Hewson Paul J
Environment Directorate, Devon County Council, Exeter, United Kingdom.
Traffic Inj Prev. 2005 Jun;6(2):127-34. doi: 10.1080/15389580590931590.
Bicycle helmets have been advocated as a means of reducing injury among cyclists. This assertion, derived from a number of case controlled studies carried out in hospitals, conflicts with results from population level studies. In the Western countries where these case control studies have been performed, it appears that cycling morbidity is dominated by sports and leisure users. The generalizability of studies on helmet effectiveness in relation to utilitarian transport cycling is not clear. This study therefore considers population level data for reported road traffic injuries of cyclists and pedestrians.
Generalized linear and generalized additive models were used to investigate patterns of pedestrian and cyclist injury in the UK based on the police reported "Stats 19" data. Comparisons have been made with survey data on helmet wearing rates to examine evidence for the effectiveness of cycle helmets on overall reported road casualties. While it must be acknowledged that police casualty reports are prone to under-reporting, particularly of incidents involving lower severity casualties the attractive feature of these data are that by definition they only concern road casualties.
There is little evidence in UK from the subset of road collisions recorded by the police corresponding to the overall benefits that have been predicted by the results of a number of published case controlled studies. In particular, no association could be found between differing patterns of helmet wearing rates and casualty rates for adults and children.
There is no evidence that cycle helmets reduce the overall cyclist injury burden at the population level in the UK when data on road casualties is examined. This finding, supported by research elsewhere could simply be due to cycle helmets having little potential to reduce the overall transport-related cycle injury burden. Equally, it could be a manifestation of the "ecological fallacy" where it could be conceived that the existence of various sub-groups of cyclists, with different risk profiles, may need to be accounted for in understanding the difference between predicted and realised casualty patterns.
自行车头盔一直被倡导作为减少骑车者受伤的一种方式。这一观点源于在医院进行的多项病例对照研究，但与基于人群水平研究的结果相矛盾。在进行这些病例对照研究的西方国家，似乎骑车受伤情况主要发生在从事运动和休闲活动的骑车者中。关于头盔对实用性交通骑行有效性研究的可推广性尚不清楚。因此，本研究考虑了关于骑车者和行人道路交通事故报告的人群水平数据。
基于警方报告的“Stats 19”数据，使用广义线性模型和广义相加模型来研究英国行人与骑车者的受伤模式。已将其与头盔佩戴率的调查数据进行比较，以检验自行车头盔对总体报告道路伤亡有效性的证据。虽然必须承认警方伤亡报告容易漏报，尤其是涉及低严重程度伤亡的事故，但这些数据的吸引人之处在于，根据定义，它们仅涉及道路伤亡。
在英国，从警方记录的道路碰撞子集中几乎没有证据表明存在一些已发表病例对照研究结果所预测到的总体益处。特别是，在成人和儿童中，未发现不同头盔佩戴率模式与伤亡率之间存在关联。
当检查道路伤亡数据时，没有证据表明在英国人群水平上自行车头盔能减轻骑车者总体受伤负担。这一发现，得到其他地方研究的支持，可能仅仅是因为自行车头盔减轻与交通相关的骑车者总体受伤负担的潜力很小。同样，这也可能是“生态谬误”的一种表现，即可以设想，在理解预测伤亡模式与实际伤亡模式之间的差异时，可能需要考虑具有不同风险特征的骑车者各个亚组的存在。
