title: Epidemiologic Measures for Quantifying the Incidence of Concussion in National Collegiate Athletic Association Sports.
abstract: BACKGROUND
  Injury rates compare the relative frequency of sport-related concussions across groups. However, they may not be intuitive to policy makers, parents, or coaches in understanding the likelihood of concussion.
  
  
  OBJECTIVE
  To describe 4 measures of incidence (athlete-based rate, athlete-based risk, team-based rate, and team-based risk) during the 2011-2012 through 2014-2015 academic years.
  
  
  METHODS
  Descriptive epidemiology study.
  
  
  METHODS
  Aggregate injury and exposure data collected from the National Collegiate Athletic Association Injury Surveillance Program in 13 sports (men's baseball, basketball, football, ice hockey, lacrosse, soccer, and wrestling and women's basketball, ice hockey, lacrosse, soccer, softball, and volleyball).
  
  
  METHODS
  Collegiate student-athletes.
  
  
  METHODS
  Sport-related concussion data from the National Collegiate Athletic Association Injury Surveillance Program during the 2011-2012 through 2014-2015 academic years were analyzed. We calculated concussion rates per 1000 athlete-exposures (AEs), concussion risk, average number of concussions per team, and percentage of teams with at least 1 concussion.
  
  
  RESULTS
  During the 2011-2012 through 2014-2015 academic years, 1485 concussions were sustained by 1410 student-athletes across 13 sports. Concussion rates ranged from 0.09/1000 AEs in men's baseball to 0.89/1000 AEs in men's wrestling. Concussion risk ranged from 0.74% in men's baseball to 7.92% in men's wrestling. The average ± SD number of concussions per team ranged from 0.25 ± 0.43 in men's baseball to 5.63 ± 5.36 in men's football. The percentage of teams with a concussion ranged from 24.5% in men's baseball to 80.6% in men's football.
  
  
  CONCLUSIONS
  Although men's wrestling had a higher concussion rate and risk, men's football had the largest average number of concussions per team and the largest percentage of teams with at least 1 concussion. The risk of concussion, average number of concussions per team, and percentage of teams with concussions may be more intuitive measures of incidence for decision makers. Calculating these additional measures is feasible within existing injury surveillance programs, and this method can be applied to other injury types.
authors.affiliation: The Datalys Center for Sports Injury Research and Prevention, Inc, Indianapolis, IN.
authors.forename: Zachary Y
authors.initials: ZY
authors.lastname: Kerr
authors.affiliation: The Datalys Center for Sports Injury Research and Prevention, Inc, Indianapolis, IN.
authors.forename: Karen G
authors.initials: KG
authors.lastname: Roos
authors.affiliation: The Datalys Center for Sports Injury Research and Prevention, Inc, Indianapolis, IN.
authors.forename: Aristarque
authors.initials: A
authors.lastname: Djoko
authors.affiliation: The Datalys Center for Sports Injury Research and Prevention, Inc, Indianapolis, IN.
authors.forename: Sara L
authors.initials: SL
authors.lastname: Dalton
authors.affiliation: School of Kinesiology, University of Michigan, Ann Arbor.
authors.forename: Steven P
authors.initials: SP
authors.lastname: Broglio
authors.affiliation: Department of Epidemiology, University of North Carolina at Chapel Hill.
authors.forename: Stephen W
authors.initials: SW
authors.lastname: Marshall
authors.affiliation: The Datalys Center for Sports Injury Research and Prevention, Inc, Indianapolis, IN.
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Dompier
mesh_terms: D056352:Athletes / Q000706:statistics & numerical data; D001265:Athletic Injuries / Q000453:epidemiology*; D001484:Baseball / Q000293:injuries; D001490:Basketball / Q000293:injuries; D001924:Brain Concussion / Q000453:epidemiology*; D005260:Female; D005538:Football / Q000293:injuries; D006688:Hockey / Q000293:injuries; D006801:Humans; D015994:Incidence; D008297:Male; D015865:Racquet Sports / Q000293:injuries; D012307:Risk Factors; D012916:Soccer / Q000293:injuries; D013334:Students / Q000706:statistics & numerical data; D014481:United States / Q000453:epidemiology; D014495:Universities / Q000706:statistics & numerical data; D014952:Wrestling / Q000293:injuries
keywords: collegiate sports; risk; traumatic brain injury