title: Sports-related concussion increases the risk of subsequent injury by about 50% in elite male football players.
abstract: BACKGROUND
  Little is known about the short-term and long-term sequelae of concussion, and about when athletes who have sustained such injuries can safely return to play.
  
  
  OBJECTIVE
  To examine whether sports-related concussion increases the risk of subsequent injury in elite male football players.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  Injuries were registered for 46 male elite football teams in 10 European countries in the 2001/2002-2011/2102 seasons. Two survival models were used to analyse whether concussion increased the subsequent risk of an injury in the first year.
  
  
  RESULTS
  During the follow-up period, 66 players sustained concussions and 1599 players sustained other injuries. Compared with the risk following other injuries, concussion was associated with a progressively increased risk of a subsequent injury in the first year (0 to <3 months, HR=1.56, 95% CI 1.09 to 2.23; 3 to <6 months, HR=2.78, 95% CI 1.58 to 4.89; 6-12 months, HR=4.07, 95% CI 2.14 to 7.76). In the second model, after adjustment for the number of injuries in the year preceding the concussion, this injury remained significantly associated with the risk of subsequent injury in the first year (HR=1.47, 95% CI 1.05 to 2.05).
  
  
  CONCLUSIONS
  Concussion was a risk factor for sustaining subsequent injury within the following year. In-depth medical evaluation, which includes neurological and cognitive assessment, is warranted within the concussion management and return-to- play process.
authors.affiliation: Department of Surgical and Perioperative Sciences, Sports Medicine, Umeå University, Umeå, Sweden.
authors.forename: Anna
authors.initials: A
authors.lastname: Nordström
authors.affiliation: Department of Community Medicine and Rehabilitation, Geriatric Medicine, Umeå University, Umeå, Sweden.
authors.forename: Peter
authors.initials: P
authors.lastname: Nordström
authors.affiliation: Football Research Group, Division of Community Medicine, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden.
authors.forename: Jan
authors.initials: J
authors.lastname: Ekstrand
mesh_terms: D000041:Absenteeism; D000328:Adult; D001265:Athletic Injuries / Q000453:epidemiology / Q000209:etiology; D001924:Brain Concussion / Q000453:epidemiology / Q000209:etiology*; D003072:Cognition Disorders / Q000175:diagnosis / Q000209:etiology; D005060:Europe / Q000453:epidemiology; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009460:Neurologic Examination / Q000379:methods; D011446:Prospective Studies; D012307:Risk Factors; D012916:Soccer / Q000293:injuries*; D055815:Young Adult
keywords: Concussion