Partnering With Patients, Caregivers, and Clinicians to Determine Research Priorities for Concussion.

Importance: Identifying research priorities of patients with concussion, their caregivers, and their clinicians is important to ensure future concussion research reflects the needs of those who will benefit from the research. Objective: To prioritize concussion research questions from the perspectives of patients, caregivers, and clinicians. Design, Setting, and Participants: This cross-sectional survey study used the standardized James Lind Alliance priority-setting partnership methods (2 online cross-sectional surveys and 1 virtual consensus workshop using modified Delphi and nominal group techniques). Data were collected between October 1, 2020, and May 26, 2022, from people with lived concussion experience (patients and caregivers) and clinicians who treat concussion throughout Canada. Exposures: The first survey collected unanswered questions about concussion that were compiled into summary questions and checked against research evidence to ensure they were unanswered. A second priority-setting survey generated a short list of questions, and 24 participants attended a final priority-setting workshop to decide on the top 10 research questions. Main Outcomes and Measures: Top 10 concussion research questions. Results: The first survey had 249 respondents (159 [64%] who identified as female; mean [SD] age, 45.1 [16.3] years), including 145 with lived experience and 104 clinicians. A total of 1761 concussion research questions and comments were collected and 1515 (86%) were considered in scope. These were combined into 88 summary questions, of which 5 were considered answered following evidence review, 14 were further combined to form new summary questions, and 10 were removed for being submitted by only 1 or 2 respondents. The 59 unanswered questions were circulated in a second survey, which had 989 respondents (764 [77%] who identified as female; mean [SD] age, 43.0 [4.2] years), including 654 people who identified as having lived experience and 327 who identified as clinicians (excluding 8 who did not record type of participant). This resulted in 17 questions short-listed for the final workshop. The top 10 concussion research questions were decided by consensus at the workshop. The main research question themes focused on early and accurate concussion diagnosis, effective symptom management, and prediction of poor outcomes. Conclusions and Relevance: This priority-setting partnership identified the top 10 patient-oriented research questions in concussion. These questions can be used to provide direction to the concussion research community and help prioritize funding for research that matters most to patients living with concussion and those who care for them.

Prevention strategies and modifiable risk factors for sport-related concussions and head impacts: a systematic review and meta-analysis.

OBJECTIVES: To evaluate prevention strategies, their unintended consequences and modifiable risk factors for sport-related concussion (SRC) and/or head impact risk. DESIGN: This systematic review and meta-analysis was registered on PROSPERO (CRD42019152982) and conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. DATA SOURCES: Eight databases (MEDLINE, CINAHL, APA PsycINFO, Cochrane (Systematic Review and Controlled Trails Registry), SPORTDiscus, EMBASE, ERIC0 were searched in October 2019 and updated in March 2022, and references searched from any identified systematic review. ELIGIBILITY CRITERIA: Study inclusion criteria were as follows: (1) original data human research studies, (2) investigated SRC or head impacts, (3) evaluated an SRC prevention intervention, unintended consequence or modifiable risk factor, (4) participants competing in any sport, (5) analytic study design, (6) systematic reviews and meta-analyses were included to identify original data manuscripts in reference search and (7) peer-reviewed. Exclusion criteria were as follows: (1) review articles, pre-experimental, ecological, case series or case studies and (2) not written in English. RESULTS: In total, 220 studies were eligible for inclusion and 192 studies were included in the results based on methodological criteria as assessed through the Scottish Intercollegiate Guidelines Network high ('++') or acceptable ('+') quality. Evidence was available examining protective gear (eg, helmets, headgear, mouthguards) (n=39), policy and rule changes (n=38), training strategies (n=34), SRC management strategies (n=12), unintended consequences (n=5) and modifiable risk factors (n=64). Meta-analyses demonstrated a protective effect of mouthguards in collision sports (incidence rate ratio, IRR 0.74; 95% CI 0.64 to 0.89). Policy disallowing bodychecking in child and adolescent ice hockey was associated with a 58% lower concussion rate compared with bodychecking leagues (IRR 0.42; 95% CI 0.33 to 0.53), and evidence supports no unintended injury consequences of policy disallowing bodychecking. In American football, strategies limiting contact in practices were associated with a 64% lower practice-related concussion rate (IRR 0.36; 95% CI 0.16 to 0.80). Some evidence also supports up to 60% lower concussion rates with implementation of a neuromuscular training warm-up programme in rugby. More research examining potentially modifiable risk factors (eg, neck strength, optimal tackle technique) are needed to inform concussion prevention strategies. CONCLUSIONS: Policy and rule modifications, personal protective equipment, and neuromuscular training strategies may help to prevent SRC. PROSPERO REGISTRATION NUMBER: CRD42019152982.

Physical Contact and Suspected Injury Rates in Female versus Male Youth Ice Hockey: A Video-Analysis Study.

OBJECTIVE: Canada's national winter sport of ice hockey has high youth participation; however, research surrounding female ice hockey is limited and the injury burden remains high. This study compared rates of head contact (HC), body checking (BC; high-intensity player-to-player contact), and suspected concussion between female and male youth ice hockey. DESIGN: Cross-sectional. SETTING: Game video-recordings captured in Calgary, Canada. PARTICIPANTS: Ten female (BC prohibited) and 10 male (BC permitted) U15 elite AA (13-14-year-old) game video-recordings collected in the 2021 to 22 seasons and 2020 to 21, respectively. ASSESSMENT OF RISK FACTORS: An analysis of player-to-player physical contact and injury mechanisms using video-analysis. MAIN OUTCOME MEASURES: Videos were analyzed in Dartfish video-analysis software and all physical contacts were coded based on validated criteria, including HCs (direct [HC1], indirect [HC2]), BC (levels 4-5 on a 5-point intensity scale), and video-identified suspected concussions. Univariate Poisson regression clustering by team-game offset by game-length (minutes) were used to estimate incidence rates and incidence rate ratios (IRR, 95% confidence intervals). RESULTS: The female game had a 13% lower rate of total physical contacts (IRR = 0.87, 0.79-0.96) and 70% lower rate of BC (IRR = 0.30, 0.23-0.39). There were however no differences in the rates of direct HC (IRR = 1.04, 0.77-1.42) or suspected concussion (IRR = 0.42, 0.12-1.42) between the cohorts. Although prohibited in the female game, only 5.4% of HC1s and 18.6% of BC resulted in a penalty. CONCLUSIONS: The rates of HC1s and suspected concussions were similar across youth ice hockey. BC rates were lower in the female game, yet still prevalent despite being prohibited.

Protective equipment in youth ice hockey: are mouthguards and helmet age relevant to concussion risk?

OBJECTIVES: To compare the incidence rates and odds of concussion between youth ice hockey players based on mouthguard use and helmet age. MATERIALS AND METHODS: Within a 5-year longitudinal cohort (2013/2014 to 2017/2018) of male and female ice hockey players (ages 11-18; n=3330 players) in Alberta (Canada), we analysed the relationship of equipment and concussion in both a prospective cohort and nested case (concussion) control (acute musculoskeletal injury) approach. The prospective cohort included baseline assessments documenting reported mouthguard use (yes/sometimes, no use), helmet age (newer/<2 years old, older/≥2 years old) and important covariables (weight, level of play, position of play, concussion history, body checking policy), with weekly player participation throughout the season. The nested case-control component used injury reports to document equipment (mouthguard use, helmet age) and other information (eg, mechanism and type of injury) for the injury event. Multivariable mixed effects negative binomial regression (prospective cohort, incidence rate ratios (IRRs)) and multivariable mixed effects logistic regression (nested case-control, odds ratios (OR)) examined the association between equipment and concussion. RESULTS: Players who reported wearing a mouthguard had a 28% lower concussion rate (IRR=0.72, 95% CI 0.56 to 0.93) and 57% lower odds of concussion (OR=0.43, 95% CI 0.27 to 0.70) compared with non-wearers. There were no associations in the concussion rate (IRR=0.94, 95% CI 0.75 to 1.15) and odds (OR=1.16, 95% CI 0.73 to 1.86) between newer and older helmets. CONCLUSIONS: Wearing a mouthguard was associated with a lower concussion rate and odds. Policy mandating use should be considered in youth ice hockey. More research is needed to identify other helmet characteristics (eg, quality, fit) that could lower concussion risk.

Can Referees Assess Head Contact Penalties Correctly in Canadian Youth Ice Hockey? A Video Analysis Study.

OBJECTIVE: To help address the high concussion burden in Canadian youth ice hockey, our primary objective was to examine the concurrent validity of youth ice hockey referees' ability to assess head contacts (HCs) and associated penalties using video analysis methods after implementation of the "zero tolerance for HC" policy by Hockey Canada. STUDY DESIGN: Cross-sectional study. PARTICIPANTS: Certified Level II-III referees in Alberta, Canada. INTERVENTION: A secured online survey with 60 videos (10 to 15 seconds) containing a player-to-player physical contact with or without a HC from elite U15 (ages 13 to 14) youth ice hockey games. OUTCOME MEASURES: Survey questions were completed by all referees for each video, including (1). 'Did you see a player-to-player contact?', (2). 'Should a penalty be assessed?', and if yes, (3). 'Which player, penalty type, and penalty intensity?' Referee assessments were compared with a consensus agreement from 2 national and member (top level) gold standard referees for concurrent validity through percent agreement and sensitivity/specificity measures. RESULTS: Complete-case analysis of 100 referees (131 recruited) showed an overall median agreement of 83.5% (sensitivity = 0.74; specificity = 0.69) with the gold standard. Agreement with the gold standard was highest for HC infractions [85.1% (sensitivity = 0.80; specificity = 0.69)], followed by HC penalty type (81.5%) and penalty intensity (53.7%). CONCLUSIONS: Concurrent validity through percent agreement was high (>80%) compared with the gold standard for identifying both HC and other infractions; however, it was moderate for penalty intensity. Although knowledge of identifying HCs and penalties in this survey was acceptable, this study suggests in-game factors (eg, game management and positioning) may be a primary limitation for HC enforcement.

Higher Rates of Head Contacts, Body Checking, and Suspected Injuries in Ringette Than Female Ice Hockey: Time to Ring in Opportunities for Prevention.

OBJECTIVE: Ringette and female ice hockey are high participation sports in Canada. Despite policies disallowing body checking, both sports have high injury and concussion rates. This study aimed to compare physical contact (PC), head contact (HC), and suspected injury and concussion incidence rates (IRs) in female varsity ringette and ice hockey. DESIGN: Cross-sectional. SETTING: Canadian ice arenas. PARTICIPANTS: Eighteen Canadian female university ringette and ice hockey tournament/playoff games in the 2018-2019/2019-2020 seasons. ASSESSMENT OF RISK FACTORS: Game video-recordings were analyzed using Dartfish video-analysis software to compare both sports. MAIN OUTCOME MEASURES: Univariate Poisson regression analyses (adjusted for cluster by team, offset by game-minutes) were used to estimate PC, HC, and suspected injury IRs and incidence rate ratios (IRRs) to compare rates across sports. Proportions of body checks (level 4-5 trunk PC) and direct HC (HC 1 ) penalized were reported. RESULTS: Analyses of 36 team-games (n = 18 ringette, n = 18 hockey) revealed a 19% lower rate of PCs in ringette than ice hockey {IRR = 0.81 [95% confidence interval (CI), 0.73-0.90]}, but a 98% higher rate of body checking [IRR = 1.98 (95% CI, 1.27-3.09)] compared to ice hockey. Ringette had a 40% higher rate of all HC 1 s [IRR = 1.40 (95% CI, 1.00-1.96)] and a 3-fold higher rate of suspected injury [IRR = 3.11 (95% CI, 1.13-8.60)] than ice hockey. The proportion of penalized body checks and HC 1 s were low across sports. CONCLUSIONS: Body checking and HC 1 rates were significantly higher in ringette compared to ice hockey, despite rules disallowing both, and very few were penalized. These findings will inform future injury prevention research in ringette and female ice hockey.

Concussions and Injuries in Sledge Hockey: Grassroots to Elite Participation.

OBJECTIVE: To examine injury (including concussion) rates, location, type, mechanisms, and risk factors in sledge hockey players. DESIGN: Cross-sectional survey. SETTING: Sledge hockey players, worldwide, across all levels of play. PARTICIPANTS: Sledge hockey players (ages ≥14 years) who played in the 2019 to 2020 season were recruited through email, social media, and word of mouth communication. ASSESSMENT OF RISK FACTORS: Participant characteristics (eg, age, sex, disability) were examined as potential injury risk factors. MAIN OUTCOME MEASURES: Injury rates (IR) and incidence rate ratios (IRR) examining potential risk factors were reported based on univariate Poisson regression analyses. Injury proportions by type, location, and mechanism were described. RESULTS: Ninety-two players initiated the survey, and 77 (83.7%) provided some injury information. Forty-seven injuries included 16 concussions in 9 of 77 players (11.7%) and 31 non-concussion injuries in 20 of 77 players (26.0%) were reported. The overall IR was 13.2 injuries/1000 athlete-exposures [95% confidence interval (CI); 9.6-17.6]. The game IR (28.4 injuries/1000 game-exposures, 95% CI; 18.6-41.7) was higher than practice IR (4.4 injuries/1000 practice-exposures, 95% CI; 2.2-7.9) (IRR = 6.5, 95% CI; 3.1-14.5). The most common injury locations were the head (34.0%), wrist/hand (14.8%), and shoulder (10.6%). The most common significant injury types were concussion (36.2%) and bone fracture (8.5%). Body checking was the primary mechanism for injuries caused by contact with another player (42.1%) Age, sex, disability, and level of play were not found as injury risk factors. CONCLUSIONS: Concussions and upper extremity injuries were the most common sledge hockey injuries reported, with body checking being the most common mechanism. This research will inform development of prevention strategies in sledge hockey.

Does Increasing the Severity of Penalties Assessed in Association With the "Zero Tolerance for Head Contact" Policy Translate to a Reduction in Head Impact Rates in Youth Ice Hockey?

OBJECTIVE: The risk of concussion is high in Canadian youth ice hockey. Aiming to reduce this burden, in 2011, Hockey Canada implemented a national "zero tolerance for head contact (HC)" policy mandating the penalization of any player HC. In 2018 to 2020, Hockey Canada further amended this HC policy including stricter enforcement of severe HCs. This study aimed to compare HC rates, head impact location, and HC enforcement prepolicy, postpolicy, and after policy amendments in elite U15 Canadian youth ice hockey. DESIGN: This is a prospective cohort study. SETTING: A collection of events with the video camera located at the highest point near center ice in public ice hockey arenas in Calgary, Alberta. PARTICIPANTS: A convenience sample of 10 AA U15 games prepolicy (2008-2009), 8 games postpolicy (2013-2014), and 10 games after policy amendments (2020-2021). INDEPENDENT VARIABLES: An analysis of 3 cohort years regarding the HC-policy implementation and amendments. MAIN OUTCOME MEASURES: Using Dartfish video-analysis software, all player contacts and HCs [direct (HC1), indirect (eg, boards, ice) (HC2)] were tagged using validated criteria. Univariate Poisson regression clustering by team-game offset by game length (minutes) was used to estimate incidence rates (IR) and incidence rate ratios (IRR) between cohorts. RESULTS: With additional rule modifications, a 30% reduction in HC1s emerged (IRR 2013-2020 = 0.70, 95% CI, 0.51-0.95). Since the HC-policy implementation, HC1s decreased by 24% (IRR 2008-2020 = 0.76, 95% CI, 0.58-0.99). The proportion of HC1s penalized was similar across cohorts (P 2008-2009 = 14.4%; P 2013-2014 = 15.5%; P 2020-2021 = 16.2%). CONCLUSIONS: The HC-policy amendments have led to decreased HC1 rates. However, referee enforcement can further boost the HC-policy effectiveness. These findings can help future referee training and potential rule modifications to increase player safety nationally.

Evaluating the Effect of Policy Prohibiting Body Checking on Physical Contacts in U15 and U18 Youth Ice Hockey Leagues.

OBJECTIVE: To compare physical contacts (PCs) and head contacts (HCs) in nonelite U15 (ages 13-14) and U18 (ages 15-17) ice hockey players in body checking (BC) and non-BC leagues. DESIGN: Cohort video analysis study. SETTING: Ice hockey arenas in Calgary, Canada. PARTICIPANTS: Players from 13 BC and 13 non-BC games at the nonelite U15 and U18 levels (n = 52 total games). ASSESSMENT OF RISK FACTORS: Games were videotaped and analyzed to compare PC variables between leagues allowing and prohibiting BC. MAIN OUTCOME MEASURES: Validated methodology for PC type (trunk PC and other types of PC with limb/stick/head), intensity (low and high intensity), and HC. Incidence rate ratios (IRRs) were estimated using Poisson regression (controlling for cluster by team game and offset by player minutes) to compare the incidence of PCs in BC and non-BC games. RESULTS: The rate of trunk PCs was lower in the non-BC leagues for both U15 (IRR = 0.50, 99% confidence interval [CI]: 0.43-0.58) and U18 (IRR = 0.56, 99% CI: 0.46-0.67) players. This was most significant for BC contacts (U15: IRR = 0.18, 99% CI: 0.11-0.29; U18: IRR = 0.16, 99% CI: 0.08-0.34), although also significant for body contacts (U15: IRR = 0.54, 99% CI: 0.46-0.64; U18: IRR = 0.58, 99% CI: 0.48-0.70), other PCs, (U15: IRR = 0.60, 99% CI: 0.45-0.78; U18: IRR = 0.71, 99% CI: 0.58-0.88), and HCs (U15: IRR = 0.40, 99% CI: 0.22-0.71; U18: IRR = 0.37, 99% CI: 0.25-0.57). CONCLUSIONS: The incidence of BC was 82% lower in the U15 and 84% lower in U18 levels not allowing BC, with lower HC and other PC rates also in non-BC leagues. These findings demonstrate high adherence with BC policy change in youth ice hockey.

Incidence of Head Contacts, Penalties, and Player Contact Behaviors in Youth Ice Hockey: Evaluating the "Zero Tolerance for Head Contact" Policy Change.

BACKGROUND: To reduce the risk of concussion in youth ice hockey, Hockey Canada implemented a national "zero tolerance for head contact" (HC) policy in 2011. A previous cohort study revealed higher concussion rates after this implementation in players aged 11 to 14 years. However, it is unknown whether the elevated risk was due to higher HC rates or factors such as increased concussion awareness and reporting. PURPOSE: To compare the rates of primary and secondary HCs and HC policy enforcement in elite U15 ice hockey leagues (players <15 years) before (2008-2009) and after (2013-2014) the zero-tolerance policy change. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A total of 32 elite U15 games before (n2008-2009 = 16; 510 players) and after (n2013-2014 = 16; 486 players) HC policy implementation were video recorded. Videos were analyzed with validated criteria for identifying HC types (primary/direct contact by players [HC1], secondary/indirect contact via boards, glass, or ice surface [HC2]) and other player-to-player contact behavior. Referee-assessed penalties were cross-referenced with the official Hockey Canada casebook, and penalty types were displayed using proportions. Univariate Poisson regression (adjusted for cluster by team game, offset by game length [minutes]) was used to estimate HC incidence rates (IRs) and incidence rate ratios (IRRs) between cohorts. RESULTS: A total of 506 HCs were analyzed, 261 before HC policy implementation (IR, 16.6/100 team minutes) and 245 after implementation (IR, 15.5/100 team minutes). The HC1 rate (IRR, 1.05; 95% CI, 0.86-1.28) and HC2 rate (IRR, 0.74; 95% CI, 0.50-1.11) did not significantly differ before versus after implementation. Only 12.0% and 13.6% of HC1s were penalized pre- and postimplementation, respectively. Before implementation, HC1s were commonly penalized as roughing or elbowing penalties (59%), while after implementation, HC1s were penalized with the HC penalty (76%), and only 8% as roughing or elbowing. CONCLUSION: Despite implementation of the "zero tolerance for HC" policy, there was no difference in the rate of HC1s and HC2s or the proportion of HC1 penalized from before to after implementation. This research is instrumental in informing Hockey Canada's future referee training and rule enforcement modifications.

Effects of Caffeine on Exertion, Skill Performance, and Physicality in Ice Hockey.

PURPOSE: To determine the effects of low-dose caffeine supplementation (3 mg/kg body mass) consumed 1 h before the experiment on rating of perceived exertion (RPE), skills performance (SP), and physicality in male college ice hockey players. METHODS: Using a double-blind, placebo-controlled, randomized crossover experimental design, 15 college ice hockey players participated in SP trials and 14 participated in scrimmage (SC) trials on a total of 4 d, with prescribed ice hockey tasks occurring after a 1-h high-intensity practice. In the SP trials, time to complete and error rate for each drill of the validated Western Hockey League Combines Testing Standard were recorded. Peak head accelerations, trunk contacts, and offensive performance were quantified during the SC trials using accelerometery and video analysis. RPE was assessed in both the SP and SC trials. RESULTS: RPE was significantly greater in the caffeine (11.3 [2.0]) than placebo (9.9 [1.9]) condition postpractice (P = .002), with a trend toward greater RPE in caffeine (16.9 [1.8]) than placebo (15.7 [2.8]) post-SC (P = .05). There was a greater number of peak head accelerations in the caffeine (4.35 [0.24]) than placebo (4.14 [0.24]) condition (P = .028). Performance times, error rate, and RPE were not different between intervention conditions during the SP trials (P > .05). CONCLUSIONS: A low dose of caffeine has limited impact on sport-specific skill performance and RPE but may enhance physicality during ice hockey SCs.