title: Helmet use and risk of head injuries in alpine skiers and snowboarders: changes after an interval of one decade.
abstract: BACKGROUND
  In a previous study, we concluded that a safety helmet can reduce the risk for head injury by 60%. Other studies reported similar effects, resulting in a general recommendation to wear a helmet while skiing or snowboarding.
  
  
  OBJECTIVE
  To determine the effect of the expected increased helmet wear on the risk of head injury one decade after the recommendation.
  
  
  METHODS
  Ski patrols reported injury cases in major Norwegian alpine ski resorts. Injury type, helmet use and other risk factors were recorded. A multiple logistic regression analysis was used to assess the relation between individual risk factors and the risk of head injuries by comparing head injured skiers (cases) with skiers and snowboarders who reported other injuries (controls).
  
  
  RESULTS
  Helmet use was associated with improved odds for head injuries (OR: 0.45, 95% CI 0.34 to 0.60; p<0.001) in 2002; this effect was attenuated in 2010 (OR: 0.79, 95% CI 0.63 to 0.98; p=0.02), and not significant in 2011 (OR: 0.80, 95% CI 0.60 to 1.06; p=0.12). For potentially severe head injuries, the protective effect of using a helmet was better sustained over the observation period, from an OR of 0.44 (95% CI 0.28 to 0.68, p<0.001) in 2002 to an OR of 0.74 (95% CI 0.57 to 0.97, p=0.02) in 2010 and 0.67 (95% CI 0.47 to 0.96; p=0.03) in 2011.
  
  
  CONCLUSIONS
  We observed an unexpected reduction in the protective effect of a skiing helmet. This may be due to new skiing trends in the alpine resorts.
authors.affiliation: Orthopaedic Department, Gjoevik hospital, SIHF, Gjøvik, Norway.|Oslo Sports Trauma Research Center, Norwegian School of Sport Sciences, Oslo, Norway.
authors.forename: Steinar
authors.initials: S
authors.lastname: Sulheim
authors.affiliation: Martina Hansens Hospital, Baerum, Norway.
authors.forename: Arne
authors.initials: A
authors.lastname: Ekeland
authors.affiliation: Oslo Sports Trauma Research Center, Norwegian School of Sport Sciences, Oslo, Norway.
authors.forename: Ingar
authors.initials: I
authors.lastname: Holme
authors.affiliation: Oslo Sports Trauma Research Center, Norwegian School of Sport Sciences, Oslo, Norway.
authors.forename: Roald
authors.initials: R
authors.lastname: Bahr
mesh_terms: D000293:Adolescent; D001265:Athletic Injuries / Q000517:prevention & control*; D006259:Craniocerebral Trauma / Q000517:prevention & control*; D005260:Female; D006260:Head Protective Devices / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D009664:Norway; D012307:Risk Factors; D012865:Skiing / Q000293:injuries*; D055815:Young Adult
keywords: Alpine skiing; Helmet