Effectiveness of different types of motorcycle helmets and effects of their improper use on head injuries.

Background: Differences among three helmet types and the ineffectiveness of improper helmet use in preventing head injuries are speculated about but are seldom explored with evidence. A case-control study was conducted to examine how different helmet types and improper helmet use affected protection against head injuries among motorcyclists in Taiwan.

Methods: Case motorcyclists comprised 435 persons who sought emergency care due to head injuries at a medical centre in west-central Taiwan over an 8-month period and 23 motorcyclists who died from head injuries at the scene of the crash; 458 motorcyclists who had non-head injuries were used as the control group, and their crashes occurred within 1 hour earlier or later than the corresponding cases. Information on helmet type was validated by interviewing motorcyclists who were refuelling at petrol stations.

Results: A conditional logistic regression analysis showed that compared with helmeted motorcyclists, non-helmeted motorcyclists were more than four times as likely to have head injuries [odds ratio (OR) 4.54; 95% confidence interval (CI) 1.25-16.5] and ten times as likely to have brain injuries (OR 10.4; 95% CI 1.82-59.2). Compared with motorcyclists wearing full-face helmets, those wearing half-coverage helmets were more than twice as likely to have head injuries (OR 2.57; 95% CI 1.50-4.40) and brain injuries (OR 2.10; 95% CI 1.01-4.38). Compared with motorcyclists with firmly fastened helmets, those with loosely fastened helmets increased their risk of head injury (OR 1.94; 95% CI 1.33-2.82) and were more than twice as likely to have brain injuries (OR 2.50; 95% CI 1.47-4.25).

Conclusions: Of the three helmet types, half-coverage helmets provided motorcyclists the least protection from head injuries. Furthermore, wearing a loosely fastened helmet may compromise any potential protection.