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.