Bicycle helmets and injury reduction and severity (product)

Conclusion: Convincing evidence for effectiveness

- The bicycle helmet and its efficacy in preventing head injury among cyclists is a much researched and discussed topic, generating impassioned arguments from all sides. According to several case-control studies, bicycle helmets are highly effective in preventing brain damage and scalp injuries. The most conservative estimates of competently executed studies abroad show a decline in the risk of head injury of approximately 45%. Advocates of the helmet point to these case control research from which it appears that the voluntary wearing of a bicycle helmet is effective in preventing head injury. Opponents, however, argue that following a statutory measure to make bicycle helmets mandatory in certain countries and states, no decrease in the number of head injuries among cyclists was observed.

However, not all the evidence points in the same direction. In one review it is found that there are no differences in non head injuries between cyclists with or without helmets. Furthermore, it is argued that there is a difference in riding style between cyclists with or without helmets. It is also found that helmets cannot prevent injuries to the lower face, but they do protect against injuries to the mid and upper face. Some trials, 3 in total, investigated the risk of neck injury when wearing a bicycle helmet. Although in every trial the number of neck injuries was higher among bicycle helmet wearers, the combined results were not significant (OR 1.36; 95% BI 1.00-1.86).

A bicycle helmet can't offer protecting against all head injuries due to it's shape. But wearing a bicycle helmet reduces the risk for head. mid and upper facial injury and brain injury.

The type of helmet is an important factor: a hard shell helmet reduces risk, while a foam shell is less effective (there is more risk of getting a face injury). Also, helmets should meet the standards the reduce the injury risk..

A number of studies have shown that the effectiveness of bicycle helmets seem to be greater in children. In addition, in none of the included studies a distinction was made in the circumstances (sports or leisure time) in which the accidents occurred.

In addition, most studies were performed in non-European countries (USA, Canada, Australia, etc.). The findings might be different when performing case-control studies in European countries.

Recommendations (for research & practice)

It is recommended that one should wear a helmet while cycling. The use of a bicycle helmet by children (age 4-8) is especially emphasized, since these children are more prone to bicycle-related injuries and the effectiveness of bicycle helmets seem to be greater in children.

More research should be performed to gain insights in:
1. Negative effects of wearing a bicycle helmet (for example: helmets users are more likely for risk taking behaviour or visa versa)
2. Innovation of helmets and their effectiveness on injury reduction
3. Effective interventions to increase the (proper) use of helmets
4. Helmet efficacy in European countries
5. Types of accidents associated with injuries
6. Care should be taken in the selection of control groups; preferably controls should be selected from the general population.

In addition, to make the studies more comparable, more consensus should be reached on the definitions of head, brain and face injuries.

Review Date: 30/03/2010
Version: 1.2
Status: Publish

Procedure
Articles and documents were included that were published until 2009. The outcomes of the study were not reviewed by experts in the field of vulnerable road users.

Background documents

Bicycle helmets : a review of their effectiveness : a critical review of the literature (version 1)
Elisabeth Towner, Theresa Dowswell, Matthew Burkes ... [et al.] (2002)

Protective effect of different types of bicycle helmets (version 1)
Kari Schroder Hansen, Lars Birger Engesaeter, Asgaut Viste (2003)

Bicycle injuries and safety helmets in children : review of research (version 1)
Sherrilyn Coffman (2003)

The Cochrane Collaboration and bicycle helmets (version 1)
W.J. Curnow (2005)

Helmets for preventing head and facial injuries in bicyclists (version 1)
D.C. Thompson, F.P. Rivara, R. Thompson (2006)

De fietshelm bij kinderen en jongeren : onderzoek naar de voor- en nadelen (version 1)
H.J. Kemler, W. Ormel, L. Jonkhoff ... [et al.] (2009)