Letters COMMENT & RESPONSE
Concerns About Concussion Rates in Female Youth Soccer To the Editor As the authors of a recent study of concussion in youth football (aged 8-12 years), we know all too well the challenges of conducting research in this population.1 O’Kane and colleagues2 are to be commended for conducting research on concussion in youth female soccer players in a recent issue of JAMA Pediatrics, as we know little about this at-risk population and, in particular, girls. However, we have several concerns regarding the reported results and the nature of the methods used in this study. One of our primary concerns is the high incidence rate of concussions (1.2 per 1000 athletic exposures) and the finding that more than 30% of all concussions involved heading the soccer ball. The incidence rate reported in the current study is 3 to 4 times higher than those reported at high school and collegiate levels.3 We believe that the high incidence rate in the current study was owing in part to the definition of concussion used in the current study, which was based on selfreported symptoms. The authors acknowledged that the median time to recovery in the current study was 4 days, which is far below reported recovery times for adolescent athletes.4 Moreover, 7 of the concussions (12%) involved symptoms lasting less than a day, suggesting they were not concussions. The authors asked parents, coaches, and physicians, physician assistants, and athletic trainers to identify concussions using an Internet injury-surveillance system that was validated with musculoskeletal injuries, not concussions. Of the total 59 concussions in the current study, 33 (56%) were never diagnosed by a physician, physician assistant, or athletic trainer. Only 20 of 59 concussions (34%) were medically diagnosed. This would result in an incidence rate of 0.46 per 1000 athletic exposures, which is more in line with previous research. As a result of the definition of concussion, reliance on self-reported symptoms, and surveillance methods, we believe that the concussion rate reported by O’Kane and colleagues is inflated. With regard to heading the soccer ball as a mechanism of injury, it is unclear how many concussions in the current study were the result of intentional heading of the ball. Based on previous research,5 it is unlikely that intentional heading of the ball resulted in concussions; rather it is more likely that being struck by a ball or inadvertently contacting another player’s head during heading resulted in these injuries. We believe that results regarding soccer heading as a mechanism of injury are unclear and potentially misleading. Anthony P. Kontos, PhD R. J. Elbin, PhD Tracey Covassin, PhD jamapediatrics.com
Author Affiliations: UPMC Sports Medicine Concussion Program, Department of Orthopedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylavania (Kontos); Department of Health, Human Performance, and Recreation, University of Arkansas, Fayetteville (Elbin); Department of Kinesiology, Michigan State University, Lansing (Covassin). Corresponding Author: Anthony P. Kontos, PhD, UPMC Sports Medicine Concussion Program, Department of Orthopedic Surgery, University of Pittsburgh, 3200 S Water St, Pittsburgh, PA 15203 ([email protected]). Conflict of Interest Disclosures: None reported. 1. Kontos AP, Elbin RJ, Fazio-Sumrock VC, et al. Incidence of sports-related concussion among youth football players aged 8-12 years. J Pediatr. 2013;163 (3):717-720. 2. O’Kane JW, Spieker A, Levy MR, Neradilek M, Polissar NL, Schiff MA. Concussion among female middle-school soccer players. JAMA Pediatr. 2014; 168(3):258-264. 3. Marar M, McIlvain NM, Fields SK, Comstock RD. Epidemiology of concussions among United States high school athletes in 20 sports. Am J Sports Med. 2012; 40(4):747-755. 4. Meehan WP III, d’Hemecourt P, Collins CL, Comstock RD. Assessment and management of sport-related concussions in United States high schools. Am J Sports Med. 2011;39(11):2304-2310. 5. Schmitt DM, Hertel J, Evans TA, Olmsted LC, Putukian M. Effect of an acute bout of soccer heading on postural control and self-reported concussion symptoms. Int J Sports Med. 2004;25(5):326-331.
To the Editor We are writing in response to the excellent article published in a recent issue of JAMA Pediatrics by O’Kane et al.1 The authors’ concern for the risk of concussion among middleschool–aged female soccer players matches that from our own clinical experience and is an important addition to sports medicine literature. The article provides strong support for a relatively high incidence rate of concussion among this population and recognizes a worrisome reluctance to seek medical attention in many injured players. We would like to express our caution at how the specific act of heading the ball has been attributed risk in the O’Kane et al article. While the research was well planned and expertly conducted, we feel methods were not designed to determine which specific characteristic of heading most influences athletes’ risk for concussion. In particular, we feel the statements, “heading the ball accounts for 30.5% of concussions” and “heading the ball is a frequent precipitating event” in the abstract are misleading and not supported by the data presented. Concussions in soccer certainly can occur during the act of heading; however, injury most often results from head-tohead, elbow-to-head, or head-to-ground contact.2 Although inadvertent head-to-ball contact once a drilled ball unexpectedly hits a player’s head can certainly result in injury,3 voluntary heading of the ball seldom causes concussion. An Internetbased survey completed by parents is unlikely to provide differentiation between these events associated with heading. Previous studies have required video footage or prospective direct visualization of heading events by investigators.4 JAMA Pediatrics October 2014 Volume 168, Number 10
Copyright 2014 American Medical Association. All rights reserved.
Downloaded From: http://archpedi.jamanetwork.com/ by a Nanyang Technological University User on 05/20/2015
967
Letters
Risk factors such as neck strength, anticipation of contact, and heading technique are postulated by O’Kane et al as potential risk factors for concussions that occur during heading. We wholeheartedly agree and believe there are studies to support such conclusions.5 Further research is warranted with the proviso that events inherent to heading in soccer can be differentiated and that the act of purposefully heading the ball is not inappropriately deemed dangerous. Hamish A. Kerr, MD, MSc Jeffrey M. Mjaanes, MD Author Affiliations: Albany Medical College, Latham, New York (Kerr); Rush University Medical Center, Chicago, Illinois (Mjaanes). Corresponding Author: Hamish A. Kerr, MD, MSc, Albany Medical College, 724 Watervliet-Shaker Rd, Latham, NY 12110 ([email protected]). Conflict of Interest Disclosures: None reported. 1. O’Kane JW, Spieker A, Levy MR, Neradilek M, Polissar NL, Schiff MA. Concussion among female middle-school soccer players. JAMA Pediatr. 2014; 168(3):258-264. 2. Niedfeldt MW. Head injuries, heading, and the use of headgear in soccer. Curr Sports Med Rep. 2011;10(6):324-329. 3. Koutures CG, Gregory AJ; American Academy of Pediatrics; Council on Sports Medicine and Fitness. Injuries in youth soccer. Pediatrics. 2010;125(2):410-414. 4. Delaney JS, Al-Kashmiri A, Correa JA. Mechanisms of injury for concussions in university football, ice hockey, and soccer. Clin J Sport Med. 2014;24(3):233-237. 5. Dezman ZD, Ledet EH, Kerr HA. Neck strength imbalance correlates with increased head acceleration in soccer heading. Sports Health. 2013;5(4):320-326.
In Reply Thank you for your letters and interest in our study. We appreciate concerns that our concussion incidence rate was inflated but we believe it represents the best estimate in our study population. We currently lack an objective tool to confirm or rule out concussion; symptom checklists are a primary means by which concussion is diagnosed.1 While it is true that these symptoms are short-lived in many of our participants, the current clinical definition of concussion2 does not stipulate symptoms must be present for a minimum amount of time. In several studies, the primary finding has been that a significant proportion of athletes do not report their symptoms.3,4 Clearly, the greater the reporting burden on the athlete and the greater the amount of time between the injury and the assessment of symptoms, the lower the concussion incidence rate. Whether or not transient neurocognitive symptoms that resolve quickly are of relevance is an unanswered question, but the consensus is that we would like all athletes to report their symptoms. For clarification, our Internet injury-surveillance system did not involve reporting by coaches or medical professionals but only the participants reporting via their parents. We appreciate the observation that if we considered only the medically diagnosed concussions our incidence rates would be similar to other studies. This is exactly our point, that many athletes do not report concussion symptoms to their coaches or athletic trainers, and as a result, the incidence rates in the literature that rely on athlete reporting is artificially low. We also suspect other physicians, physician assistants, and athletic trainers misdiagnosed concussions in our study, highlighting the need for additional training in recognizing and reporting concussions. Our partici968
pants who saw a physician, physician assistant, or athletic trainer but did not receive a concussion diagnosis had an average of 3.5 concussion symptoms and had symptoms lasting an average of 7.5 days. Regarding the finding that 30.5% of the concussions occurred in the act of heading the ball, we interviewed our concussed participants and asked what players were doing when their injuries occurred. We do not believe this finding implies that heading the ball causes brain injury; this is an area of active debate. A recent study of male and female youth soccer players found that varied heading exposure did not result in differences in neurocognitive performance or concussion symptoms,5 while a study of college players found impaired postural control following bouts of heading.6 Thirty percent of our participants were trying to head the ball when they were injured. They may have missed hitting the ball or in the act of heading they may have had contact with another player’s head, but the controllable and modifiable activity in nearly onethird of the injuries is the attempt to head the ball. The injuries also occurred predominantly in game situations, so it is our opinion that heading can be taught safely in training at younger ages; modifying or limiting heading in games until kids are older offers an opportunity to decrease the risk of concussion. John W. O’Kane, MD Melissa A. Schiff, MD, MPH Author Affiliations: UW Sports Medicine Clinic, Department of Family Medicine, University of Washington, Seattle (O’Kane); Harborview Injury Prevention and Research Center, Department of Epidemiology, University of Washington, Seattle (Schiff). Corresponding Author: John W. O’Kane, MD, UW Sports Medicine Clinic, 3800 Montlake Blvd NE, Seattle, WA 98195 ([email protected]). Conflict of Interest Disclosures: None reported. 1. Gioia GA, Schneider JC, Vaughan CG, Isquith PK. Which symptom assessments and approaches are uniquely appropriate for pediatric concussion? Br J Sports Med. 2009;43(suppl 1):i13-i22. 2. McCrory P, Meeuwisse WH, Aubry M, et al. Consensus statement on concussion in sport: the 4th International Conference on Concussion in Sport held in Zurich: November 2012. Br J Sports Med. 2013;47(5):250-258. 3. Chrisman SP, Quitiquit C, Rivara FP. Qualitative study of barriers to concussive symptom reporting in high school athletics. J Adolesc Health. 2013;52(3):330-335, e3. 4. Bramley H, Patrick K, Lehman E, Silvis M. High school soccer players with concussion education are more likely to notify their coach of a suspected concussion. Clin Pediatr (Phila). 2012;51(4):332-336. 5. Kontos AP, Dolese A, Elbin RJ, Covassin T, Warren BL. Relationship of soccer heading to computerized neurocognitive performance and symptoms among female and male youth soccer players. Brain Inj. 2011;25(12):1234-1241. 6. Haran FJ, Tierney R, Wright WG, Keshner E, Silter M. Acute changes in postural control after soccer heading. Int J Sports Med. 2013;34(4):350-354.
Infants and Interactive Media Use To the Editor I read the Viewpoint recently published in JAMA Pediatrics by Dr Christakis1 regarding interactive media use in children younger than 2 years of age with great interest and agreement. In addition, I would urge that the definition of interactive media be broadened beyond “interactive applications currently designed for children”1 to incorporate videoconferencing programs such as Skype and FaceTime. These programs are used by even the youngest children to engage in
JAMA Pediatrics October 2014 Volume 168, Number 10
Copyright 2014 American Medical Association. All rights reserved.
Downloaded From: http://archpedi.jamanetwork.com/ by a Nanyang Technological University User on 05/20/2015
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Concerns About Concussion Rates in Female Youth Soccer To the Editor As the authors of a recent study of concussion in youth football (aged 8-12 years), we know all too well the challenges of conducting research in this population.1 O’Kane and colleagues2 are to be commended for conducting research on concussion in youth female soccer players in a recent issue of JAMA Pediatrics, as we know little about this at-risk population and, in particular, girls. However, we have several concerns regarding the reported results and the nature of the methods used in this study. One of our primary concerns is the high incidence rate of concussions (1.2 per 1000 athletic exposures) and the finding that more than 30% of all concussions involved heading the soccer ball. The incidence rate reported in the current study is 3 to 4 times higher than those reported at high school and collegiate levels.3 We believe that the high incidence rate in the current study was owing in part to the definition of concussion used in the current study, which was based on selfreported symptoms. The authors acknowledged that the median time to recovery in the current study was 4 days, which is far below reported recovery times for adolescent athletes.4 Moreover, 7 of the concussions (12%) involved symptoms lasting less than a day, suggesting they were not concussions. The authors asked parents, coaches, and physicians, physician assistants, and athletic trainers to identify concussions using an Internet injury-surveillance system that was validated with musculoskeletal injuries, not concussions. Of the total 59 concussions in the current study, 33 (56%) were never diagnosed by a physician, physician assistant, or athletic trainer. Only 20 of 59 concussions (34%) were medically diagnosed. This would result in an incidence rate of 0.46 per 1000 athletic exposures, which is more in line with previous research. As a result of the definition of concussion, reliance on self-reported symptoms, and surveillance methods, we believe that the concussion rate reported by O’Kane and colleagues is inflated. With regard to heading the soccer ball as a mechanism of injury, it is unclear how many concussions in the current study were the result of intentional heading of the ball. Based on previous research,5 it is unlikely that intentional heading of the ball resulted in concussions; rather it is more likely that being struck by a ball or inadvertently contacting another player’s head during heading resulted in these injuries. We believe that results regarding soccer heading as a mechanism of injury are unclear and potentially misleading. Anthony P. Kontos, PhD R. J. Elbin, PhD Tracey Covassin, PhD jamapediatrics.com
Author Affiliations: UPMC Sports Medicine Concussion Program, Department of Orthopedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylavania (Kontos); Department of Health, Human Performance, and Recreation, University of Arkansas, Fayetteville (Elbin); Department of Kinesiology, Michigan State University, Lansing (Covassin). Corresponding Author: Anthony P. Kontos, PhD, UPMC Sports Medicine Concussion Program, Department of Orthopedic Surgery, University of Pittsburgh, 3200 S Water St, Pittsburgh, PA 15203 ([email protected]). Conflict of Interest Disclosures: None reported. 1. Kontos AP, Elbin RJ, Fazio-Sumrock VC, et al. Incidence of sports-related concussion among youth football players aged 8-12 years. J Pediatr. 2013;163 (3):717-720. 2. O’Kane JW, Spieker A, Levy MR, Neradilek M, Polissar NL, Schiff MA. Concussion among female middle-school soccer players. JAMA Pediatr. 2014; 168(3):258-264. 3. Marar M, McIlvain NM, Fields SK, Comstock RD. Epidemiology of concussions among United States high school athletes in 20 sports. Am J Sports Med. 2012; 40(4):747-755. 4. Meehan WP III, d’Hemecourt P, Collins CL, Comstock RD. Assessment and management of sport-related concussions in United States high schools. Am J Sports Med. 2011;39(11):2304-2310. 5. Schmitt DM, Hertel J, Evans TA, Olmsted LC, Putukian M. Effect of an acute bout of soccer heading on postural control and self-reported concussion symptoms. Int J Sports Med. 2004;25(5):326-331.
To the Editor We are writing in response to the excellent article published in a recent issue of JAMA Pediatrics by O’Kane et al.1 The authors’ concern for the risk of concussion among middleschool–aged female soccer players matches that from our own clinical experience and is an important addition to sports medicine literature. The article provides strong support for a relatively high incidence rate of concussion among this population and recognizes a worrisome reluctance to seek medical attention in many injured players. We would like to express our caution at how the specific act of heading the ball has been attributed risk in the O’Kane et al article. While the research was well planned and expertly conducted, we feel methods were not designed to determine which specific characteristic of heading most influences athletes’ risk for concussion. In particular, we feel the statements, “heading the ball accounts for 30.5% of concussions” and “heading the ball is a frequent precipitating event” in the abstract are misleading and not supported by the data presented. Concussions in soccer certainly can occur during the act of heading; however, injury most often results from head-tohead, elbow-to-head, or head-to-ground contact.2 Although inadvertent head-to-ball contact once a drilled ball unexpectedly hits a player’s head can certainly result in injury,3 voluntary heading of the ball seldom causes concussion. An Internetbased survey completed by parents is unlikely to provide differentiation between these events associated with heading. Previous studies have required video footage or prospective direct visualization of heading events by investigators.4 JAMA Pediatrics October 2014 Volume 168, Number 10
Copyright 2014 American Medical Association. All rights reserved.
Downloaded From: http://archpedi.jamanetwork.com/ by a Nanyang Technological University User on 05/20/2015
967
Letters
Risk factors such as neck strength, anticipation of contact, and heading technique are postulated by O’Kane et al as potential risk factors for concussions that occur during heading. We wholeheartedly agree and believe there are studies to support such conclusions.5 Further research is warranted with the proviso that events inherent to heading in soccer can be differentiated and that the act of purposefully heading the ball is not inappropriately deemed dangerous. Hamish A. Kerr, MD, MSc Jeffrey M. Mjaanes, MD Author Affiliations: Albany Medical College, Latham, New York (Kerr); Rush University Medical Center, Chicago, Illinois (Mjaanes). Corresponding Author: Hamish A. Kerr, MD, MSc, Albany Medical College, 724 Watervliet-Shaker Rd, Latham, NY 12110 ([email protected]). Conflict of Interest Disclosures: None reported. 1. O’Kane JW, Spieker A, Levy MR, Neradilek M, Polissar NL, Schiff MA. Concussion among female middle-school soccer players. JAMA Pediatr. 2014; 168(3):258-264. 2. Niedfeldt MW. Head injuries, heading, and the use of headgear in soccer. Curr Sports Med Rep. 2011;10(6):324-329. 3. Koutures CG, Gregory AJ; American Academy of Pediatrics; Council on Sports Medicine and Fitness. Injuries in youth soccer. Pediatrics. 2010;125(2):410-414. 4. Delaney JS, Al-Kashmiri A, Correa JA. Mechanisms of injury for concussions in university football, ice hockey, and soccer. Clin J Sport Med. 2014;24(3):233-237. 5. Dezman ZD, Ledet EH, Kerr HA. Neck strength imbalance correlates with increased head acceleration in soccer heading. Sports Health. 2013;5(4):320-326.
In Reply Thank you for your letters and interest in our study. We appreciate concerns that our concussion incidence rate was inflated but we believe it represents the best estimate in our study population. We currently lack an objective tool to confirm or rule out concussion; symptom checklists are a primary means by which concussion is diagnosed.1 While it is true that these symptoms are short-lived in many of our participants, the current clinical definition of concussion2 does not stipulate symptoms must be present for a minimum amount of time. In several studies, the primary finding has been that a significant proportion of athletes do not report their symptoms.3,4 Clearly, the greater the reporting burden on the athlete and the greater the amount of time between the injury and the assessment of symptoms, the lower the concussion incidence rate. Whether or not transient neurocognitive symptoms that resolve quickly are of relevance is an unanswered question, but the consensus is that we would like all athletes to report their symptoms. For clarification, our Internet injury-surveillance system did not involve reporting by coaches or medical professionals but only the participants reporting via their parents. We appreciate the observation that if we considered only the medically diagnosed concussions our incidence rates would be similar to other studies. This is exactly our point, that many athletes do not report concussion symptoms to their coaches or athletic trainers, and as a result, the incidence rates in the literature that rely on athlete reporting is artificially low. We also suspect other physicians, physician assistants, and athletic trainers misdiagnosed concussions in our study, highlighting the need for additional training in recognizing and reporting concussions. Our partici968
pants who saw a physician, physician assistant, or athletic trainer but did not receive a concussion diagnosis had an average of 3.5 concussion symptoms and had symptoms lasting an average of 7.5 days. Regarding the finding that 30.5% of the concussions occurred in the act of heading the ball, we interviewed our concussed participants and asked what players were doing when their injuries occurred. We do not believe this finding implies that heading the ball causes brain injury; this is an area of active debate. A recent study of male and female youth soccer players found that varied heading exposure did not result in differences in neurocognitive performance or concussion symptoms,5 while a study of college players found impaired postural control following bouts of heading.6 Thirty percent of our participants were trying to head the ball when they were injured. They may have missed hitting the ball or in the act of heading they may have had contact with another player’s head, but the controllable and modifiable activity in nearly onethird of the injuries is the attempt to head the ball. The injuries also occurred predominantly in game situations, so it is our opinion that heading can be taught safely in training at younger ages; modifying or limiting heading in games until kids are older offers an opportunity to decrease the risk of concussion. John W. O’Kane, MD Melissa A. Schiff, MD, MPH Author Affiliations: UW Sports Medicine Clinic, Department of Family Medicine, University of Washington, Seattle (O’Kane); Harborview Injury Prevention and Research Center, Department of Epidemiology, University of Washington, Seattle (Schiff). Corresponding Author: John W. O’Kane, MD, UW Sports Medicine Clinic, 3800 Montlake Blvd NE, Seattle, WA 98195 ([email protected]). Conflict of Interest Disclosures: None reported. 1. Gioia GA, Schneider JC, Vaughan CG, Isquith PK. Which symptom assessments and approaches are uniquely appropriate for pediatric concussion? Br J Sports Med. 2009;43(suppl 1):i13-i22. 2. McCrory P, Meeuwisse WH, Aubry M, et al. Consensus statement on concussion in sport: the 4th International Conference on Concussion in Sport held in Zurich: November 2012. Br J Sports Med. 2013;47(5):250-258. 3. Chrisman SP, Quitiquit C, Rivara FP. Qualitative study of barriers to concussive symptom reporting in high school athletics. J Adolesc Health. 2013;52(3):330-335, e3. 4. Bramley H, Patrick K, Lehman E, Silvis M. High school soccer players with concussion education are more likely to notify their coach of a suspected concussion. Clin Pediatr (Phila). 2012;51(4):332-336. 5. Kontos AP, Dolese A, Elbin RJ, Covassin T, Warren BL. Relationship of soccer heading to computerized neurocognitive performance and symptoms among female and male youth soccer players. Brain Inj. 2011;25(12):1234-1241. 6. Haran FJ, Tierney R, Wright WG, Keshner E, Silter M. Acute changes in postural control after soccer heading. Int J Sports Med. 2013;34(4):350-354.
Infants and Interactive Media Use To the Editor I read the Viewpoint recently published in JAMA Pediatrics by Dr Christakis1 regarding interactive media use in children younger than 2 years of age with great interest and agreement. In addition, I would urge that the definition of interactive media be broadened beyond “interactive applications currently designed for children”1 to incorporate videoconferencing programs such as Skype and FaceTime. These programs are used by even the youngest children to engage in
JAMA Pediatrics October 2014 Volume 168, Number 10
Copyright 2014 American Medical Association. All rights reserved.
Downloaded From: http://archpedi.jamanetwork.com/ by a Nanyang Technological University User on 05/20/2015
jamapediatrics.com
