" Always wear a helmet, as it may help to prevent serious head injuries, make sure it fits you and conforms to current British Standards. "
https://www.westyorkshire.police.uk/cyc ... d-security added a link to one police force.
The advice is understandable in the hope they may save injury. A selection of information, listed below shows why advice to wear a cycle helmets is questionable and if given, should be with a suitable warning that they may not improve overall safety.
Page references to specific parts of the following report are provided;
'Weaknesses with a meta-analysis approach to assessing cycle helmets'. Feb 2017
http://worldtransportjournal.com/wp-con ... eb-opt.pdf
pages 28/29 refers to;
A)
In New Zealand, from 1989 to 2011, average time spent cycling (on roads and footpaths) fell by 79% for children aged 5-12 (from 28 to 6 minutes per person per week) and 81% for 13-17 year olds (52 to 10 mins/person/week).
Adult cycling declined from 8 to 5 minutes/person/week then trended back up to 8 minutes. Graphs of cycle use over time provide strong evidence that the requirement to wear a helmet discouraged cycling. The reductions in cycling were accompanied by increased injury rates. Between 1989 and 2012, fatal or serious injuries per million hours of cycling increased by 86% for children (from 49 to 91), 181% for teenagers (from 18 to 51) and 64% for adults (from 23 to 38).[i]
page 29 refers to;
B)
Robinson 1996 also refers to the incidence of hitting their head/helmet in a cycling accident was "significantly higher for helmet wearers (8/40 vs 13/476, i.e. 20% vs 2.7%, p 0.00001)". A bare head width of approximately 150mm may avoid contact compared to a helmeted head at approximately 200mm width. Helmet wearers often report hitting their helmets and the 7 fold increase may have long term effects that may not show up in a meta–analysis.
page 29 refers to;
C)
Erke and Elvik 2007[i] examined research from Australia and New Zealand and stated: "There is evidence of increased accident risk per cycling-km for cyclists wearing a helmet. In Australia and New Zealand, the increase is estimated to be around 14 per cent." The findings were based on six reports, four from when legislation was in place.
page 29 refers to;
D)
A recent report detailed that cyclists wearing helmets had more than twice the odds of suffering an injury than cyclists not wearing helmets, (104) with an OR value 2.81, 95% CL =1.14, 6.94.
104 Porter AK, Salvo D, Kohl HW, Correlates of Helmet Use Among Recreation and Transportation Bicyclists, AJPM 2016. https://www.ncbi.nlm.nih.gov/pubmed/27866599
The above information provides evidence that helmet wearers may incur a higher accident rate, per cycling kilometre or in comparison to non-wearers or as helmet use increased in proportion.
E)
Another evaluation, published by the New Zealand Medical Journal, detailed;
Injury data11 for 2006–09 compared to 1998/90 shows an average reduction of approximately 18.5% (858/1052), compared to cycling reducing by 38.5% (24/39 million hours). The approximate risk per million hours cycling therefore increased from 27 to 35.7 or by 32%.
Refer to https://www.nzma.org.nz/journal/read-th ... cle-clarke
F)
A 2015 report, ‘Overestimation of the effectiveness of the bicycle helmet by the use of odds ratios’ details;
Three cases could be found in the literature with sufficient data to assess both risk ratios and odds ratios: the Netherlands, Victoria (Australia) and Seattle (U.S.A). In all three cases, the problem of overestimation of the effectiveness of the helmet by using odds ratios did occur. The effect ranges from small (+ 8 % ) to extremely large ( > + 400 %). Contrary to the original claim of these studies, in two out of three cases the risk of getting a head injury proved not to be lower for helmeted cyclists. Moreover, in all three cases the risk of getting a non-head injury proved to be higher for cyclists with a helmet.
Refer;
http://www.fietsberaad.nl/?lang=nl&repo ... dds+ratios
G)
Page 20 of ‘Evaluation of Australia's bicycle helmet laws, The Sports Science Summit, O2 venue London UK http://www.cycle-helmets.com/au-assessment-2015.pdf Presented 14 January 2015, details;
4) Robinson's 1996 report provided injury data for children. In Victoria, the equivalent number of injuries for pre law levels of number of cyclists increased by 15% from 1990 to 1992. Robinson provides data in Table 2 for children in NSW. The equivalent number of injuries increased from 1310 (384 head + 926 other injuries) pre law in 1991 to 2083 (488 head + 1595 other injuries) in 1993. The relative injury rate increased by 59% from 1310 to 2083. The relative increase in 'other' injuries of 72% and 27% for 'head' raises serious concerns. The proportion of head injuries decreased from 29.3% to 23.4% and would give the impression of a benefit if viewed in isolation.
H)
The report, ‘The Case against bicycle helmets and legislation’, Velo City Confernece paper, Munich, 2007.
http://www.ta.org.br/site/Banco/7manuai ... helmet.pdf
Details some of the potential positive and potential negative aspects of wearing a helmet, two potential benefits are listed compared with 13 potential disadvantages. A number of reports are listed A1 to A14 indicating a higher accident rate associated with wearing helmets.
Cost of accidents for helmet wearers v non-wearers
One report provided hospital costs associated with bicyclists and motorcyclists, who had incurred head injuries and been admitted. On average for bicyclists the medium costs for helmeted were $6500 v $5600 for non-helmeted.
For motorcyclists the medium costs for helmeted were $7700 v $11400 for non-helmeted.
Bicyclists not wearing helmets had a lower cost than those helmeted.
Refer to; https://www.researchgate.net/publicatio ... ntre_study
‘The effectiveness of helmets in reducing head injuries and hospital treatment costs: A multicentre study’ Dinh et al, MJA, 6 May, 2013
Even if helmet use reduces the proportion of head injuries, net overall safety in terms of overall accidents is reduced according to know research based on per km travelled when helmeted. So there is no sound safety reason to advise that helmets should be worn for normal cycling.
The UK's National Children's Bureau (NCB) provided a detailed review in 2005 stating "the case for helmets is far from sound", "the benefits of helmets need further investigation before even a policy supporting promotion can be unequivocally supported" and "the case has not yet been convincingly made for compulsory use or promotion of cycle helmets".
Refer;
Cycle helmets: An overview of the evidence
http://www.ctc.org.uk/sites/default/fil ... ncebrf.pdf
The Cyclist Touring Club (Cycling UK national cycling charity) states that "Individuals should be free to make their own decisions about whether or not to wear helmets, with parents making these decisions in the case of younger children. Their decisions should be informed by clear information about the uncertainties over the benefits or otherwise of helmets. ' and "it is therefore entirely possible that helmet wearing might have a net disbenefit even in safety terms (a point also suggested by some of the empirical evidence), not to mention the health and other disbenefits identified above".
Cycling UK state;
“Cycling UK is opposed to both cycle helmet laws and to helmet promotion campaigns because these are almost certainly detrimental to public health. Evidence shows that the health benefits of cycling are so much greater than the relatively low risks involved, that even if these measures caused only a very small reduction in cycle use, this would still almost certainly mean far more lives being lost through physical inactivity than helmets could possibly save, however effective”.
and
“In any case, there are serious doubts about the effectiveness of helmets. They are, and can only be, designed to withstand minor knocks and falls, not serious traffic collisions. Some evidence suggests they may in fact increase the risk of cyclists having falls or collisions in the first place, or suffering neck injuries.”
Cycle helmets: An overview of the evidence
http://www.ctc.org.uk/sites/default/fil ... ncebrf.pdf accessed 27.11.2014
In the UK, some 8,000 years of average cycling will produce one clinically severe head injury*. For the average person cycling for 60 years, this relates to one severe head injury per 133 lifetimes of cycling, less than 1% risk per average lifetime. This overall small relative risk is much lower than the risk of having extra accidents due to helmet use.
* Wardlaw MJ. Three lessons for a better cycling future. BMJ : British Medical Journal. 2000;321(7276):1582-1585.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1119262/
The overall evidence is not sufficiently sound to justify advising cyclists to wear cycle helmets for normal cycling. A suitable warning should be given that they may not improve overall safety.
