Sports Medicine

Epidemiological analysis of pediatric baseball and softball concussions in United States emergency departments

a b s t r a c t

Purpose: To evaluate the epidemiology of concussions in pediatric baseball and softball players. We hypothesized that head-to-ball injuries would be the most common cause of concussions.

Methods: The National Electronic Injury surveillance System (NEISS) database was used to gather data. Concussions occurring during baseball and softball participation in pediatric patients (4-17 years old) from 2012 to 2021 was gathered. concussion mechanisms were grouped into 5 categories: head-to-player, head-to- ball, head-to-surface (ground, walls, railings), head-to-bat, and unknown. Linear regression models were used to assess changes in yearly concussion rates over the study period. Results from these models were reported using parameter estimates and the estimated Pearson correlation coefficient.

Results: A weighted total of 54,978 baseball and softball related concussion injuries were analyzed. The average weighted age of our cohort at the time of injury was 13.1 years, with 54.1% (n = 29,761) of concussions occurring in males. The national estimated incidence of concussion injuries decreased non-significantly over the study period (slope estimate = -311 concussions/year, r = -0.625, p-value = 0.054). The majority of weighted na- tional estimate concussions were due to head-to-ball injuries (n = 34,650; 63.0%), followed by head-to-player (n = 8501; 15.5%), head-to-surface (n = 5347; 9.7%), and head-to-bat (n = 5089; 9.3%). On sub-analysis, individuals were grouped into 3 age brackets: 4-8, 9-13, and 14-17 years. The most common mechanism of concussions in children of all ages was head-to-ball. The incidence of head-to-player and head-to-surface injuries increased throughout each age group, while head-to-bat decreased.

Conclusion: The incidence of concussions in pediatric baseball and softball athletes has been decreasing non- significantly over our 10-year study period. The most common mechanism of concussions in our study was head-to-ball injuries.

(C) 2023

  1. Introduction

Of all sport injuries in recent years, discussions on the prevention of concussions have been on the forefront of media relations for sport leagues [1-3]. The National Football League has been in the spotlight to protect its athletes from concussions, as football has a high rate of concussions at 61.7 concussions per 100 regular season games [4]. Although not as prevalent, concussions in baseball and

* Corresponding author at: Department of Orthopaedic Surgery and Sports Medicine, University of Kentucky, 2195 Harrodsburg Rd, Lexington, KY 40504, United States of America.

E-mail addresses: [email protected] (V. Abed), [email protected] (G.S. Hawk), [email protected] (C. Conley), [email protected] (R. Akarakian), [email protected] (A.V. Stone).

softball are also an issue [5-8]. A concussion rate of 0.05 per 1000 athletic exposures (AE) has been calculated for high school baseball players and 0.07 per 1000 AE for high school softball players [9]. With the push to lower concussion rates given the Long-term effects they may cause [10,11], it is important to not only focus on adults, but children as well. Since the participation of children in youth sports has been increasing in the last decade [12,13], assessing and examining this population is essential.

Repeated concussions are detrimental to a person’s health [10,11], and these effects are more severe for the underdeveloped nervous system of children and adolescents [12,13]. Younger athletes have shown to have long lasting symptoms and cognitive defects even after returning to play [12,14]. Specifically, for 15 to 24 year olds, sport partic- ipation is second to motor vehicle crashes as the cause of traumatic

https://doi.org/10.1016/j.ajem.2023.04.025

0735-6757/(C) 2023

brain injury [9]. With baseball and softball being a common sport children play, it is important to analyze this population.

The purpose of the study was to evaluate the epidemiology of concus- sions in pediatric baseball and softball players. We hypothesized that head-to-ball injuries would be the most common cause of concussions.

  1. Methods
    1. National electronic injury surveillance system

Our study utilized the National Electronic Injury Surveillance System database, which is overseen by the Consumer Product Safety Commission (CPSC). Emergency departments (EDs) in the United States (US) are sampled by the CPSC, with the NEISS being a probability sample of 100 hospitals in the US [12,13]. The sample of hospitals are spread geographically across the US, which include both academic and community hospitals [13,15]. Patient demographics, injury diagnosis and details, location of injury, disposition, and narratives are recorded for each encounter and reported in the NEISS database [13,15].

Concussions occurring during baseball and softball participation in pediatric patients (4-17 years old) from 2012 to 2021 was gathered. Specific codes were used to identify patients (baseball: 5041 and softball: 5034). The body part code for head injuries was 75 and the diagnosis code of concussions was 52. The narratives for each patient en- counter were reviewed to gather the mechanism of injury and discharge disposition. Concussion narratives were grouped into 5 categories: head- to-player, head-to-ball, head-to-surface (ground, walls, railings), head- to-bat, and unknown. Exclusion criteria included a mechanism of injury not related to baseball, softball, or describing bystanders.

    1. Data analysis

Concussion counts were tabulated by year, both overall and broken out by gender. The overall incidence due to each cause was tabulated, both overall and broken out by year. Linear regression models were used to assess changes in yearly concussion rates over the study period. Results from these models were reported using parameter estimates and the estimated Pearson correlation coefficient.

A sub-analysis was also performed by repeating the above-

mentioned statistical analysis with the removal of the 2020 year.

Removal of the 2020 year was performed due to the impact the COVID-19 pandemic had on sport participation [16].

All of the above analyses were done using NEISS full-Sample weights. Across all analyses, a p-value of <0.05 was considered significant. All analyses were completed in R 4.2.1 (R Foundation for Statistical Computing; Vienna, Austria).

  1. Results

A weighted total of 54,978 concussions were analyzed between 2012 and 2021. The average weighted age of our cohort was

13.1 years at the time of injury, with 54.1% (n = 29,761) of concussions occurring in males (Fig. 1, Table 1). The national estimated incidence of concussion injuries decreased non-significantly over the study period (slope estimate = -311 concussions/year, r = -0.625, p-value = 0.054), and after removing 2020 numbers due to COVID (slope esti- mate = -178 concussions/year, r = -0.548, p-value = 0.13) (Table 1).

    1. Concussions by contact type

A review of narrative classifications showcased that the majority of weighted national estimate concussions were due to head-to-ball inju- ries (n = 34,650; 63.0%), followed by head-to-player (n = 8501; 15.5%), head-to-surface (n = 5347; 9.7%), and head-to-bat (n = 5089; 9.3%). The unknown category constituted 2.5% (n = 1391) of narratives.

Head-to-ball: The incidence of head-to-ball concussion injuries decreased non-significantly over the study period (slope estimate =

-200 concussions/year, r = -0.613, p-value = 0.06), and after remov-

ing 2020 numbers due to COVID (slope estimate = -110 concussions/ year, r = -0.531, p-value = 0.14).

Head-to-player: The incidence of head-to-player concussion injuries remained steady over the study period (slope estimate = -12 concus- sions/year, r = -0.093, p-value = 0.80), and after removing 2020 numbers due to COVID (slope estimate = 21 concussions/year, r = 0.190, p-value = 0.63).

Head-to-bat: The incidence of head-to-bat concussion injuries remained steady over the study period (slope estimate = -18 concus- sions/year, r = -0.484, p-value = 0.16), and after removing 2020 numbers due to COVID (slope estimate = -15 concussions/year, r =

-0.384, p-value = 0.31).

Image of Fig. 1

Fig. 1. Baseball and softball concussion incidence by age.

Table 1

Breakdown of injuries by year.

Table 2

Concussion incidence by age group and contact type.

Year

Total

Males

Females

Narrative

Ages 4-8

Ages 9-13

Ages 14-17

2021

4958

2457

2501

Head-to-ball

2104 (51.2%)

15,581 (67.3%)

16,965 (61.2%)

2020

2055

1318

737

Head-to-player

204 (5.0%)

2897 (12.5%)

5400 (19.5%)

2019

4694

2296

2398

Head-to-bat

1514 (36.8%)

2225 (9.6%)

1349 (4.9%)

2018

5252

2340

2912

Head-to-surface

259 (6.3%)

1817 (7.8%)

3271 (11.8%)

2017

6216

3521

2695

Unknown

31 (0.8%)

629 (2.7%)

732 (2.6%)

2016

5963

3393

2570

Total

4112

23,149

27,717

2015

7599

4679

2919

2014

6734

3341

3393

2013

5120

3179

1941

surroundings, which increases with age. As players get older, they get

2012

Average

6389

5498

3238

2976

3151

2522

faster and stronger, which can explain why there is an uptick in head-

to-player and head-to-surface mechanisms between those aged 9-13

Head-to-surface: The incidence of head-to-surface concussion injuries decreased non-significantly over the study period (slope esti- mate = -67 concussions/year, r = -0.626, p-value = 0.053), and after removing 2020 numbers due to COVID (slope estimate = -60 concussions/year, r = -0.554, p-value = 0.12) (Fig. 2).

    1. Contact type classified by age

On sub-analysis, individuals were grouped into 3 age brackets: 4-8, 9-13, and 14-17 years. The most common cause of concussions in children of all ages was head-to-ball. The percent incidence of head- to-player and head-to-surface injuries increased throughout each age group, while head-to-bat decreased (Table 2).

  1. Discussion

Overall, the incidence of concussions in pediatric baseball and softball players decreased non-significantly over our 10-year study pe- riod. The most common mechanism of concussions were head-to-ball injuries, and they have been decreasing non-significantly throughout the last decade. Interestingly, a high proportion of concussions occurred in athletes between the ages of 12 and 16. By stratifying concussion mechanisms between 3 age groups, the most common cause of concus- sions in children of all ages was head-to-ball. The incidence of head-to- player and head-to-surface injuries increased throughout each age group, while head-to-bat decreased. A possible explanation for this is that players aged 4-8 are more likely to injure each other swinging a baseball bat due to having less dexterity and awareness of their

and 14-17.

Previous studies have also utilized the NEISS database to assess concussions in the pediatric population. Chatha et al. found that the in- cidence of concussions in youth Soccer players has been increasing be- tween 2008 and 2016, with the most common mechanism of injury being player-to-player contact [12]. Jacobson et al. found that between 2002 and 2012, the total number of concussions increased with age and year in football players [17]. While these studies saw an increase in concussion incidence, our study saw a non-significant decrease. A multitude of factors could result in this finding. One being that both studied a time period of before 2016, which was a time at which concus- sions were not as talked about relatively compared to 2021. Also, by nature of the sport, soccer and football have more player-to-player con- tact than baseball and softball, which have the potential to cause concussions. We found that 63.0% of concussions in our cohort were due to head-to-ball contact, while only 15.5% were due to head-to- player. In a study performed by Tsushima et al. assessing 10,334 athletes in 12 different sports, the overall incidence of concussions among youth athletes was 1250 (12.1%). The sports with the greatest risk of concus- sions were wrestling/martial arts, followed by cheerleading and football [18]. Pfister et al. performed a systematic review, finding that that the three sports with the highest concussion incidence are rugby (4.18 per 1000 AE), hockey (1.20 per 1000 AE), and football (0.53 per 1000 AE) [19]. Our study builds upon these findings by addressing the mechanism of injuries for pediatric baseball and softball players.

Head-to-ball injuries were found to be the most common overall cause of concussions in our study population. Intuitively, it may be as- sumed that helmets decrease the risk of concussions if hit with a base- ball. However, studies have been showcasing that this may not be the

Image of Fig. 2

Fig. 2. Concussion incidence by year and contact type.

case. Sone et al. performed a review, finding that helmeted patients do not have better clinical outcomes or protection against concussions compared to helmeted patients [20]. Alfrey et al. found that helmeted patients involved in bicycle crashes are less likely to sustain serious in- jury, such as a Skull fracture compared to non-helmeted patient, but they do not prevent concussions [21]. Since the majority of concussions in our study were due to head-to-ball injuries, the understanding that helmets likely do not protect against concussions when hit by a baseball needs to be educated more by medical personnel so athletes understand the risks of their sport.

Once an individual sustains a concussion, like any other injury, re- covery is at the forefront of their mind. Plourde et al. evaluated the per- ceptions of recovery duration following concussions in children aged 11-17, finding that those who expected greater symptom persistence had significantly higher emotional distress based on the Strengths and Difficulties Questionnaire (SDQ) and Pediatric Quality of Life Question- naire (PedsQL) [22]. When Division I college football players were sur- veyed, 40% of them strongly believed that they would sustain a concussion and potential health consequence [23]. However, only 1 in 10 predicted dementia, Alzheimer’s disease, or chronic traumatic encephalopathy developing as a result of their concussion [23]. Im- proved education on the effects of concussions should be emphasized more in sports so athletes understand the risks and potential outcomes better. Based on our findings and previous literature on the effective- ness of helmets, they cannot be solely relied upon to decrease the con- cussion incidence in baseball and softball. With head-to-ball injuries constituting majority of concussions, more attention and education would need to be provided on this topic.

    1. Limitations

The present study carries limitations associated with large database analysis. The NEISS database is limited to only emergency department records, which likely underreports the overall concussion incidence as not every individual goes to the hospital following injury. Also, no follow-up information was recorded in the database, so outcomes fol- lowing injury cannot be analyzed. Additionally, the EDs that the NEISS database samples may have been in states that have a higher or lower percentage of their pediatric population playing baseball and softball than the national average. Due to the NEISS database occasionally not having complete information in the narrative section about how a pa- tient was injured, there was an “unknown” category in our study. Lastly, our study was unable to account for the difference in the level of play for each patient.

  1. Conclusion

The incidence of concussions in pediatric baseball and softball athletes has been decreasing non-significantly over our 10-year study period. The most common mechanism of concussions in our study was head-to-ball injuries.

IRB

This project did not require review by the institutional review board.

Financial conflicts of interest

All authors declare that there are no financial conflicts of interest.

CRediT authorship contribution statement

Varag Abed: Writing – original draft, Methodology, Conceptualiza- tion. Gregory S. Hawk: Writing – review & editing, Data curation. Caitlin Conley: Writing – review & editing. Roy Akarakian: Writing –

review & editing, Validation. Austin V. Stone: Writing – review & editing, Supervision, Conceptualization.

Declaration of Competing Interest

All authors declare that there are no conflicts of interest.

References

  1. Mannix R, Meehan 3rd WP, Pascual-Leone A. Sports-related concussions – media, science and policy. Nat Rev Neurol. 2016;12(8):486-90. https://doi.org/10.1038/ nrneurol.2016.99.
  2. Ku C, McKinlay A, GRACE RC, Linden M, McLellan T. An international exploration of the effect of media portrayals of postconcussion management on concussion identi- fication in the general public. J Head Trauma Rehabil. 2020;35(3):218-25. https:// doi.org/10.1097/HTR.0000000000000547.
  3. Bussell CA, Gavett BE. Effects of media sensationalization on cognitive performance and post concussive symptoms. J Int Neuropsychol Soc. 2019;25(1):90-100. https:// doi.org/10.1017/S1355617718000760.
  4. Mack CD, Solomon G, Covassin T, Theodore N, Cardenas J, Sills A. Epidemiology of concussion in the National Football League, 2015-2019. Sports Health. 2021;13(5): 423-30. https://doi.org/10.1177/19417381211011446.
  5. Sabesan VJ, Prey B, Smith R, Lombardo DJ, Borroto WJ, Whaley JD. Concussion rates and effects on player performance in Major League Baseball players. Open Access J Sports Med. 2018;9:253-60. https://doi.org/10.2147/OAJSM.S157433.
  6. Peterson JG, Tjong VK, Terry MA, Saltzman MD, Gryzlo SM, Sheth U. Concussion in- cidence and impact on player performance in Major League Baseball players before and after a standardized concussion protocol. Orthop J Sports Med. 2020;8(4). https://doi.org/10.1177/2325967120913020. 2325967120913020.
  7. Wasserman EB, Abar B, Shah MN, Wasserman D, Bazarian JJ. Concussions are associ- ated with decreased batting performance among Major League Baseball players. Am J Sports Med. 2015;43(5):1127-33. https://doi.org/10.1177/0363546515576130.
  8. Strickland JS, Crandall M, Bevill GR. A retrospective analysis of softball-related head and facial injuries treated in United States Emergency Departments, 2013-2017. Orthop J Sports Med. 2019;7(2). https://doi.org/10.1177/2325967119825660. 2325967119825660.
  9. Gessel LM, Fields SK, Collins CL, Dick RW, Comstock RD. Concussions among United States high school and collegiate athletes. J Athl Train. 2007;42(4):495-503. https:// www.ncbi.nlm.nih.gov/pubmed/18174937.
  10. Manley G, Gardner AJ, Schneider KJ, Guskiewicz KM, Bailes J, Cantu RC, et al. A sys- tematic review of potential long-term effects of sport-related concussion. Br J Sports Med. 2017;51(12):969-77. https://doi.org/10.1136/bjsports-2017-097791.
  11. Tator CH. Concussions and their consequences: current diagnosis, Management and prevention. CMAJ. 2013;185(11):975-9. https://doi.org/10.1503/cmaj.120039.
  12. Chatha K, Pruis T, Peaguda CF, Guo E, Koen S, Malone D, et al. Concussions in soccer: an epidemiological analysis in the pediatric population. Orthop J Sports Med. 2020;8

(10). https://doi.org/10.1177/2325967120951077. 2325967120951077.

  1. Abed V, Hawk GS, Akarakian R, Stone AV. Epidemiological analysis of concussions in youth ice hockey players: a national emergency room database study. Am J Emerg Med. 2023;67:130-4. https://doi.org/10.1016/j.ajem.2023.02.023.
  2. Dragoo JL, Braun HJ. The effect of playing surface on injury rate: a review of the cur- rent literature. Sports Med. 2010;40(11):981-90. https://doi.org/10.2165/ 11535910-000000000-00000.
  3. Moran J, Cheng R, Schneble CA, Mathew JI, Kahan JB, Li D, et al. Epidemiology of sports-related traumatic hip dislocations reported in United States emergency de- partments, 2010-2019. Orthop J Sports Med. 2022;10(5). https://doi.org/10.1177/ 23259671221088009. 23259671221088009.
  4. Fitzgerald HT, Rubin ST, Fitzgerald DA, Rubin BK. Covid-19 and the impact on Young athletes. Paediatr Respir Rev. 2021;39:9-15. https://doi.org/10.1016/j.prrv.2021.04. 005.
  5. Jacobson NA, Buzas D, Morawa LG. Concussions from youth football: results from NEISS hospitals over an 11-year time frame, 2002-2012. Orthop J Sports Med. 2013;1(7). https://doi.org/10.1177/2325967113517860. 2325967113517860.
  6. Tsushima WT, Siu AM, Ahn HJ, Chang BL, Murata NM. Incidence and risk of concus- sions in youth athletes: comparisons of age, sex, Concussion history, sport, and foot- ball position. Arch Clin Neuropsychol. 2019;34(1):60-9. https://doi.org/10.1093/ arclin/acy019.
  7. Pfister T, Pfister K, Hagel B, Ghali WA, Ronksley PE. The incidence of concussion in youth sports: a systematic review and meta-analysis. Br J Sports Med. 2016;50(5): 292-7. https://doi.org/10.1136/bjsports-2015-094978.
  8. Sone JY, Kondziolka D, Huang JH, Samadani U. Helmet efficacy against concussion and traumatic brain injury: a review. J Neurosurg. 2017;126(3):768-81. https:// doi.org/10.3171/2016.2.JNS151972.
  9. Alfrey EJ, Tracy M, Alfrey JR, Carroll M, Aranda-Wikman ED, Arora T, et al. Helmet usage reduces serious head injury without decreasing concussion after bicycle riders crash. J Surg Res. 2021;257:593-6. https://doi.org/10.1016/j.jss.2020.08.009.
  10. Plourde V, Silverberg ND, Cairncross M, Virani S, Brooks BL. Perceptions of symptom duration are associated with emotional distress and functioning in adolescents with protracted concussion recovery. J Pediatr Psychol. 2022;47(8):905-15. https://doi. org/10.1093/jpepsy/jsac020.
  11. Baugh CM, Kroshus E, Kiernan PT, Mendel D, Meehan 3rd WP. Football players’ per- ceptions of future risk of concussion and concussion-related health outcomes. J Neurotrauma. 2017;34(4):790-7. https://doi.org/10.1089/neu.2016.4585.