Table 1

Definitions

Key termDefinition
EffectivenessEffectiveness refers to a protective effect of helmet wear in relation to the outcome of interest as interpreted by a statistically significant result where the upper bound of the 95% CI of the combined effect is less than one
Head injuryIncludes head injuries of all severity levels (including traumatic brain injury) necessitating treatment by ski patrollers and/or physicians. Such head injuries may lead to traumatic amnesia, loss of consciousness, craniofacial factures, intracranial lesions such as cerebral contusions, subarachnoid haemorrhage, subdural haematoma, intraventricular haemorrhage, etc. Included in the definition are concussions and other indicators pointing to a probable head injury including coma, lost of consciousness, or an abnormal Glasgow Coma Score.
InterventionIntervention refers to the exposure measure, which is the use of helmets while skiing or snowboarding