Compulsory cycle helmet laws may reduce head injuries
MedWire News: Bicycle-related head injuries have fallen significantly since compulsory cycle helmet legislation has been introduced, report Australian researchers, who add that the observed decrease in head injury rates could be attributed to the legislation.
Several studies have found helmet wearing to be associated with significant reductions in head, brain, and facial injuries, while others have rejected these findings, stating that the effects associated with helmet wearing may not accurately reflect what occurs at a population level.
To address these discrepancies, Jake Olivier (University of New South Wales, Sydney) and colleagues analyzed hospital admissions data from New South Wales - an Australian state that introduced mandatory helmet wearing for cyclists in 1991 - for a 36 month period centered at the time the legislation came into effect.
The team compared the rates of head injuries relative to arm and leg injuries (referred to collectively as limb injuries) for cyclists and pedestrians over this time period. Equal rates of head and limb injuries over time were assumed.
In all, there were 2154 hospital admissions involving head injuries incurred whilst cycling, along with 2221 arm injuries and 1196 leg injuries.
Prior to the legislation, the rates of all injuries showed a moderate decrease, with mean percentage decreases ranging from 4.5% to 23.6% per year. After the legislation was introduced, this trend was reversed, with overall rates of injuries increasing by between 3.5% and 21.2% per year.
This, however, is thought to represent background effects in transport safety, comment Olivier et al.
Binomial model estimates revealed that among cyclists, head injury rates decreased significantly more than limb injury rates at the time of legislation; a pattern that was not observed among pedestrians.
This suggests that "in addition to the overall decrease in cyclist injury rates around the time of legislation there was a further decline in head injury rates," say the authors.
The researchers predict that the legislation-attributable decrease in head injuries was 25% or 29%, depending on whether arm or leg injuries were the comparator.
These findings suggest that recent calls for a repeal to helmet laws in Australia should be rejected, write Olivier and co-authors in the journal Accident Analysis and Prevention. They add that this analysis could be applied to similar data from other jurisdictions in the future.
MedWire (www.medwire-news.md) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2011
By Nikki Withers