Avenues for prevention using the epidemiology of sport-related concussion from a large high school surveillance study.

OBJECTIVE: Epidemiology provides fundamental opportunities to protect student-athlete health. The goal of this study was to describe the epidemiology of sport-related concussion (SRC) across 8 years (2015/2016-2022/2023) and compare boys' and girls' sports for SRC incidence and SRC mechanisms. METHODS: This was a retrospective cohort study performed using a statewide high school head injury surveillance system of high school student-athletes (n = 2,182,128; boys, n = 1,267,389; girls, n = 914,739). Exposures of interest included study year and boys and girls in comparable sports. Clinical incidence was calculated by dividing SRC counts in each sport by the number of participants per 100 player-seasons and presented with 95% CIs. The 2019/2020 and 2020/2021 data were included in the analysis, however caution is warranted due to the COVID-19 pandemic. Clinical incidence ratios (CIRs) were estimated for sex-comparable sports, and significance was determined if 95% CIs excluded 1.00. The authors compared mechanism of injury in boys' and girls' comparable sports with chi-square analyses (p < 0.05). RESULTS: Among 25,482 total SRCs, the overall clinical incidence of SRC for all boys and girls was 1.17 (95% CI 1.15-1.18) per 100 player-seasons across all years. Across all years, the overall clinical incidence in boys' sports was 1.34 (95% CI 1.32-1.36) per 100 player-seasons, and 0.93 (95% CI 0.91-0.95) per 100 player-seasons in girls' sports. Boys' sports with the highest clinical incidence included football, ice hockey, and wrestling. Girls' sports with the highest clinical incidence included basketball, soccer, lacrosse, competitive cheer, and gymnastics. Girls consistently had higher SRC rates relative to boys for baseball/softball, basketball, and soccer (CIR range 1.65 [95% CI 1.41-1.93] to 3.32 [95% CI 2.67-4.16]). Girls had lower SRC in lacrosse in 2015/2016 (CIR 0.63, 95% CI 0.40-0.97); no difference in 2016/2017-2020/2021, but had higher clinical incidence in 2021/2022 (CIR 1.69, 95% CI 1.18-2.44) relative to boys. In boys the most common mechanism of SRC occurred from person-to-person contact (n = 8752, 62.8%), whereas girls commonly sustained SRC from person-to-object contact (n = 2369, 33.4%) and from person-to-person contact (n = 2368, 33.4%). There were significant associations between boys' versus girls' sports and mechanism of injury within baseball/softball (χ2 = 12.71, p = 0.005); basketball (χ2 = 36.47, p < 0.001); lacrosse (χ2 = 185.15, p < 0.001); and soccer (χ2 = 122.70, p < 0.001). CONCLUSIONS: These findings can help understand the potential impact of interventions aimed at preventing or reducing SRC. Including girls' sports within this study extends research for a largely underrepresented group.

Comparison of different definitions of traumatic brain injury: implications for cohort characteristics and survival in women, Philadelphia, USA.

BACKGROUND: Traumatic brain injury (TBI) is an acute injury that is understudied in civilian cohorts, especially among women, as TBI has historically been considered to be largely a condition of athletes and military service people. Both the Centres for Disease Control and Prevention (CDC) and Department of Defense (DOD)/Veterans Affairs (VA) have developed case definitions to identify patients with TBI from medical records; however, their definitions differ. We sought to re-examine these definitions to construct an expansive and more inclusive definition among a cohort of women with TBI. METHODS: In this study, we use electronic health records (EHR) from a single healthcare system to study the impact of using different case definitions to identify patients with TBI. Specifically, we identified adult female patients with TBI using the CDC definition, DOD/VA definition and a combined and expanded definition herein called the Penn definition. RESULTS: We identified 4446 adult-female TBI patients meeting the CDC definition, 3619 meeting the DOD/VA definition, and together, 6432 meeting our expanded Penn definition that includes the CDC ad DOD/VA definitions. CONCLUSIONS: Using the expanded definition identified almost two times as many patients, enabling investigations to more fully characterise these patients and related outcomes. Our expanded TBI case definition is available to other researchers interested in employing EHRs to investigate TBI.

Parent and Youth Athlete Perceptions of Concussion Injury: Establishing a Factor Structure.

OBJECTIVE: The first objective was to establish the respective factor structures of a concussion perceptions inventory that was adapted for youth athletes (ages 8-14 years) and their parents from the Perceptions of Concussion Inventory for Athletes. The second objective was to understand the associations between the concussion perceptions of youth athlete-parent dyads. METHOD: In this cross-sectional study, 329 parent-youth athlete dyads completed a respective concussion perception inventory. Mean age of youth respondents was 10.9 ± 1.8 years (70.1% male) and mean age of parent respondents was 40.5 ± 13.6 years (60.9% female). RESULTS: Exploratory factor analyses revealed unique 7-factor structures for both the youth athlete and parent inventories (youth athlete: anxiety, clarity, treatment, permanent injury, symptom variability, long-term outcomes, and personal control; parent: anxiety, clarity, treatment, permanent injury, symptom variability, and long-term outcomes, and affect others). Weak associations were found between dyads on the 5 factors that were composed of identical items (anxiety, clarity, treatment, permanent injury, and symptom variability). CONCLUSIONS: Findings suggest that this adapted inventory has adequate psychometric properties to be used in the study of the concussion perceptions of youth athletes and their parents. Weak correlations across the concussion perceptions in the dyads suggest that parents and children hold different concussion perceptions and this should be considered in instrument selection of future studies.

Acute Sport-Related Concussion Management and Return to Sport Time in High School Athletes.

BACKGROUND: The current evidence for acute management practices of sport-related concussion (SRC) is often limited to in-clinic visits, with limited studies identifying professionals in early SRC care and the association with prolonged recovery outcomes. PURPOSE: To describe acute SRC management practices (ie, the personnel in the initial evaluations, removal from activity) and test the association with prolonged return to sport (RTS) time. STUDY DESIGN: Descriptive epidemiology study. METHODS: We conducted a retrospective cohort study of 17,081 high school SRCs accrued between the 2015-2016 and 2020-2021 academic years. We reported acute management practices and RTS time as frequencies stratified by sex, sport, and event type and compared athletic trainer (AT) access in initial evaluation with chi-square tests (P < .05). Separate logistic regressions estimated odds ratios (ORs) and 95% CIs for removal from activity and prolonged RTS >21 days by acute management practices. RESULTS: Most SRCs (n = 12,311 [72.1%]) had complete initial evaluation by an AT. Boys had an AT evaluation in 75.5% (n = 2860/3787) of practice-related and 74.8% (n = 5551/7423) of competition-related events. Girls had an AT evaluation in 61.3% (n = 1294/2110) of practice-related and 69.3% (n = 2606/3761) of competition-related events. In sex-comparable sports (n = 6501), there was no difference between boys (n = 1654/2455 [67.4%]) and girls (n = 2779/4046 [68.7%]) having an AT involved in the first evaluation (χ2 = 1.21; P = .27). Notably, 25.3% of girls' SRCs were evaluated by a coach alone, and we observed differences in personnel in initial evaluations by sport. The odds of immediate removal were higher when an AT made the initial evaluation (OR, 2.8 [95% CI, 2.54-3.08]). The odds of prolonged RTS >21 days was lower for those with an AT in the initial evaluation (OR, 0.74 [95% CI, 0.65-0.84]) adjusting for significant factors from univariate analyses, boys relative to girls (OR, 0.85 [95% CI, 0.76-0.96]), specialty care relative to PCP (OR, 2.16 [95% CI, 1.90-2.46]), specialty care relative to urgent or ready care (OR, 0.99 [95% CI, 0.82-1.22]) concussion history (OR, 1.41 [95% CI, 1.22-1.63]), and removal from activity (OR, 0.90 [95% CI, 0.78-1.05]). CONCLUSION: This study found variability in personnel involved in initial SRC evaluations, with higher percentages of athletes with SRCs having ATs make the initial evaluation during competitive events. There was no association between sex and AT involvement in comparable sports. There was an association between prolonged RTS and AT involvement, sex, concussion history, and location of follow-up care.

Publicly available data sources in sport-related concussion research: a caution for missing data.

BACKGROUND: Researchers often use publicly available data sources to describe injuries occurring in professional athletes, developing and testing hypotheses regarding athletic-related injury. It is reasonable to question whether publicly available data sources accurately indicate athletic-related injuries resulting from professional sport participation. We compared sport-related concussion (SRC) clinical incidence using data from publicly available sources to a recent publication reporting SRC using electronic health records (EHR) from the National Football League (NFL). We hypothesize publicly available data sources will underrepresent SRC in the NFL. We obtained SRCs reported from two publicly available data sources (NFL.com, pro-football-reference.com) and data reported from the NFL's published EHR. We computed SRC per 100 unique player signings from 2015-2019 and compared the clinical incidence from publicly available data sources to EHR rates using clinical incidence ratios (CIR) and 95% confidence intervals (CI). FINDINGS: From 2015-2019, SRC counts from published EHR record data ranged from 135-192 during the regular season, whereas SRC counts ranged from 102-194 and 69-202 depending on the publicly available data source. In NFL.com the SRC clinical incidence was significantly and progressively lower in 2017 (CIR: 0.73, 95% CI: 0.58-0.91), 2018 (CIR: 0.66, 95% CI: 0.50-0.87), and 2019 (CIR: 0.48, 95% CI: 0.35-0.64) relative to the gold-standard EHR. In the pro-football-reference.com data, the documented SRCs in publicly available data sources for other years were ~ 20-30% lower than the gold-standard EHR numbers (CIRs 0.70-0.81). CONCLUSIONS: Publicly available data for SRCs per 100 unique player signings did not match published data from the NFL's EHR and in several years were significantly lower. Researchers should use caution before using publicly available data sources for injury research.

Long-term test-retest reliability of the vestibular/ocular motor screening for concussion in child athletes: A preliminary study.

The Vestibular/Ocular Motor Screening (VOMS) is a sport-related concussion screening tool that assesses vestibular ocular reflex (VOR) and oculomotor symptom provocation. Long-term test-retest reliability of the VOMS over multiple athletic seasons has not yet been established in a pediatric population. Fifty-one child athletes (females = 28, 54.9%) 8-13 years of age, completed a baseline VOMS assessment at two timepoints, 18 months apart. Cronbach's alpha was used to examine the internal consistency at both time points. Two-way mixed intra-class correlation coefficients and Cohen's Kappa statistics were used to evaluate test-retest reliability. High internal consistency existed at both initial (α = 0.91) and follow-up (α = 0.95) for VOMS symptom provocation items. Strong inter-item correlations were noted between vertical VOR (r = ≥0.70) and visual motion sensitivity (VMS) (r = ≥0.70). Fair agreement was produced for convergence (κ = 0.23, vertical VOR (κ = 0.25) and VMS (κ = 0.25), as well as reliability on NPC distance (ICC2,k = 0.31). All other VOMS scores yielded poor agreement between time points. Symptom provocation was the same for 49% of athletes between timepoints, while 31.4% had a decrease in scoring at follow-up. Symptom provocation from VOMS tasks lessened with increasing age and time; therefore, clinicians should consider annual baseline testing to improve accuracy for concussion evaluation and management in pediatrics.

Agreement between parent reported and child self-reported sport-related concussion history: A brief report.

This cross sectional investigation measured the agreement between parent report of their 8-14 year old child's sport-related concussion (SRC) history and their child's self-report of their own SRC history. Parent-child dyads (n = 405) within a youth contact sports (e.g., football, ice hockey, lacrosse, soccer) setting participated in the study. Parents (6.2%) and 8.6% of children self-reported a history of at least one diagnosed SRC. We observed substantial agreement between the number of parent-reported and child self-reported SRCs (κ = 0.613, p ≤ .001). Partial agreement regarding the number of SRCs reported by both groups was also substantial (weighted κ = 0.693, p ≤ .001). Removing dyads where neither the parent nor the child reported a diagnosed SRC, sensitivity analyses revealed only fair agreement in parent-child SRC recall. These results indicate that parents and youth athletes overall accounts of their diagnosed SRC history correspond. However determining specifics (e.g., total concussion counts) may benefit from concurrent parent reports, or documented events in medical histories.

Cognitive and Behavioral Outcomes in Male and Female NCAA Soccer Athletes across Multiple Years: A CARE Consortium Study.

PURPOSE: The purpose of this study was to determine changes in neurocognitive, psychosocial, and balance functioning in collegiate male and female soccer players across three consecutive years of baseline testing compared with a control group of noncontact athletes. METHODS: Generalized estimating equations were used to compare changes in annual, preseason baseline measures of neurocognitive function, neurobehavioral and psychological symptoms, and postural stability between collegiate soccer players ( n = 75; 51 [68%] female soccer players) and noncontact athletes ( n = 210; 133 [63%] female noncontact athletes) across three consecutive years. RESULTS: Among all participants, the group-time interaction was not significant for any outcome measures. Overall, soccer players reported lower (better) Brief Symptom Inventory 18 Depression ( P = 0.004, Exp(B) = 0.36, 95% confidence interval [CI] = 0.18-0.73), Global Severity Index ( P = 0.006, Exp(B) = 0.53, 95% CI = 0.33-0.84), and Post-Concussion Symptom Scale Symptom Severity ( P < 0.001, Exp(B) = 0.45, 95% CI = 0.22-0.95) scores than noncontact athletes. No other outcome measures were different between soccer players and noncontact athletes. CONCLUSIONS: Among collegiate athletes, soccer players report similar or better psychosocial functioning and symptom scores than noncontact athletes. Importantly, neurocognitive functioning, neurobehavioral and psychological symptoms, and postural stability do not worsen over time in collegiate soccer players relative to their noncontact counterparts. Our findings suggest that despite possible exposure to repetitive head impacts, collegiate soccer players do not exhibit changes in observable function and symptoms across multiple seasons.

The Role of Reported Affective Symptoms and Anxiety in Recovery Trajectories After Sport-Related Concussion.

BACKGROUND: There is growing awareness and clinical interest in athletes with affective symptoms after sport-related concussion (SRC), as these symptoms may contribute to overall symptoms and represent a modifiable risk factor of longer recovery. However, evidence of their effects on the entire return-to-play (RTP) trajectory, particularly among women and men, is limited. PURPOSE/HYPOTHESIS: To examine the relationship between affective symptom reporting and RTP progression after SRC among a cohort of Division 1 student-athletes. We hypothesized that those endorsing affective symptoms, specifically nervous-anxious symptoms, spend more time in RTP progression and recovery. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Using SRC data from the Ivy League-Big Ten Epidemiology of Concussion Study among varsity athletes through February 2020, we identified the 4 affective symptoms from the Sport Concussion Assessment Tool symptom inventory. We modeled the relationship between a 4-category affective symptom variable and time to symptom resolution, RTP, and RTP progression, adjusting for nonaffective symptom prevalence and concussion history. Cox regressions were used to estimate hazard ratios for time to event outcomes, and linear regressions were used to evaluate mean differences for continuous outcomes. RESULTS: Among 2077 student-athletes (men, 63.5%) with SRC symptoms, affective symptom prevalence was 47.6% and 44.3% in women and men, respectively, and nervous-anxious prevalence was 24.2% and 22.5%, respectively. When comparing women with and without co-occurring affective symptoms, rates of symptom resolution and RTP were significantly lower in those with affective symptoms, and women with nervous-anxious symptoms spent significantly longer in RTP progression. When comparing men with and without co-occurring affective symptoms, rates of symptom resolution and RTP were significantly lower in those with co-occurring affective symptoms, and affective symptoms were not associated with time in RTP progression. CONCLUSION: Student-athletes with affective symptoms and nervous-anxious symptoms exhibited delayed clinical recovery and RTP timelines, particularly for time in RTP. Symptom prevalence and concussion history contributed to this; however, unmeasured confounding remains, as indicated by the poor model fit. This study motivates future work to explore affective symptoms and RTP timelines, considering anxiety and risk/protective factors over time.

Progression through return-to-sport and return-to-academics guidelines for concussion management and recovery in collegiate student athletes: findings from the Ivy League-Big Ten Epidemiology of Concussion Study.

OBJECTIVE: To examine the progression of collegiate student athletes through five stages of a return-to-activity protocol following sport-related concussion (SRC). METHODS: In a multisite prospective cohort study, we identified the frequency of initial 24-48 hours physical and cognitive rest, and the sequence of (1) symptom resolution and return to (2) exertion activity, (3) limited sport, (4) full sport and (5) full academics. In resulting profiles we estimated the likelihood of return to full sport ≤14 days or prolonged >28 days and tested for variability based on timing of the stages. RESULTS: Among 1715 athletes with SRC (31.6% females), 67.9% had 24-48 hours initial physical and cognitive rest. The median was 6 days to return to full academics, 8 days to symptom resolution and 9 days to exertion. Three profiles emerged; all had the same sport-specific return progression, but varied in the relative timing of full academics. In unadjusted analyses, full academics as the first stage corresponded to the longest time to return to full sport, and initiating exertion the same day as symptom resolution resulted in the shortest time. In adjusted regression analyses, athletes initiating full academics while still symptomatic were 21.5% less likely (95% CI -27.4% to -15.5%) to return to full sport ≤14 days and, analogously, 19.1% more likely (95% CI 13.4% to 24.7%) to have prolonged return >28 days. While additionally controlling for initial rest, sex, symptom count and concussion history, the likelihood of prolonged return >28 days was 37.0% (95% CI 25.2% to 48.8%) in athletes initiating exertion considerably before symptoms resolved (ie, 7+ days), but only 3.6% (95% CI -1.4% to 8.6%) in athletes initiating exertion shortly before achieving symptom resolution (ie, 3-4 days). CONCLUSION: We found evidence that sequential progressions were consistent with current recommendations including brief initial rest, and the initiation and relative timing of each stage impacted the final return-to-sport outcome.

Detection of astrocytic tau pathology facilitates recognition of chronic traumatic encephalopathy neuropathologic change.

Traumatic brain injury (TBI) is associated with the development of a range of neurodegenerative pathologies, including chronic traumatic encephalopathy (CTE). Current consensus diagnostic criteria define the pathognomonic cortical lesion of CTE neuropathologic change (CTE-NC) as a patchy deposition of hyperphosphorylated tau in neurons, with or without glial tau in thorn-shaped astrocytes, typically towards the depths of sulci and clustered around small blood vessels. Nevertheless, although incorporated into consensus diagnostic criteria, the contribution of the individual cellular components to identification of CTE-NC has not been formally evaluated. To address this, from the Glasgow TBI Archive, cortical tissue blocks were selected from consecutive brain donations from contact sports athletes in which there was known to be either CTE-NC (n = 12) or Alzheimer's disease neuropathologic change  (n = 4). From these tissue blocks, adjacent tissue sections were stained for tau antibodies selected to reveal either solely neuronal pathology (3R tau; GT-38) or mixed neuronal and astroglial pathologies (4R tau; PHF-1). These stained sections were then randomised and independently assessed by a panel of expert neuropathologists, blind to patient clinical history and primary antibody applied to each section, who were asked to record whether CTE-NC was present. Results demonstrate that, in sections stained for either 4R tau or PHF-1, consensus recognition of CTE-NC was high. In contrast, recognition of CTE-NC in sections stained for 3R tau or GT-38 was poor; in the former no better than chance. Our observations demonstrate that the presence of both neuronal and astroglial tau pathologies facilitates detection of CTE-NC, with its detection less consistent when neuronal tau pathology alone is visible. The combination of both glial and neuronal pathologies, therefore, may be required for detection of CTE-NC.

Design and Evaluation of a Postpartum Depression Ontology.

OBJECTIVE: Postpartum depression (PPD) remains an understudied research area despite its high prevalence. The goal of this study is to develop an ontology to aid in the identification of patients with PPD and to enable future analyses with electronic health record (EHR) data. METHODS: We used Protégé-OWL to construct a postpartum depression ontology (PDO) of relevant comorbidities, symptoms, treatments, and other items pertinent to the study and treatment of PPD. RESULTS: The PDO identifies and visualizes the risk factor status of variables for PPD, including comorbidities, confounders, symptoms, and treatments. The PDO includes 734 classes, 13 object properties, and 4,844 individuals. We also linked known and potential risk factors to their respective codes in the International Classification of Diseases versions 9 and 10 that would be useful in structured EHR data analyses. The representation and usefulness of the PDO was assessed using a task-based patient case study approach, involving 10 PPD case studies. Final evaluation of the ontology yielded 86.4% coverage of PPD symptoms, treatments, and risk factors. This demonstrates strong coverage of the PDO for the PPD domain. CONCLUSION: The PDO will enable future researchers to study PPD using EHR data as it contains important information with regard to structured (e.g., billing codes) and unstructured data (e.g., synonyms of symptoms not coded in EHRs). The PDO is publicly available through the National Center for Biomedical Ontology (NCBO) BioPortal ( https://bioportal.bioontology.org/ontologies/PARTUMDO ) which will enable other informaticists to utilize the PDO to study PPD in other populations.

Factors associated with parent and youth athlete concussion knowledge.

INTRODUCTION: On-site health care providers are not routinely present at all youth sport events. Therefore, parents and youth athletes are often responsible for identifying and making appropriate immediate care decisions regarding concussions, which may be influenced by their injury health literacy. Previous studies have investigated the level of concussion knowledge of parents and athletes, but few have investigated factors associated with greater awareness at the youth sport level specifically. METHOD: A total of 466 parents and 390 youth contact sport athletes from Pennsylvania and Michigan completed separate surveys of concussion knowledge and personal and family demographic information. RESULTS: Parents had a mean concussion knowledge score of 39.3 ±â€¯4.6 out of a possible 47 points. Having a medical occupation (p = .04) and being older in age (p = .03) were associated with higher concussion knowledge scores in parents (R2 = 0.018; 95% CI = 32.77-38.99). Youth athletes had a mean concussion knowledge score of 35.0 ±â€¯5.7 out of 47. Having learned about concussion previously (p < .001), having a history of diagnosed concussion(s) (p = .01), sport type (relative to girls' ice hockey, p < .001), older age (p < .001), and parent concussion knowledge (p = .04) were associated with higher youth athlete concussion knowledge (R2 = 0.176; 95% CI = 19.08-31.72). CONCLUSIONS: More evidence-based concussion awareness resources are needed at the youth sport level. While it did not significantly influence concussion knowledge for parents, concussion education is a modifiable factor that may be essential for improving concussion knowledge of youth athletes, thus warranting further study into effective awareness strategies for this population. Practical Applications: The factors found to influence concussion knowledge in this study could be considered in future educational concussion initiatives for youth athletes and their parents in order to increase awareness regarding the potential dangers of participating in sport while concussed.

A standardized method for quantifying and characterizing repetitive head impacts in soccer matches using video footage.

Soccer athletes experience repetitive head impacts (RHI) through purposeful heading and unintentional head impacts, which may be associated with acute and chronic brain injury. Previous soccer studies have sought to quantify and characterize RHI, but to-date no consistent, standardized methods exist. The Heads-Up Checklist (HUC), originally used for characterizing head impacts in hockey, was modified to be used in soccer (soccer HUC [SHUC]). Our aim was to determine the reliability of quantifying ball-to-head impacts using video verification and to develop and test the reliability of the SHUC to characterize RHI in soccer. Two trained reviewers used the SHUC to quantify ball-to-head impacts and characterize non-ball-to-head impacts in 38 male and female collegiate soccer matches. Intraclass correlation coefficient (ICC) and Cohen's Kappa were used to assess interrater reliability. Independent t-tests and chi-square analyses were used to examine sex differences. The interrater reliability for quantifying ball-to-head impacts was excellent (ICC = 0.97); however, only half of the non-ball-to-head impact characteristics had acceptable interrater reliability with two reviewers. The number of ball-to-head-impacts and RHI characteristics were consistent between males and females (gggp > 0.05). Our results suggest that the SHUC is an applicable standardized method to quantify and characterize RHI from video footage of soccer matches; however, accurately characterizing some aspects of RHI is a challenging task that may be supplemented by head impact sensor data.

Avenues for Sport-Related Concussion Prevention in High School Football: Effect of Limiting Collision Practices.

CONTEXT: Football continues to demonstrate the highest rate of sport-related concussion (SRC) in high school athletics. To mitigate the SRC risk, the Michigan High School Athletic Association (MHSAA) implemented rules aimed at reducing the number of collisions occurring in practices. OBJECTIVE: To estimate the rates of SRC in MHSAA football programs and evaluate progressive limitations to collision practices over 5 consecutive seasons. DESIGN: Retrospective cohort study. SETTING: Michigan high school football. PATIENTS OR OTHER PARTICIPANTS: High school (9th-12th grade) football athletes (>99% male) participating in MHSAA-sanctioned events. MAIN OUTCOME MEASURE(S): Designated administrators at each school recorded the total number of participating athletes and SRCs (defined as head injuries resulting from athletic participation that required the student-athletes to be withheld from activity after exhibiting signs, symptoms, or behaviors consistent with an SRC) in the MHSAA injury-surveillance system each season (2015-2016 through 2019-2020). Progressive limitations to collision practices occurred across the study period. We estimated athlete-exposures (AEs) as the total number of players multiplied by the total number of possible practices (11 weeks, 4 days each) or competitions (9 weeks, 1 day each) during each season. Incidence rates and rate ratios (RRs) with 95% CIs were used to compare practice and competition SRCs and each season with the most recent season. RESULTS: A total of 7755 football SRCs were diagnosed across the 5-year period. The overall SRC rate was 8.03 per 10 000 AEs (95% CI = 7.85, 8.21). The competition SRC rate (30.13/10 000 AEs) was higher than the practice rate (3.51/10 000 AEs; RR = 8.58; 95% CI = 8.19, 9.00). The practice SRC rate was lower in 2017-2018 (RR = 0.86; 95% CI = 0.77, 0.97), 2018-2019 (RR = 0.89; 95% CI = 0.79, 1.0), and 2019-2020 (RR = 0.83; 95% CI = 0.74, 0.94) relative to 2015-2016. CONCLUSIONS: We found that the progressive limitations to collision practices were protective against SRCs, as the rate of SRC was lower in the 3 most recent seasons relative to 2015-2016.

Concussion Nondisclosure in Youth Sports.

CONTEXT: Researchers conducting studies about sport-related concussion (SRC) reporting behaviors and reasons for nondisclosure primarily focus on older athletic populations. Youth athletes participating in contact sports are also at risk for SRC; however, little is known about their SRC disclosure patterns and reasons for nondisclosure. OBJECTIVE: To examine the self-reported SRC history and reasons for SRC nondisclosure of youth athletes aged 8-14 years. DESIGN: Cross-sectional study. SETTING: Youth athletes in organized football, ice hockey, lacrosse, or soccer. PATIENTS OR OTHER PARTICIPANTS: A total of 411 youth athletes (boys = 70.0% [n = 287/410]; median age = 11 [interquartile range = 10-13] years). MAIN OUTCOME MEASURE(S): A 15-minute survey including self-reported demographics, diagnosed and nondisclosed SRC history, and reasons for nondisclosure of suspected SRCs. RESULTS: Ten percent of respondents (n = 41/411) recounted ≥1 diagnosed SRC, 12.7% (n = 52/411) did not report a suspected SRC, 13.1% (n = 53/404) indicated they continued to practice, and 12.3% (n = 50/406) reported they continued to play in a game after a suspected SRC. Significant associations between sport and nondisclosure existed (P values < .001) but not with self-reported concussion history (P = .14). In sex-comparable analyses, boys' lacrosse players had a higher frequency of nondisclosure than girls (P = .05). The most common reasons for nondisclosure were not wanting to lose playing time (66.7%, n = 32/48), miss a game (56.3%, n = 27/48), and let the team down (43.8%, n = 21/48) and uncertainty over injury severity and the presence of SRC (43.8%, n = 21/48). CONCLUSIONS: Ten percent of youth athletes self-reported at least 1 diagnosed SRC. However, they also described continuing to practice or play in a game after a suspected SRC. Reasons for nondisclosure at this age were similar to those reported in high school and collegiate athletes. Recent researchers suggested negative consequences of continued play with SRC, especially in the acute stages. Anyone conducting future educational initiatives should emphasize these risks and focus on reasons why athletes of both sexes withhold reporting.

Examining Concussion Nondisclosure in Collegiate Athletes Using a Health Disparities Framework and Consideration of Social Determinants of Health.

CONTEXT: Limited research exists concerning the relationship between the social determinants of health (SDOHs), including race, socioeconomic status (SES), health care access and physical environment and concussion nondisclosure in collegiate athletes. However, among high school athletes, disparities have been noted, with Black athletes who attended under-resourced schools and lacked access to an athletic trainer (AT) disclosing fewer concussions. OBJECTIVE: To investigate whether concussion nondisclosure disparities existed by (1) race, (2) SES, or (3) AT health care access before college and understand the differential reasons for concussion nondisclosure between White and Black collegiate athletes. DESIGN: Cross-sectional study. SETTING: Collegiate athletics. PARTICIPANTS: A total of 735 college athletes (84.6% White, 15.4% Black). MAIN OUTCOME MEASURE(S): Participants completed a questionnaire that directly assessed concussion nondisclosure, including reasons for not reporting a suspected concussion. With the premise of investigating SDOHs, race was the primary exposure of interest. The outcome of interest, nondisclosure, was assessed with a binary (yes or no) question, "Have you ever sustained a concussion that you did not report to your coach, AT, parent, teammate, or anyone else?" RESULTS: Among the White and Black athletes, 15.6% and 17.7%, respectively, reported a history of concussion nondisclosure. No differences were found by race for distributions of history of concussion nondisclosure (P = .57). Race was not associated with concussion nondisclosure when evaluated as an effect modification measure or confounder, and no significant associations were noted by SES or high school AT access. Differences by race for reported reasons for nondisclosure were present for "At the time, I did not think it was a concussion" (P = .045) and "I thought my teammates would think I am weak" (P = .03), with Black athletes selecting these more frequently than White athletes. CONCLUSIONS: These data help to contextualize race and its intersection with other SDOHs that could influence concussion nondisclosure outcomes in collegiate athletes.

Clinical Recovery Timelines After Sport-Related Concussion in Men's and Women's Collegiate Sports.

CONTEXT: Researchers have identified sex differences in sport-related concussion incidence and recovery time; however, few have examined sex differences in specific recovery trajectories: time to symptom resolution, return to academics, and return to athletic activity across collegiate sports. OBJECTIVE: To examine sex differences in sport-related concussion recovery trajectories across a number of club and varsity sports with different levels of contact. DESIGN: Descriptive epidemiology study. SETTING: Collegiate varsity and club sports. PATIENTS OR OTHER PARTICIPANTS: Sport-related concussions sustained by student-athletes (n = 1974; women = 38.8%) participating in Ivy League sports were monitored between 2013-2014 and 2018-2019. MAIN OUTCOME MEASURE(S): Athletic trainers collected concussive injury and recovery characteristics as part of the Ivy League-Big Ten Epidemiology of Concussion Study's surveillance system. Time to symptom resolution, return to academics, and return to limited and full sport participation were collected. Survival analyses determined the time from injury to each recovery outcome for male and female athletes by sport. Peto tests were used to compare recovery outcomes between men's and women's sports and by sport. RESULTS: The median (interquartile range [IQR]) was 9 days (IQR = 4-18 days) for time to symptom resolution overall, 8 days (IQR = 3-15 days) for return to academics, 12 days (IQR = 8-23 days) for return to limited sport participation, and 16 days (IQR = 10-29 days) for return to full sport participation. We observed differences overall between sexes for median time to symptom resolution (men = 8 days [IQR = 4-17 days], women = 9 days [IQR = 5-20 days]; P = .03) and return to academics (men = 7 days [IQR = 3-14 days], women = 9 days [IQR = 4-17 days]; P < .001) but not for median time to return to athletics (limited sport participation: P = .12, full sport participation: P = .58). Within-sport comparisons showed that women's lacrosse athletes had longer symptom resolution (P = .03) and return to academics (P = .04) compared with men's lacrosse athletes, whereas men's volleyball athletes took longer to return to limited (P = .02) and full (P = .049) sport participation than women's volleyball athletes. CONCLUSIONS: Recovery timelines between sexes were different. Athletes in women's sports experienced longer symptom durations and time to return to academics compared with men's sports, but athletes in men's and women's sports presented similar timelines for return to athletics.

Epidemiology of Injuries in National Collegiate Athletic Association Women's Lacrosse: 2014-2015 Through 2018-2019.

CONTEXT: Lacrosse is an increasingly popular sport; the number of teams participating in collegiate women's lacrosse has increased by 21.4% in the past 5 years. BACKGROUND: The growth of National Collegiate Athletic Association women's lacrosse, coupled with the ongoing discussions surrounding protective equipment, necessitates further epidemiologic studies in this population. METHODS: Exposure and injury data collected in the National Collegiate Athletic Association Injury Surveillance Program during 2014-2015 through 2018-2019 were analyzed. Injury counts, rates, and proportions were used to describe injury characteristics, and injury rate ratios with 95% CIs were used to examine differential injury rates. RESULTS: The overall injury rate was 4.99 per 1000 athlete exposures. Less than 30% of injuries were time-loss injuries; injuries were most commonly attributed to noncontact (26.6%) and overuse (25.2%) mechanisms. The most commonly reported specific injuries were lateral ligament complex tears (ankle sprains; 9.1%), concussions (7.2%), and hamstring tears (3.8%). SUMMARY: Findings from this study were consistent with the existing epidemiologic evidence in previous studies. Injury incidence in practices, in preseason, and as a result of player contact warrant further attention in this population.

Epidemiology of Injuries in National Collegiate Athletic Association Men's Lacrosse: 2014-2015 Through 2018-2019.

CONTEXT: The popularity of National Collegiate Athletic Association (NCAA) men's lacrosse has been steadily increasing since the early 1980s. BACKGROUND: Injury surveillance is an important tool to aid in identifying emerging patterns of sport-related injury in NCAA men's lacrosse. METHODS: Injury data collected from a sample of men's lacrosse teams through the NCAA Injury Surveillance Program for the academic years 2014-2015 through 2018-2019 were analyzed. Athlete exposures were estimated and computed based on collected exposure data. Injury counts, rates, and proportions were used to describe injury characteristics, and injury rate ratios (IRRs) with 95% confidence intervals (CIs) were calculated to estimate differences in injury rates. RESULTS: The overall injury rate was 4.90 per 1000 athlete exposures (AEs), and the competition injury rate was higher than the practice injury rate (IRR = 2.59; 95% CI = 2.35, 2.84). The overall preseason injury rate was higher than the regular and postseason injury rates. The most reported injuries were concussions (8.0%), ankle sprains (7.7%), and hamstring tears (6.9%). CONCLUSIONS: Study findings were comparable with existing epidemiological evidence. The overall burden of concussions and lower extremity injuries warrant further attention in this population.