Bicycle helmet legislation for the uptake of helmet use and prevention of head injuries

 

Abstract

Background

Evidence exists to suggest that bicycle helmets may reduce the risk of head injuries to cyclists, however helmets are not uniformly worn by all bicycle users. Legislation has been enacted in some countries and jurisdictions to mandate helmet use by cyclists, however the issue remains controversial with opponents arguing that helmet laws may inhibit people from bicycle riding and thus from gaining the associated health benefits, or that other countermeasures (e.g. improved road safety) may have been responsible for the observed decline in head injuries.

Objectives

To assess the effects of bicycle helmet legislation on bicycle-related head injuries and helmet use, and the occurrence of unintended adverse consequences.

Search methods

We searched Cochrane Central Register of Controlled Trials (The Cochrane Library 2009, Issue 1); The Cochrane Injuries Group specialised register (searched July 2009), MEDLINE (Ovid SP) (1950 to April 2010), EMBASE (Ovid SP) (1980 to April 2010), CINAHL (EBSCO) (1982 to April 2010), TRANSPORT (Ovid SP) (1988 to September 2009) and other specialist electronic databases. In addition we searched government websites, handsearched selected journals and examined the reference lists of selected publications.

Selection criteria

We included studies that reported changes in either the number of head injuries, helmet use or bicycle use post- versus pre-legislation. Only studies that included a concurrent control group and which reported on the effect of legislation implemented at either the country, state or province wide level were included.

Data collection and analysis

Two authors independently extracted data and assessed methodological quality. The data were not appropriate for meta-analysis, thus the results of the included studies have been reviewed narratively.

Main results

Six studies, all with a non-randomised, controlled before and after study design met the inclusion criteria. For each of the studies, bicycle helmet legislation had been enacted for children only. Adults were used as controls in five of the studies, whilst jurisdictions with no helmet legislation were used as controls in the sixth. One study reported on bicycle related mortality while three of the studies reported on changes in head injury rates and three reported on changes in helmet use. There were no included studies reporting change in bicycle use or other adverse consequences of legislation. In three studies, statistically significant decreases in mortality or head injuries were reported following the implementation of helmet legislation compared with controls, whilst one reported a non-statistically significant decline in head injuries. Bicycle helmet use increased statistically significantly post-legislation in all three of the studies reporting on helmet use.

Authors' conclusions

Bicycle helmet legislation appears to be effective in increasing helmet use and decreasing head injury rates in the populations for which it is implemented. However, there are very few high quality evaluative studies that measure these outcomes, and none that reported data on possible declines in bicycle use.

 

Plain language summary

Bicycle helmet legislation for the uptake of helmet use and prevention of head injuries

Cycling is a popular past-time among children and adults and is highly beneficial as a means of transport and obtaining exercise. However, cycling related injuries are common and can be severe, particularly injuries to the head.

Bicycle helmets have been advocated as a means of reducing the severity of head injuries, however voluntary use of helmets is low among the general population. Bicycle helmet laws mandating their use have thus been implemented in a number of jurisdictions word-wide in order to increase helmet use. These laws have proved to be controversial with opponents arguing that the laws may dissuade people from cycling or may result in greater injury rates among cyclists due to risk compensation. This review searched for the best evidence to investigate what effect bicycle helmet laws have had. There were no randomised controlled trials found, however five studies with a contemporary control were located that looked at bicycle related head injury or bicycle helmet use. The results of these studies indicated a positive effect of bicycle helmet laws for increasing helmet use and reducing head injuries in the target population compared to controls (either jurisdictions without helmet laws or non-target populations). None of the included studies measured actual bicycle use so it was not possible to evaluate the claim that fewer individuals were cycling due to the implementation of the helmet laws. Although the results of the review support bicycle helmet legislation for reducing head injuries, the evidence is currently insufficient to either support or negate the claims of bicycle helmet opponents that helmet laws may discourage cycling.

 

摘要

背景

自行車安全帽法規用以提升安全帽的使用並預防頭部受傷

有證據顯示自行車安全帽也許可以減少騎士頭部受傷的風險，然而所有的自行車騎士並非統一佩帶安全帽。有些國家已頒佈法規來規定騎自行車需使用安全帽，然而這個議題仍具有爭議，反對者認為這也許會抑制民眾騎自行車，及從而獲得相關的健康福利，或其他的措施也可以減少頭部受傷的發生。

目標

評估自行車安全帽法規對於自行車相關的頭部受傷與安全帽使用，及發生未預期的負面結果的影響。

搜尋策略

我們檢索CENTRAL，the Cochrane Injuries Group's specialised register，MEDLINE，EMBASE，TRANSPORT及其他的專業電子資料庫，至2006年2月止。此外我們檢索政府的網站，人工搜尋選定的期刊並評估已選定之發表文章的參考文獻。

選擇標準

我們納入報告頭部受傷，安全帽使用或法規前後自行車使用改變量的研究。只有納入同時存在對照組且其報告法規實行於國家，州或省範圍的研究。

資料收集與分析

兩名作者分別摘錄資料並評估方法學品質。資料不適合進行統合分析，因此納入研究的結果採用描述性的回顧。

主要結論

五篇來自北美洲的研究皆符合納入標準。每一篇研究，只有頒布對孩童的自行車安全帽法規。其中四篇研究以成人作為對照組，第五篇研究以司法沒有安全帽法規作為對照組。三篇研究指出頭部受傷率有改變，而三篇研究指出安全帽的使用有改變。納入的研究指出自行車使用或其他法規的負面結果沒有改變。兩篇研究指出，相較於對照組，安全帽法規實行後頭部受傷比率有統計上顯著減少，一篇研究則指出沒有統計上顯著減少。三篇研究指出在法規實行後自行車安全帽使用有統計上顯著增加。

作者結論

實行自行車安全帽法規對於民眾增加安全帽使用並減少頭部受傷率似乎有效。然而，很少有高品質的評估性研究測量這些結果，且沒有研究資料指出可能減少自行車的使用。

翻譯人

本摘要由高雄榮民總醫院金沁琳翻譯。

此翻譯計畫由臺灣國家衛生研究院(National Health Research Institutes, Taiwan)統籌。

總結

在孩童及成人間騎自行車是一種過去盛行，且是高度有效作為交通運輸並獲得運動的方法。然而，與騎自行車相關的受傷是常見的且可以是嚴重的，尤其是頭部受傷。自行車安全帽被提倡作為減少頭部受傷嚴重度的方法，然而一般民眾自願使用安全帽的比例不高。因此全世界許多司法單位實行自行車法規以增加安全帽使用。這些法律具有爭議性，許多反對者認為法律也許會阻礙民眾騎自行車，或因為風險賠償而導致騎士較高的受傷率。這篇回顧搜尋最佳證據以研究自行車安全帽法規的影響。沒有發現隨機對照試驗，然而五篇有對照組的研究發現自行車與頭部受傷或自行安全帽的使用有關。這些研究結果指出，目標族群相較於對照組(無安全帽法律的司法規定或非目標族群)，自行車安全帽法規對於增加安全帽使用及減少頭部受傷具有正面效果。納入的研究沒有測量實際上自行車的使用，因此無法評估因為實行安全帽法規而使較少人騎自行車的主張。雖然回顧的結果支持自行車安全帽立法以減少頭部受傷，目前無充分證據支持或反對自行車安全帽反對者所認為安全帽法律也許會抑制騎自行車的主張。