title: Evaluation of a simple test of reaction time for baseline concussion testing in a population of high school athletes.
abstract: OBJECTIVE
  A common sequela of concussions is impaired reaction time. Computerized neurocognitive tests commonly measure reaction time. A simple clinical test for reaction time has been studied previously in college athletes; whether this test is valid and reliable when assessing younger athletes remains unknown. Our study examines the reliability and validity of this test in a population of high school athletes.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  Two American High Schools.
  
  
  METHODS
  High school athletes (N = 448) participating in American football or soccer during the academic years 2011 to 2012 and 2012 to 2013.
  
  
  METHODS
  All study participants completed a computerized baseline neurocognitive assessment that included a measure of reaction time (RT comp), in addition to a clinical measure of reaction time that assessed how far a standard measuring device would fall prior to the athlete catching it (RT clin).
  
  
  METHODS
  Validity was assessed by determining the correlation between RT clin and RT comp. Reliability was assessed by measuring the intraclass correlation coefficients (ICCs) between the repeated measures of RT clin and RT comp taken 1 year apart.
  
  
  RESULTS
  In the first year of study, RT clin and RT comp were positively but weakly correlated (rs = 0.229, P < 0.001). In the second year, there was no significant correlation between RT clin and RT comp (rs = 0.084, P = 0.084). Both RT clin [ICC = 0.608; 95% confidence interval (CI), 0.434-0.728] and RT comp (ICC = 0.691; 95% CI, 0.554-0.786) had marginal reliability.
  
  
  CONCLUSIONS
  In a population of high school athletes, RT clin had poor validity when compared with RT comp as a standard. Both RT clin and RT comp had marginal test-retest reliability. Before considering the clinical use of RT clin in the assessment of sport-related concussions sustained by high school athletes, the factors affecting reliability and validity should be investigated further.
  
  
  CONCLUSIONS
  Reaction time impairment commonly results from concussion and is among the most clinically important measures of the condition. The device evaluated in this study has previously been investigated as a reaction time measure in college athletes. This study investigates the clinical generalizability of the device in a younger population.
  A video abstract showing how the RT clin device is used in practice is available as Supplemental Digital Content 1, http://links.lww.com/JSM/A43.
authors.affiliation: *Department of Pediatrics, Division of Sports Medicine, Nationwide Children's Hospital, Columbus, Ohio; †Department of Orthopaedics, Children's Hospital Colorado, Aurora, Colorado; ‡Center for Injury Research Policy, Nationwide Children's Hospital, Columbus, Ohio; §The Micheli Center for Sports Injury Prevention, Waltham, Massachusetts; and ¶Department of Orthopaedics, Division of Sports Medicine, Boston Children's Hospital, Boston, Massachusetts.
authors.forename: James
authors.initials: J
authors.lastname: MacDonald
authors.forename: Julie
authors.initials: J
authors.lastname: Wilson
authors.forename: Julie
authors.initials: J
authors.lastname: Young
authors.forename: Drew
authors.initials: D
authors.lastname: Duerson
authors.forename: Gail
authors.initials: G
authors.lastname: Swisher
authors.forename: Christy L
authors.initials: CL
authors.lastname: Collins
authors.forename: William P
authors.initials: WP
authors.lastname: Meehan
mesh_terms: D000293:Adolescent; D001265:Athletic Injuries / Q000175:diagnosis* / Q000503:physiopathology; D001924:Brain Concussion / Q000175:diagnosis* / Q000503:physiopathology; D003430:Cross-Sectional Studies; D005260:Female; D005538:Football / Q000293:injuries*; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D011930:Reaction Time / Q000502:physiology*; D015203:Reproducibility of Results; D012916:Soccer / Q000293:injuries*