title: Concussions during the 1997 Canadian Football League season.
abstract: OBJECTIVE
  To examine the incidence and characteristics of concussions for one season in the Canadian Football League (CFL).
  
  
  METHODS
  Retrospective survey.
  
  
  METHODS
  289 players reporting to CFL training camp. Of these, 154 players had played in the CFL during the 1997 season.
  
  
  METHODS
  Based on self-reported symptoms, calculations were made to determine the number of concussions experienced during the previous season, the duration of symptoms, the time for return to play after concussion, and any associated risk factors for concussions.
  
  
  RESULTS
  Of all the athletes who played during the 1997 season, 44.8% experienced symptoms of a concussion. Only 18.8% of these concussed players recognized they had suffered a concussion. 69.6% of all concussed players experienced more than one episode. Symptoms lasted at least 1 day in 25.8% of cases. The odds of experiencing a concussion increased 13% with each game played. A past history of a loss of consciousness while playing football and a recognized concussion while playing football were both associated with increased odds of experiencing a concussion during the 1997 season.
  
  
  CONCLUSIONS
  Many players experienced a concussion during the 1997 CFL season, but the majority of these players may not have recognized that fact. Players need to be better informed about the symptoms and effects of concussions.
authors.affiliation: McGill Sport Medicine Clinic, Department of Emergency Medicine, McGill University Health Center, Montreal, Quebec, Canada.
authors.forename: J S
authors.initials: JS
authors.lastname: Delaney
authors.forename: V J
authors.initials: VJ
authors.lastname: Lacroix
authors.forename: S
authors.initials: S
authors.lastname: Leclerc
authors.forename: K M
authors.initials: KM
authors.lastname: Johnston
mesh_terms: D000328:Adult; D001924:Brain Concussion / Q000453:epidemiology* / Q000503:physiopathology; D002170:Canada / Q000453:epidemiology; D003221:Confusion / Q000453:epidemiology; D004244:Dizziness / Q000453:epidemiology; D005538:Football / Q000293:injuries*; D006261:Headache / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D008297:Male; D008569:Memory Disorders / Q000453:epidemiology; D016017:Odds Ratio; D012008:Recurrence; D012189:Retrospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires; D013997:Time Factors; D014474:Unconsciousness / Q000453:epidemiology; D014786:Vision Disorders / Q000453:epidemiology