Table 2

Characteristics of included studies

StudySportStudy designDuration (seasons) and locationEligibility/study populationExposure measuresOutcome measuresMain results
Macnab et al2Ski and snowboardCase–controlNovember 1998 to May 1999 (one season) at a major ski resort in British Columbia, CanadaAll young skiers and snowboarders (less than 13 years of age) presenting with head, face, or neck injuries to the one central medical facility at the base of the mountainHelmet useHead, neck, face injuries: treatment by physicians (n=70)Head and neck injury: Among those without helmets, relative risk of head/neck/face injury was 2.24 (95% CI 1.23 to 4.12) compared with those who wore helmets
Cervical spine injuries: treatment by physicians (n=22)Cervical spine injuries: Of the children who sustained a cervical spine injury, 32% were wearing a helmet at the time of the incident (RR 2.0, 95% CI 0.80 to 5.6; p=0.15 for cervical spine injury when not wearing a helmet). None of the cervical spine injuries were considered major.
Hagel et al15Ski and snowboardMatched case–control and case crossover studyNovember 2001 to April 2002 (one season) at 19 ski resorts in Quebec, CanadaCases=1082 skiers and snowboardersHelmet useHead injuries: treatment by ski patrollers (n=693)Head injury: The adjusted OR for helmet use was 0.71 (95% CI 0.55 to 0.92), and for those with more severe head injuries requiring evacuation by ambulance it was 0.44 (0.95% CI 0.24 to 0.81).
Controls=3295 skiers and snowboardersNeck injuries: treatment by ski patrollers (n=131)Neck injury: The adjusted OR for helmet use for participants with any neck injury was 0.62 (0.33 to 1.19) and for participants who required evacuation by ambulance for neck injuries it was 1.29 (0.41 to 4.04).
Sulheim et al16Ski and snowboardCase–control2002 winter (one season) at eight major Norwegian alpine resortsCases=3277 injured skiers and snowboardersHelmet use, injury typeHead injuries: treatment by ski patrollers (n=578)Head injury: The adjusted OR for helmet use was 0.40 (95% CI 0.30 to 0.55), and for those with more severe injuries it was 0.43 (95% CI 0.25 to 0.77).
Controls=2992 non-injured controlsNeck injuries: treatment by ski patrollers (n=62)Neck injury: The adjusted OR for helmet use was 0.68 (95% CI 0.34 to 1.35), indicating an association with a lower risk of neck injuries (statistically insignificant).
Mueller et al1Ski and snowboardCase–control2000–2005 (five seasons) at three ski resorts in Western USACases=4224Helmet useHead injuries: treatment by ski patrollers (n=2537)Head injury: The adjusted OR for helmet use was 0.85 (95% CI 0.76 to 0.93).
Controls=17674Neck injuries: treatment by ski patrollers (n=565)Neck injury: The adjusted OR for helmet use was 0.91 (95% CI 0.72 to 1.14).
Greve et al17Ski and snowboardRetrospective cohortInjuries that occurred from July 2002 to July 2004 retrieved from emergency department medical records at nine medical facilities in Colorado, New York and VermontSkiers and snowboarders who sustained a head injury as defined by International Classification of Diseases-9 codes for acute head injuries (n=1013 total patients)Helmet useHead injuryThere was a significantly lower incidence of head injuries involving loss of consciousness in helmet users who struck a fixed object (χ2: 5.8; p<0.05).
Sacco et al20Ski and snowboardRetrospective cohortInjuries that occurred from January 1990 to December 1995 at Vermont, USAMedical records of a single paediatric and adult Level 1 trauma centre were evaluated with admissions for injuries caused by alpine skiing or snowboarding (n=279)Helmet useHead injuryHelmets were not worn by those sustaining head injuries (n=19) or fatalities (n=26).
Fukuda et al18SnowboardCase-seriesDecember 1999 to March 2003 (four seasons) at Uonuma ski resort, Niigata, Japan1190 consecutive patients who experienced head injury during snowboarding and consulted Saito Memorial HospitalHelmet use, knit cap useSerious head injuries requiring medical attention (n=549)No significant association between helmet or knit cap wearing and the occurrence of serious head injury (p=0.056)
Bridges et al22Ski, snowboard, snowbladeCase-series1999–2000 (one season) at Mont Tremblant, Quebec, CanadaAll participants who presented with themselves to the ski patrol with traumatic injury related to their sport (n=162)Helmet useHead injury, neck injury, lower-extremity injuriesHead injury: Concussions represented 11% of all injuries.
Neck injury: There was no increase in neck injury related to helmet use.
Machold et al19SnowboardCross-sectionalWinter season of 1996/1997 in AustriaOf 7221 students participating in winter sport programmes organised by Austrian schools, 2745 of those riding snowboards were asked to fill out questionnaires; 2579 snowboarders repliedNANAHead injury: A total of 196 snowboarders (7.6%) wore a helmet. In this group, no head injury occurred.
Ekeland and Rødven21Ski and snowboardCase-series1996–1998 (two seasons) at seven major Norwegian ski resortsA total of 3915 injuries and 32.894 million lift transports were recorded during the two seasonsHelmet useHead injury, knee injury, ankle injury, shoulder injuryOf the skiers and snowboarders suffering a head injury, only 9% wore a helmet. The percentage of uninjured skiers wearing a helmet is unknown.