Zachary Yukio Kerr

Dr. Zachary Yukio Kerr

orcid

Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 September 2015 in The American Journal of Sports Medicine
Verified
Journal Article
Closed access
SZScott L. Zuckerman
Scott L. Zuckerman
ZKZachary Yukio Kerr
Zachary Yukio Kerr
AYAaron Yengo-Kahn
Aaron Yengo-Kahn
EWErin Wasserman
Erin Wasserman
TCTracey Covassin
Tracey Covassin
GSGary S. Solomon
Gary S. Solomon
The epidemiology of sports-related concussion (SRC) among student-athletes has been extensively researched. However, recent data at the collegiate level are limited. To describe the epidemiology of SRC in 25 National Collegiate Athletic Association (NCAA) sports. Descriptive epidemiology study. SRC data from the NCAA Injury Surveillance Program during the 2009-2010 to 2013-2014 academic years were analyzed. Concussion injury rates, rate ratios (RRs), and injury proportion ratios were reported with 95% CIs. National estimates were also calculated to examine linear trends across time. During the study period, 1670 SRCs were reported, representing a national estimate of 10,560 SRCs reported annually. Among the 25 sports, the overall concussion rate was 4.47 per 10,000 athlete-exposures (AEs) (95% CI, 4.25-4.68). Overall, more SRCs occurred in competitions (53.2%). The competition rate (12.81 per 10,000 AEs) was larger than the practice rate (2.57 per 10,000 AEs) (competition vs practice, RR = 4.99; 95% CI, 4.53-5.49). Of all SRCs, 9.0% were recurrent. Most SRCs occurred from player contact (68.0%). The largest concussion rates were in men’s wrestling (10.92 per 10,000 AEs; 95% CI, 8.62-13.23), men’s ice hockey (7.91 per 10,000 AEs; 95% CI, 6.87-8.95), women’s ice hockey (7.50 per 10,000 AEs; 95% CI, 5.91-9.10), and men’s football (6.71 per 10,000 AEs; 95% CI, 6.17-7.24). However, men’s football had the largest annual estimate of reported SRCs (n = 3417), followed by women’s soccer (n = 1113) and women’s basketball (n = 998). Among all SRCs, a linear trend did not exist in national estimates across time (P = .17). However, increases were found within specific sports, such as men’s football, women’s ice hockey, and men’s lacrosse. The estimated number of nationally reported SRCs has increased within specific sports. However, it is unknown whether these increases are attributable to increased reporting or frequency of concussions. Many sports report more SRCs in practice than in competition, although competition rates are higher. Men’s wrestling and men’s and women’s ice hockey have the highest reported concussion rates. Men’s football had the highest annual national estimate of reported SRCs, although the annual participation count was also the highest. Future research should continue to longitudinally examine SRC incidence while considering differences by sex, division, and level of competition.

16 September 2020 in Children
Verified
Journal Article
Open access
PDF file
LBLauren Bates
Lauren Bates
GZGabriel Zieff
Gabriel Zieff
KSKathleen Stanford
Kathleen Stanford
Justin B. MooreJustin B. Moore
Justin B. Moore
ZKZachary Yukio Kerr
Zachary Yukio Kerr
Lee StonerLee Stoner
Lee Stoner
In the wake of the COVID-19 pandemic, social restrictions to contain the spread of the virus have disrupted behaviors across the 24-h day including physical activity, sedentary behavior, and sleep among children (5–12 years old) and adolescents (13–17 years old). Preliminary evidence reports significant decreases in physical activity, increases in sedentary behavior, and disrupted sleep schedules/sleep quality in children and adolescents. This commentary discusses the impact of COVID-19-related restrictions on behaviors across the 24-h day in children and adolescents. Furthermore, we suggest recommendations through the lens of a socio-ecological model to provide strategies for lasting behavior change to insure the health and well-being of children and adolescents during the COVID-19 pandemic.

24 August 2012 in The American Journal of Sports Medicine
Verified
Journal Article
Closed access
PDF file
ZKZachary Yukio Kerr
Zachary Yukio Kerr
SMStephen W. Marshall
Stephen W. Marshall
HHHerndon P. Harding
Herndon P. Harding
KGKevin M. Guskiewicz
Kevin M. Guskiewicz
Background: Concussions may accelerate the progression to long-term mental health outcomes such as depression in athletes. Purpose: To prospectively determine the effects of recurrent concussions on the clinical diagnosis of depression in a group of retired football players. Study Design: Cohort study; Level of evidence, 2. Methods: Members of the National Football League Retired Players Association responded to a baseline General Health Survey (GHS) in 2001. They also completed a follow-up survey in 2010. Both surveys asked about demographic information, number of concussions sustained during their professional football career, physical/mental health, and prevalence of diagnosed medical conditions. A physical component summary (Short Form 36 Measurement Model for Functional Assessment of Health and Well-Being [SF-36 PCS]) was calculated from responses for physical health. The main exposure, the history of concussions during the professional playing career (self-report recalled in 2010), was stratified into 5 categories: 0 (referent), 1 to 2, 3 to 4, 5 to 9, and 10+ concussions. The main outcome was a clinical diagnosis of depression between the baseline and follow-up GHS. Classic tabular methods computed crude risk ratios. Binomial regression with a Poisson residual and robust variance estimation to stabilize the fitting algorithm estimated adjusted risk ratios. χ 2 analyses identified associations and trends between concussion history and the 9-year risk of a depression diagnosis. Results: Of the 1044 respondents with complete data from the baseline and follow-up GHS, 106 (10.2%) reported being clinically diagnosed as depressed between the baseline and follow-up GHS. Approximately 65% of all respondents self-reported sustaining at least 1 concussion during their professional careers. The 9-year risk of a depression diagnosis increased with an increasing number of self-reported concussions, ranging from 3.0% in the “no concussions” group to 26.8% in the “10+” group (linear trend: P < .001). A strong dose-response relationship was observed even after controlling for confounders (years retired from professional football and 2001 SF-36 PCS). Retired athletes with a depression diagnosis also had a lower SF-36 PCS before diagnosis. The association between concussions and depression was independent of the relationship between decreased physical health and depression. Conclusion: Professional football players self-reporting concussions are at greater risk for having depressive episodes later in life compared with those retired players self-reporting no concussions.

1 August 2014 in Journal of Athletic Training
Verified
Journal Article
Closed access
ZKZachary Yukio Kerr
Zachary Yukio Kerr
TDThomas P. Dompier
Thomas P. Dompier
ESErin M. Snook
Erin M. Snook
SMStephen W. Marshall
Stephen W. Marshall
DKDavid Klossner
David Klossner
JCJill Corlette
Jill Corlette
Background: Since 1982, the National Collegiate Athletic Association has used the Injury Surveillance System (ISS) to collect injury and athlete-exposure data from a representative sample of collegiate institutions and sports. At the start of the 2004–2005 academic year, a Web-based ISS replaced the paper-based platform previously used for reporting injuries and exposures. Objective: To describe the methods of the Web-based National Collegiate Athletic Association ISS for data collection as implemented from the 2004–2005 to 2013–2014 academic years. Description: The Web-based ISS monitored National Collegiate Athletic Association–sanctioned practices and competitions, the number of participating student–athletes, and time-loss injuries during the preseason, regular season, and postseason in 25 collegiate sports. Starting in the 2009–2010 academic year, non–time-loss injuries were also tracked. Efforts were made to better integrate ISS data collection into the workflow of collegiate athletic trainers. Data for the 2004–2005 to 2013–2014 academic years are available to researchers through a standardized application process available at the Datalys Center Web site. Conclusions: As of February 2014, more than 1 dozen data sets have been provided to researchers. The Datalys Center encourages applications for access to the data.

18 November 2015 in The American Journal of Sports Medicine
Verified
Journal Article
Open access
PDF file
ZKZachary Yukio Kerr
Zachary Yukio Kerr
JRJohna K. Register-Mihalik
Johna K. Register-Mihalik
EKEmily Kroshus
Emily Kroshus
CBChristine M. Baugh
Christine M. Baugh
SMStephen W. Marshall
Stephen W. Marshall
Background: Previous studies examining nondisclosure among athletes in various settings have found substantial proportions of athletes with undisclosed concussions. Substantial gaps exist in our understanding of the factors influencing athletes’ disclosure of sports-related concussions. Purpose: To examine the prevalence of, and factors associated with, nondisclosure of recalled concussions in former collegiate athletes. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Former collegiate athletes (N = 797) completed an online questionnaire. Respondents recalled self-identified sports-related concussions (SISRCs) that they sustained while playing sports in high school, college, or professionally, and whether they disclosed these SISRCs to others. Respondents also recalled motivations for nondisclosure. The prevalence of nondisclosure was calculated among those who recalled SISRCs. Multivariate binomial regression estimated adjusted prevalence ratios (PRs) with 95% CIs, controlling for sex, level of contact in sports, and year the athletes began playing collegiate sports. Results: A total of 214 respondents (26.9%) reported sustaining at least 1 SISRC. Of these, 71 (33.2%) reported not disclosing at least 1 SISRC. Former football athletes were most likely to report nondisclosure (68.3% of those recalling SISRCs); female athletes who participated in low/noncontact sports were the least likely to report nondisclosure (11.1% of those recalling SISRC). The prevalence of nondisclosure was higher among men than women in the univariate analysis (PR, 2.88; 95% CI, 1.62-5.14), multivariate analysis (PR, 2.11; 95% CI, 1.13-3.96), and multivariate analysis excluding former football athletes (PR, 2.11; 95% CI, 1.12-3.94). The most commonly reported motivations were as follows: did not want to leave the game/practice (78.9%), did not want to let the team down (71.8%), did not know it was a concussion (70.4%), and did not think it was serious enough (70.4%). Conclusion: Consistent with previous studies, a substantial proportion of former athletes recalled SISRCs that were not disclosed. Male athletes were less likely to disclose all of their SISRCs than female athletes.

16 April 2014 in Brain Injury
Verified
Journal Article
Closed access
ZKZachary Yukio Kerr
Zachary Yukio Kerr
JRJohna K. Register-Mihalik
Johna K. Register-Mihalik
SMStephen W. Marshall
Stephen W. Marshall
KEKelly R. Evenson
Kelly R. Evenson
JMJason Peter Mihalik
Jason Peter Mihalik
KGKevin M. Guskiewicz
Kevin M. Guskiewicz
To summarize the factors associated with athletes' disclosure-and non-disclosure-of sports-related concussion and concussion symptoms within the context of the socio-ecological framework and to identify research gaps in the current literature. Searches using electronic databases identified studies written in English, published through October 2013 and addressing some aspect of disclosure of concussion and concussion symptoms. The literature search aimed to be comprehensive and inclusive of all previous contributions. Of the 30 identified studies, most originated from the US (n = 19) and sampled athletes (n = 21) and coaches (n = 10) from high school (n = 11) and college levels (n = 9). The identified reasons for non-disclosure were organized into four levels using the socio-ecological framework: intra-personal (e.g. lack of knowledge; internal pressure; sex; concussion history; n = 20 studies); inter-personal (e.g. others' knowledge/attitudes; external pressure; external support; n = 15 studies); environment (e.g. access to concussion prevention materials; sports culture; n = 4 studies); and policy (e.g. concussion-related legislation; n = 3 studies). No study examined all four levels. Research gaps exist concerning factors influencing athletes' disclosure of sports-related concussions and concussion symptoms. Notably, researchers have focused on intra-personal and inter-personal levels, placing less emphasis on the environment and policy levels.