6), Sport Concussion Assessment Tool 6 (SCAT6), Child SCAT6, Sport Concussion Office Assessment Tool 6 (SCOAT6) and Child SCOAT6). We include a summary of recommendations for methodological improvements for future research that grew out of the systematic reviews.

Consensus statement on concussion in sport: the 6th International Conference on Concussion in Sport-Amsterdam, October 2022.

For over two decades, the Concussion in Sport Group has held meetings and developed five international statements on concussion in sport. This 6th statement summarises the processes and outcomes of the 6th International Conference on Concussion in Sport held in Amsterdam on 27-30 October 2022 and should be read in conjunction with the (1) methodology paper that outlines the consensus process in detail and (2) 10 systematic reviews that informed the conference outcomes. Over 3½ years, author groups conducted systematic reviews of predetermined priority topics relevant to concussion in sport. The format of the conference, expert panel meetings and workshops to revise or develop new clinical assessment tools, as described in the methodology paper, evolved from previous consensus meetings with several new components. Apart from this consensus statement, the conference process yielded revised tools including the Concussion Recognition Tool-6 (CRT6) and Sport Concussion Assessment Tool-6 (SCAT6, Child SCAT6), as well as a new tool, the Sport Concussion Office Assessment Tool-6 (SCOAT6, Child SCOAT6). This consensus process also integrated new features including a focus on the para athlete, the athlete's perspective, concussion-specific medical ethics and matters related to both athlete retirement and the potential long-term effects of SRC, including neurodegenerative disease. This statement summarises evidence-informed principles of concussion prevention, assessment and management, and emphasises those areas requiring more research.

Determining Sport Concussion Assessment Tool fifth Edition (SCAT5) reliable change in male professional hockey players.

OBJECTIVES: The purpose of this paper is to provide reliable change metrics and assess the test-retest psychometrics of the Sport Concussion Assessment Tool fifth Edition (SCAT5) in a multilingual sample of professional ice hockey players. METHODS: The SCAT5 was administered to National Hockey League and American Hockey League male professional ice hockey players as part of the 2018 and 2019 season medical evaluations. We extracted data from an existing clinical database of players who were administered two consecutive baseline evaluations and had no intervening concussions to assess psychometric properties (eg, test-retest reliability) and develop reliable change metrics. RESULTS: Overall, 1007 players met inclusion criteria. Players were reassessed on average 344.52 (±62.52) days following their first baseline. Test-retest reliability ranged from r=0.3 to r=0.5. Reliable change metrics for Immediate Memory varied considerably dependent on form order. Significant differences were found between English versus non-English language preference on Immediate Memory and Concentration but not Delayed Memory or the modified Balance Error Scoring System (mBESS). Reliable change indices at the 90% CI were: Symptom Severity (5), Total Symptoms (3), Immediate Memory (3-8), Concentration (2), mBESS (5) and Delayed Memory (2-4). CONCLUSIONS: Our findings highlight the importance of considering form differences and language preference when determining reliable change from baseline on the SCAT5 in male professional hockey players. The relatively modest test-retest reliability of the measures leaves room for improved psychometric properties and increased sensitivity to concussion in future iterations of the SCAT.

Characterizing Symptoms Before and Following Concussion in Professional Hockey.

OBJECTIVE: Examine SCAT5 baseline and acute symptom subscales in professional hockey players. DESIGN: Longitudinal case-control. SETTING: Preseason medical evaluations and suspected concussion evaluations. PARTICIPANTS: NHL/AHL players were given the NHL-modified SCAT5 before the 2018-2019 season (n = 1924). During the season, English-speaking players evaluated within 1 day of injury and diagnosed with concussion (n = 140) were compared with players evaluated for possible concussion, but not given a concussion diagnosis (n = 174). INDEPENDENT VARIABLES: Concussion diagnosis and demographic characteristics. MAIN OUTCOME MEASURES: Postconcussion Symptoms Scale (PCSS) items were subdivided into affective/emotional, cognitive, somatic/physical, sleep, and headache subscales. RESULTS: Cognitive (13%), somatic/physical (10%), sleep (26%), affective (18%), and headache (6%) symptoms were reported by players at baseline. Concussed players reported more acute symptoms than active controls on each of the subscales (all P's < 0.001). Players who underwent a suspected concussion evaluation were more likely to be diagnosed with concussion if they reported affective/emotional symptoms at baseline (P < 0.001). Postinjury cognitive (P < 0.001), somatic/physical (P < 0.001), and headache (P < 0.001) symptoms best differentiated concussed players and active controls. CONCLUSIONS: Player reports of increased cognitive difficulties, somatic/physical difficulties, and headache were most associated with concussion diagnosis at the acute evaluation. An abbreviated "acute" PCSS that includes only headache, cognitive, and/or physical symptoms may be useful for diagnostic purposes when evaluation time is limited. Approximately 2% of players reported significantly elevated affective/emotional symptoms at baseline and report of affective/emotional symptoms at baseline was associated with an increased likelihood of concussion diagnosis among players referred for a suspected concussion evaluation.

The Utility of the King-Devick Test in Evaluating Professional Ice Hockey Players With Suspected Concussion.

OBJECTIVE: The purpose of this study was to (1) examine the diagnostic utility of the King-Devick (KD) in professional ice hockey players and (2) determine whether the KD provides unique variance in predicting a diagnosis of concussion when given in combination with the SCAT-5. STUDY DESIGN: Cohort Study. SETTING: Primary care. PATIENTS/PARTICIPANTS: Professional ice hockey players. INDEPENDENT VARIABLES: Diagnosis versus no diagnosis of concussion. MAIN OUTCOME MEASURES: King-Devick and SCAT-5 component scores. METHODS: In part 1, players suspected of having a concussion were evaluated at baseline and acutely with the KD and either the SCAT-3 or the SCAT-5. Players evaluated and not diagnosed with concussion served as active controls. In part 2, a separate group of players suspected of having a concussion was evaluated acutely with both the KD and SCAT-5. RESULTS: In part 1 of this study, 53 concussed players declined in performance on the KD from baseline to acute evaluation, whereas the performance of 76 active controls improved significantly. In part 2 of the study, 75 players were diagnosed with concussion and compared with 80 active controls who were evaluated and not diagnosed with concussion. Concussed players revealed a decline in KD performance from baseline to acute evaluation when compared with controls. However, the KD did not account for significant unique variance in predicting a diagnosis of concussion after accounting for SCAT-5 data. CONCLUSIONS: The KD is useful in differentiating concussed and not concussed athletes acutely, but the KD does not seem to add additional diagnostic value over and above the SCAT-5.

Return to sport for North American professional sport leagues in the context of COVID-19.

COVID-19 is a respiratory illness that can spread from person to person. A range of clinical scenarios exist, from an asymptomatic disease course to SARS and death. This document describes important considerations for 5 North American professional sports leagues (Major League Baseball, Major League Soccer, National Basketball Association, National Football League and National Hockey league) assessing when and how to resume phased operations, including practices and games. Sports should prioritise and promote the health and safety of athletes, team and operational staff, and other participants, and should not unduly increase those individuals' relative health risk while contributing to economic recovery, providing entertainment for the public and leading a responsible restoration of civic life. Because elite professional sport ordinarily is conducted in a controlled environment, professional sports leagues may be able to achieve these goals. This document is focused on professional sports leagues in North America, and although many of the statements are generalisable to professional sporting settings throughout the world, other considerations may apply to sports in other countries.

Concussion Burden, Recovery, and Risk Factors in Elite Youth Ice Hockey Players.

OBJECTIVE: To examine rates of concussion and more severe concussion (time loss of greater than 10 days) in elite 13- to 17-year-old ice hockey players. METHODS: This is a prospective cohort study (Alberta, Canada). Bantam (13-14 years) and Midget (15-17 years) male and female elite (top 20% by division of play) youth ice hockey players participated in this study. Players completed a demographic and medical history questionnaire and clinical test battery at the beginning of the season. A previously validated injury surveillance system was used to document exposure hours and injury during one season of play (8 months). Players with a suspected ice hockey-related concussion were referred to the study sport medicine physicians for assessment. Time loss from hockey participation was documented on an injury report form. RESULTS: Overall, 778 elite youth ice hockey players (659 males and 119 females; aged 13-17 years) participated in this study. In total, 143 concussions were reported. The concussion incidence rate (IR) was 17.60 concussions/100 players (95% CI, 15.09-20.44). The concussion IR was 1.31 concussions/1000 player-hours (95% CI, 1.09-1.57). Time loss of greater than 10 days was reported in 74% of cases (106/143), and 20% (n = 28) had time loss of greater than 30 days. CONCLUSIONS: Concussion is a common injury in elite youth ice hockey players. In this study population, a large proportion of concussions (74%) resulted in a time loss of greater than 10 days, possibly reflecting more conservative management or longer recovery in youth athletes.

Sport Medicine Diagnostic Coding System (SMDCS) and the Orchard Sports Injury and Illness Classification System (OSIICS): revised 2020 consensus versions.

Coding in sports medicine generally uses sports-specific coding systems rather than the International Classification of Diseases (ICD), because of superior applicability to the profile of injury and illness presentations in sport. New categories for coding were agreed on in the 'International Olympic Committee (IOC) consensus statement: Methods for recording and reporting of epidemiological data on injury and illness in sports 2020.' We explain the process for determining the new categories and update both the Sport Medicine Diagnostic Coding System (SMDCS) and the Orchard Sports Injury and Illness Classification System (OSIICS) with new versions that operationalise the new consensus categories. The author group included members from an expert group attending the IOC consensus conference. The primary authors of the SMDCS (WM) and OSIICS (JO) produced new versions that were then agreed on by the remaining authors using expert consensus methodology. The SMDCS and OSIICS systems have been adjusted and confirmed through a consensus process to align with the IOC consensus statement to facilitate translation between the two systems. Problematic areas for defining body part categories included the groin and ankle regions. For illness codes, in contrast to the ICD, we elected to have a taxonomy of 'organ system/region' (eg, cardiovascular and respiratory), followed by an 'aetiology/pathology' (eg, environmental, infectious disease and allergy). Companion data files have been produced that provide translations between the coding systems. The similar structure of coding underpinning the OSIICS and SMDCS systems aligns the new versions of these systems with the IOC consensus statement and also facilitates easier translation between the two systems. These coding systems are freely available to the sport and exercise research community.

Use of the Sport Concussion Assessment Tool 5 (SCAT5) in professional hockey, part 1: cross-cultural normative data.

OBJECTIVES: This paper provides comprehensive normative data stratified by language preference and age on the components of the National Hockey League (NHL) Sport Concussion Assessment Tool 5 (SCAT5) in a multilingual sample of professional ice hockey players and compares the findings from a paper form of the NHL SCAT5 with an electronic (App) version of the tool. METHODS: A total of 1924 male NHL and American Hockey League (AHL) players (ages 17-41) were assessed during preseason medical evaluations (baseline); 1881 were assessed with the NHL SCAT5 App via tablet and 43 received the paper version of the NHL Modified SCAT5. RESULTS: No significant differences between the App and paper modes of administration emerged in a subsample of English preference players. Significant SCAT5 differences among language preference groups emerged on measures of cognitive functioning (Immediate Memory,Concentration). No language preference differences emerged on the Delayed Recall component. Using age as a continuous variable, older participants outperformed younger players on Immediate Memory, Delayed Recall and Concentration. Players wearing skates demonstrated significantly more modified Balance Error Scoring System (mBESS) total errors than barefoot players. Normative data tables for language preference groups are presented. CONCLUSIONS: Significant differences were found between English and non-English language preference groups on the components of SCAT5, which suggest that language-specific normative data, rather than aggregated normative data, are preferable when interpreting test scores. Similarly, age-specific normative data tables may provide greater precision in data interpretation. Due to clear ceiling effects on the mBESS single leg and tandem stances, players should not be tested while wearing skates.

Use of the Sport Concussion Assessment Tool 5 (SCAT5) in professional hockey, part 2: which components differentiate concussed and non-concussed players?

OBJECTIVES: To examine the utility of Sport Concussion Assessment Tool (SCAT5) subcomponents in differentiating physician diagnosed concussed players from controls. METHODS: We evaluated 1924 professional hockey players at training camp using the National Hockey League (NHL) Modified SCAT5 prior to the 2018-2019 season. Over the course of the season, 314 English-speaking players received SCAT5 evaluations within 1 day of a suspected concussive event. Of these players, 140 (45%) were subsequently diagnosed with concussion by their team physicians. RESULTS: Concussed players reported more symptoms (Concussed M=8.52, SD=4.78; Control M=3.32, SD=3.97), and recalled fewer words than Controls on both the Immediate Memory (Concussed M=19.34, SD=4.06; Control M=21.53, SD=2.94) and Delayed Recall (Concussed z=-0.91; Control z=-0.09) tasks during the acute evaluation. Concussed players also made more errors than Controls on the mBESS and were more likely to report double vision and exhibit clinician-observed balance problems than controls. There were no between-group differences on the Concentration component of the SCAT5. Stepwise regression revealed that symptom report and list learning tasks both accounted for independent variance in identifying players diagnosed with concussion. CONCLUSIONS: These findings provide support for use of the SCAT5 to assist in identifying concussed professional hockey players. When examining SCAT5 subtests, both symptom report and the 10-item word list accounted for independent variance in identifying concussion status in this sample of professional hockey players. The mBESS also differentiated Concussed players and Controls. The Concentration component of the SCAT5 did not significantly differentiate Concussed players and Controls.

International Olympic Committee consensus statement: methods for recording and reporting of epidemiological data on injury and illness in sport 2020 (including STROBE Extension for Sport Injury and Illness Surveillance (STROBE-SIIS)).

Injury and illness surveillance, and epidemiological studies, are fundamental elements of concerted efforts to protect the health of the athlete. To encourage consistency in the definitions and methodology used, and to enable data across studies to be compared, research groups have published 11 sport-specific or setting-specific consensus statements on sports injury (and, eventually, illness) epidemiology to date. Our objective was to further strengthen consistency in data collection, injury definitions and research reporting through an updated set of recommendations for sports injury and illness studies, including a new Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist extension. The IOC invited a working group of international experts to review relevant literature and provide recommendations. The procedure included an open online survey, several stages of text drafting and consultation by working groups and a 3-day consensus meeting in October 2019. This statement includes recommendations for data collection and research reporting covering key components: defining and classifying health problems; severity of health problems; capturing and reporting athlete exposure; expressing risk; burden of health problems; study population characteristics and data collection methods. Based on these, we also developed a new reporting guideline as a STROBE Extension-the STROBE Sports Injury and Illness Surveillance (STROBE-SIIS). The IOC encourages ongoing in- and out-of-competition surveillance programmes and studies to describe injury and illness trends and patterns, understand their causes and develop measures to protect the health of the athlete. Implementation of the methods outlined in this statement will advance consistency in data collection and research reporting.

Jumper's Knee: A Prospective Evaluation of Risk Factors in Volleyball Players Using a Novel Measure of Injury.

OBJECTIVES: To examine potential intrinsic risk factors that may contribute to the onset of jumper's knee in elite level-male volleyball players. DESIGN: Prospective Cohort Study. SETTING: Varsity and National team volleyball gymnasiums. PARTICIPANTS: Sixty elite adult male volleyball players from Canada. ASSESSMENT OF RISK FACTORS: Players completed a series of risk factor assessments at the commencement of their seasons, including vertical jump (cm), ankle dorsiflexion range (degrees), dynamic balance (normalized distance reached; cm), dynamic knee alignment (degrees), and landing mechanics (degrees). MAIN OUTCOME MEASURE: Self-reported knee problems, captured via short message service. RESULTS: Knee problem prevalence was 75% [95% confidence intervals (CIs): 62.2-84.6] and the incidence rate for substantial injuries over the study period was 30 injuries/100 players/season (95% CI: 19.5-43.1). No risk factor was found to significantly predict the future occurrence of developing jumper's knee. The odds ratios were close to unity (range: 0.94-1.07) with narrow confidence intervals and P > 0.05. CONCLUSIONS: A more sensitive capture of overuse knee problems did not result in the identification of distinct risk factors for the development of jumper's knee. These findings highlight a lack of available methodology to accurately assess risk factors for overuse injuries.

International consensus definitions of video signs of concussion in professional sports.

BACKGROUND: The use of video to assist professional sporting bodies with the diagnosis of sport-related concussion (SRC) has been well established; however, there has been little consistency across sporting codes with regards to which video signs should be used, and the definitions of each of these signs. AIM: The aims of this study were to develop a consensus for the video signs considered to be most useful in the identification of a possible SRC and to develop a consensus definition for each of these video signs across the sporting codes. METHODS: A brief questionnaire was used to assess which video signs were considered to be most useful in the identification of a possible concussion. Consensus was defined as >90% agreement by respondents. Existing definitions of these video signs from individual sports were collated, and individual components of the definitions were assessed and ranked. A modified Delphi approach was then used to create a consensus definition for each of the video signs. RESULTS: Respondents representing seven sporting bodies (Australian Football League, Cricket Australia, Major League Baseball, NFL, NHL, National Rugby League, World Rugby) reached consensus on eight video signs of concussion. Thirteen representatives from the seven professional sports ranked the definition components. Consolidation and refinement of the video signs and their definitions resulted in consensus definitions for six video signs of possible concussion: lying motionless, motor incoordination, impact seizure, tonic posturing, no protective action-floppy and blank/vacant look. CONCLUSIONS: These video signs and definitions have reached international consensus, are indicated for use by professional sporting bodies and will form the basis for further collaborative research.

International study of video review of concussion in professional sports.

BACKGROUND: Video review has become an important tool in professional sporting codes to help sideline identification and management of players with a potential concussion. AIM: To assess current practices related to video review of concussion in professional sports internationally, and compare protocols and diagnostic criteria used to identify and manage potential concussions. METHODS: Current concussion management guidelines from professional national and international sporting codes were reviewed. Specific criteria and definitions of video signs associated with concussion were compared between codes. Rules and regulations adopted across the codes for processes around video review were also assessed. RESULTS: Six sports with specific diagnostic criteria and definitions for signs of concussion identified on video review participated in this study (Australian football, American football, world rugby, cricket, rugby league and ice hockey). Video signs common to all sports include lying motionless/loss of responsiveness and motor incoordination. The video signs considered by the majority of sports as most predictive of a diagnosis of concussion include motor incoordination, impact seizure, tonic posturing and lying motionless. Regulatory requirements, sideline availability of video, medical expertise of video reviewers and use of spotters differ across sports and geographical boundaries. By and large, these differences reflect a pragmatic approach from each sport, with limited underlying research and development of the video review process in some instances. CONCLUSIONS: The use of video analysis in assisting medical staff with the diagnosis or identification of potential concussion is well established across different sports internationally. The diagnostic criteria used and the expertise of the video review personnel are not clearly established, and research efforts would benefit from a collaborative harmonisation across sporting codes.

Development of a risk prediction model among professional hockey players with visible signs of concussion.

BACKGROUND: Little research examines how to best identify concussed athletes. The purpose of the present study was to develop a preliminary risk decision model that uses visible signs (VS) and mechanisms of injury (MOI) to predict the likelihood of subsequent concussion diagnosis. METHODS: Coders viewed and documented VS and associated MOI for all NHL games over the course of the 2013-2014 and 2014-2015 regular seasons. After coding was completed, player concussions were identified from the NHL injury surveillance system and it was determined whether players exhibiting VS were subsequently diagnosed with concussions by club medical staff as a result of the coded event. RESULTS: Among athletes exhibiting VS, suspected loss of consciousness, motor incoordination or balance problems, being in a fight, having an initial hit from another player's shoulder and having a secondary hit on the ice were all associated with increased risk of subsequent concussion diagnosis. In contrast, having an initial hit with a stick was associated with decreased risk of subsequent concussion diagnosis. A risk prediction model using a combination of the above VS and MOI was superior to approaches that relied on individual VS and associated MOI (sensitivity=81%, specificity=72%, positive predictive value=26%). CONCLUSIONS: Combined use of VS and MOI significantly improves a clinician's ability to identify players who need to be evaluated for possible concussion. A preliminary concussion prediction log has been developed from these data. Pending prospective validation, the use of these methods may improve early concussion detection and evaluation.

Can visible signs predict concussion diagnosis in the National Hockey League?

BACKGROUND: Early identification and evaluation of concussions is critical. We examined the utility of using visible signs (VS) of concussion in predicting subsequent diagnosis of concussion in NHL players. METHODS: VS of concussion were identified through video review. Coders were trained to detect and record specific visual signs while viewing videos of NHL regular season games. 2460 games were reviewed by at least two independent coders across two seasons. The reliability, sensitivity and specificity of these VS were examined. RESULTS: VS were reliably coded with inter-rater agreement rates ranging from 73% to 98.9%. 1215 VS were identified in 861 events that occurred in 735 games. 47% of diagnosed concussions were associated with a VS but 53% of diagnosed concussions had no VS. Of the VS, only loss of consciousness, motor incoordination, and blank/vacant look had positive likelihood ratios greater than 1, indicating a positive association with concussion diagnoses. Slow to get up and clutching of the head were observed frequently but had low positive predictive values. Sensitivity decreased and specificity increased when multiple VS occurred together. CONCLUSIONS: Non-medical personnel can be trained to reliably identify events in which VS occur and to reliably identify specific VS within each of those events. VS can be useful to detect concussion early but they are not enough since more than half of physician diagnosed concussions occurred without the presence of a visual sign. The results underscore the complexity of this injury and highlight the need for comprehensive approaches to injury detection.

Implementation of the 2017 Berlin Concussion in Sport Group Consensus Statement in contact and collision sports: a joint position statement from 11 national and international sports organisations.

The 2017 Berlin Concussion in Sport Group Consensus Statement provides a global summary of best practice in concussion prevention, diagnosis and management, underpinned by systematic reviews and expert consensus. Due to their different settings and rules, individual sports need to adapt concussion guidelines according to their specific regulatory environment. At the same time, consistent application of the Berlin Consensus Statement's themes across sporting codes is likely to facilitate superior and uniform diagnosis and management, improve concussion education and highlight collaborative research opportunities. This document summarises the approaches discussed by medical representatives from the governing bodies of 10 different contact and collision sports in Dublin, Ireland in July 2017. Those sports are: American football, Australian football, basketball, cricket, equestrian sports, football/soccer, ice hockey, rugby league, rugby union and skiing. This document had been endorsed by 11 sport governing bodies/national federations at the time of being published.

The Effect of Injury Definition and Surveillance Methodology on Measures of Injury Occurrence and Burden in Elite Volleyball.

A time-loss injury definition continues to be the most widely used injury definition despite evidence that it fails to accurately capture overuse injuries. An overuse injury questionnaire, using an "all complaints" definition has been created to address the limitation of a time-loss definition. The main aim of this work was to determine the effect that injury definition and registration methodology has on the collection of knee injuries among elite level volleyball players. To reach this goal, seventy-two volleyball players were prospectively followed over 32-weeks. Time-loss injuries were captured using an individual injury report form (IIRF). Study participants completed an overuse injury questionnaire (mOIQ) via a weekly short message service (SMS). The IIRF captured 15 time-loss knee injuries in 72 study participants (20%). Based on the mOIQ, 84.7% of participants reported having a knee problem and 66.7% sustained a substantial knee problem. All IIRF knee injuries captured were also registered by the mOIQ. Agreement on the specific diagnosis occurred for 66.7% of injuries resulting in a moderate Kappa score of 0.51. In conclusion, an overuse injury questionnaire provided a greater understanding of the magnitude and burden of knee injuries in this population.

The Berlin 2016 process: a summary of methodology for the 5th International Consensus Conference on Concussion in Sport.

The purpose of this paper is to summarise the methodology for the 5th International Consensus Conference on Concussion in Sport. The 18 months of preparation included engagement of a scientific committee, an expert panel of 33 individuals in the field of concussion and a modified Delphi technique to determine the primary questions to be answered. The methodology also involved the writing of 12 systematic reviews to inform the consensus conference and submission and review of scientific abstracts. The meeting itself followed a 2-day open format, a 1-day closed expert panel meeting and two additional half day meetings to develop the Concussion Recognition Tool 5 (Pocket CRT5), Sport Concussion Assessment Tool 5 (SCAT5) and Child SCAT5.