title: An observational method to code concussions in the National Hockey League (NHL): the heads-up checklist.
abstract: BACKGROUND
  Development of effective strategies for preventing concussions is a priority in all sports, including ice hockey. Digital video records of sports events contain a rich source of valuable information, and are therefore a promising resource for analysing situational factors and injury mechanisms related to concussion.
  
  
  OBJECTIVE
  To determine whether independent raters reliably agreed on the antecedent events and mechanisms of injury when using a standardised observational tool known as the heads-up checklist (HUC) to code digital video records of concussions in the National Hockey League (NHL).
  
  
  METHODS
  The study occurred in two phases. In phase 1, four raters (2 naïve and 2 expert) independently viewed and completed HUCs for 25 video records of NHL concussions randomly chosen from the pool of concussion events from the 2006-2007 regular season. Following initial analysis, three additional factors were added to the HUC, resulting in a total of 17 factors of interest. Two expert raters then viewed the remaining concussion events from the 2006-2007 season, as well as all digital video records of concussion events up to 31 December 2009 (n=174).
  
  
  RESULTS
  For phase 1, the majority of the factors had a κ value of 0.6 or higher (8 of 15 factors for naïve raters; 11 of 15 factors for expert raters). For phase 2, all the factors had a total percent agreement value greater than 0.8 and κ values of >0.65 for the expert raters.
  
  
  CONCLUSIONS
  HUC is an objective, reliable tool for coding the antecedent events and mechanisms of concussions in the NHL.
authors.affiliation: David L. MacIntosh Sport Medicine Clinic, Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Michael G
authors.initials: MG
authors.lastname: Hutchison
authors.forename: Paul
authors.initials: P
authors.lastname: Comper
authors.forename: Willem H
authors.initials: WH
authors.lastname: Meeuwisse
authors.forename: Ruben J
authors.initials: RJ
authors.lastname: Echemendia
mesh_terms: D001265:Athletic Injuries / Q000517:prevention & control; D001924:Brain Concussion / Q000517:prevention & control*; D057189:Checklist / Q000379:methods*; D059019:Clinical Coding / Q000379:methods*; D006688:Hockey / Q000293:injuries*; D006801:Humans; D015588:Observer Variation; D015203:Reproducibility of Results; D013178:Sports Medicine / Q000379:methods*; D014741:Video Recording
keywords: Concussion; Ice hockey; Injury Prevention