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Bicycle accidents – Do we only see the tip of the iceberg?
Injury, Int. J. Care Injured 43 (2012) 2026–2034
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Injury journal homepage: www.elsevier.com/locate/injury
Bicycle accidents – Do we only see the tip of the iceberg? A prospective multi-centre study in a large German city combining medical and police data C. Juhra a,*, B. Wiesko¨tter a, K. Chu a, L. Trost a, U. Weiss b, M. Messerschmidt b, A. Malczyk c, M. Heckwolf d, M. Raschke a a
University Hospital Mu¨nster, Department of Trauma-, Hand- and Reconstructive Surgery, Waldeyerstr. 1, D-48149 Mu¨nster, Germany Police Mu¨nster, Germany c German Insurance Association, German Insurers Accident Research, Germany d Mathias-Hospital, Rheine, Anaesthesiology Department, Germany b
A R T I C L E I N F O
A B S T R A C T
Article history: Accepted 16 October 2011
Introduction: Bicycles are becoming increasingly popular. In Mu¨nster, a German town with a population of 273,000, bicycles were the main method of transportation in 2009, used more often (37.8%) than cars (36.4%). Each day in Mu¨nster, bicycles are used around 450,000 times. In 1982, they were only used around 270,000 times a day. However, the increased use of bicycles has also led to an increased number of bicycle accidents. Methods: Between February 2009 and January 2010, data on bicycle-accidents leading to injuries were collected by the Police of Mu¨nster and in all emergency units of the six hospitals in Mu¨nster. A systematic acquisition of technical data from the police and the medical data from the hospitals were combined anonymously. None of the forms contained personal data of patients involved, except for patient age and sex as well as time and place of bicycle accidents to match the questionnaires. The data were entered into a central database (MS Access for input/MySQL for data retrieval). Results: 2250 patients were included in this study. For each of these patients either a patient record or a hospital record or a police record or a combination of any of these different records existed in our database. In total, 1767 patients received medical treatment at a hospital and 484 people included in the study did not go to a hospital. Three fatalities occurred as a result of bicycle accidents. Considering reasons for hospital admission, traumatic brain injuries were the leading cause (25.7%). However, the largest resource consumption was attributed to fractures of the upper extremities (36.8%) and lower extremities (29.9%) with major surgery. Discussion: Bicycle accidents occur more frequently than indicated by police records. The results of the Mu¨nster Bicycle Study have shown that the actual number of bicycle accidents exceeds the officially reported number by nearly two times. Since bicycle helmets cannot prevent accidents it is recommended not only to focus on helmet use as the only injury prevention method. Other factors, such as weather, pavement and default of traffic, roadworthiness of the bicycles or alcohol/drug abuse also affect the accident rates. ß 2011 Elsevier Ltd. All rights reserved.
Keywords: Bicycle accidents Traumatic brain injury Helmet Economic impact Fracture
Introduction Bicycles are becoming increasingly popular in Germany.1,2 The awareness of environmental issues, prices for gas, and an ever more mobile population are only some of the reasons for this. In Mu¨nster, a German town with a population of 273,000, bicycles were the main mode of transportation in 2009, used for trips more
* Corresponding author. Tel.: +49 251 83 56337, fax: +49 251 83 56318. E-mail address: [email protected] (C. Juhra). 0020–1383/$ – see front matter ß 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.injury.2011.10.016
often (37.8%) than the car (36.4%). The number of bicycles in Mu¨nster exceeds the number of the population by far (around 400,000 bicycles are owned by the 273,000 residents). Each day in Mu¨nster, bicycles are used around 450,000 times. In 1982 they were used only approximately 270,000 times a day.3 However, the increased use of bicycles has also led to an increased number of bicycle accidents. In 2009, according to police statistics, 1297 people were injured in traffic accidents in Mu¨nster, and nearly half of these victims (648) were involved in a bicycle accident. Three of these patients died because of their injuries.
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Whilst the number of recorded accidents is already high, the number of unrecorded cases is suspected to be even higher, as Hautzinger showed in a study on under-reporting of road traffic accidents in 1993.4 This is due to the nature of bicycle accidents, which often do not involve a third party or damage to property, hence rarely leading to the involvement of the police. If someone slips with his or her bike and falls, there is no reason for calling the police most of the time. If a high number of unreported cases exist, all which were previously known about bicycle accidents must be regarded with caution. Current knowledge on bicycle accidents is either gained by using clinical data alone or restricted to accidents recorded by the police. In order to obtain a realistic look at the bicycle accidents in Mu¨nster, the Mu¨nster police and all six hospitals in Mu¨nster with emergency departments reported all bicycle accidents with at least one injured cyclist over one year prospectively. We wanted to evaluate the actual number of bicycle accidents, the types and locations of these accidents, the use of protective gear such as a bicycle helmet, the type of bicycle used, the injury pattern and severity, the age distribution and the distribution of bicycle accidents over time. Materials and methods Between February 2009 and January 2010, data on bicycle accidents leading to injuries of cyclists were collected by the Police of Mu¨nster and in all emergency units of the six hospitals in Mu¨nster. A systematic acquisition of technical data from the police and the medical data from the hospitals were combined anonymously. Not every bicycle accident results in injury or is recorded by the police. Therefore a simultaneous and complete recording of data became necessary. The data were collected from three different sources: 1. Voluntary patient report 2. Police accident report 3. Hospital health record The forms did not contain any personal data of patients involved. The study was approved by the Ethical Committee of the University of Mu¨nster. The anonymous forms contained only patient age and gender as well as time, and place of bicycle accidents to match the
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Table 1 Distribution of questionnaires. n
Questionnaire Patient
Hospital
Police
Yes Yes
Yes Yes
Yes Yes
Yes Yes
Yes Yes Yes Yes
221 327 979 484 16 29 194
questionnaires. The data were entered into a central database (MS Access for input/MySQL for data retrieval). Results In the one-year study period, a total of 2250 patients suffered from an injury caused by a bicycle accident. Out of these 2250 patients, 484 were reported only by the police but did not show up in an emergency care unit. A police record did not exist for 1527 (67.9%) patients who were admitted to an emergency care unit (Table 1). For the remaining 239 patients documented in a hospital record or patient report, a police report was available as well. The typical injured bicyclist in Mu¨nster was between 19 and 29 years of age. Additional peaks could be observed around the age 50 and 70. When comparing the age distribution of the injured bicyclists to the age distribution of the Mu¨nster population, the age groups 10–19 and 20–29 were stronger represented in the injury group (Fig. 1). Each accident with a known cause was classified in one of the following groups: Technical bicycle defect Collision with other bicyclists Collision with motorised vehicle (car/truck/bus) Collision with fixed object Collision with motorcycle Collision with pedestrian Fall without external force/third party involvement (included falls because of ice, bad road conditions, etc.) Other (specified)
Fig. 1. Distribution of age-comparison.
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Fig. 2. Age and accident types.
The age distributions for the two most common accident types also differ. Elderly patients as well as very young children were more prominent in the ‘‘fall without external force/third party involvement’’ group. The ‘‘collision with motorised vehicle’’ group was dominated by patients between 20 and 29 years old (Fig. 2). During the course of the study period, car collisions were evenly distributed. Falls without external force were more common in late spring/early summer (Fig. 3). Most bicycle accidents were reported to the police in July, August, and November. In reality, however, most accidents happened in May (325 accidents). Only 20% of these accidents were reported to the police. Whilst the number of accidents was decreasing for the rest of the year, December showed a sudden increase. Since the weather in Germany in December, 2009 and January, 2010 was fairly similar, this cannot be explained by weather conditions alone. December is a month of many celebrations; therefore, an increased usage of bicycles instead of
cars due to alcohol consumption may also be a reason for the sudden increase in accidents (Fig. 4). Most accidents happened around 7 am and in the late afternoon, when bicycles are usually used to get to and from work (Fig. 5). Fractures were a frequent result of bicycle injuries (17.8% of all injuries), whereas only 4.5% of all patients suffered a traumatic brain injury (Fig. 6). The percentages refer to the total number of patients. Since one patient can have more than one injury, the total percentage sums up to more than 100%. Looking at how the location of all injuries (total number of injuries = 100%) was distributed, a different picture is revealed. Injuries to the head and skull were more common (25.7%) than the traumatic brain injury rate may suggest (Fig. 7). The mostly affected body regions were the extremities, with numbers of upper extremity injuries slightly exceeding the numbers of lower extremity injuries.
Fig. 3. Distribution of accident types over the year.
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Fig. 4. Number of reported cases: study vs. police.
The four main causes of accidents (collision with motorised vehicle, fall without external force, collision with fixed object, and collision with other bicyclist) showed different patterns of injuries. Traumatic brain injuries were more common in collisions with motor vehicles, whilst fractures of the upper extremities were the most frequent type of injury in the other accident causes (Table 2). Injury patterns were also related to age. Table 3 shows the age distribution of the patients in the study in absolute numbers. Number of fractures of the lower extremities increased with age (Fig. 8). Traumatic brain injuries were a frequent injury amongst those of age 60 and older (Fig. 9). In addition, fractures of thorax and pelvis occurred more commonly in the elder population (Fig. 10). Helmets were only rarely used amongst the injured bicyclist. 8.4% of the injured bicyclists where helmet use was documented either by the police or by the patient were actually wearing a helmet. Relating to all injured bicyclists, only 6.4% were actually wearing a helmet. The rate of helmet use was comparable between those bicyclists who suffered a traumatic brain injury and those
who did not. However, amongst bicyclists wearing a helmet, only mild traumatic brain injury (as classified by the Department of Defence and Department of Veterans Affairs (2008), and Traumatic Brain Injury Task Force) was observed. 13 bicyclists, who suffered a moderate or severe TBI, did not wear helmets. However, no data on helmet use was available for a considerable number of injured bicyclists (Table 4). Looking at the occurrence of different types of accidents during daytime and at night, falls without external force happened more frequently during the night hours, whilst collisions with motorised vehicles happened mainly during the daytime (Fig. 11). The total economic loss for society sums up to 39 Million Euros, according to the standards of the German Federal Highway Research Institute (BASt).5 In order to assess to positive benefit of bicycle use for society we used the Health Economic Assessment Tool (HEAT) provided by the WHO.6 The positive value (due to decreased incidents of diseases caused by lack of physical activity) of bicycling in Mu¨nster was 77 million Euros. However, these numbers are not without discussion
Fig. 5. Hour of accident.
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Fig. 6. Type of injury.
Table 2 Frequency of TBI and fractures.
TBI Fracture Fracture Fracture Fracture Fracture Fracture Fracture
pelvis skull face upper extremity thorax lower extremity spine
Collision w car/bus/truck (n = 605, 100%)
Fall w/o external force (n = 609, 100%)
Collision w fixed object (n = 149, 100%)
Collision w other bicyclist (n = 155, 100%)
13% 0% 1% 3% 7% 2% 3% 3%
6% 0% 0% 3% 18% 2% 7% 1%
2% 2% 0% 6% 15% 0% 2% 1%
4% 0% 2% 5% 17% 3% 2% 1%
since the positive effect occurs only if bicyclists regularly drive longer distances. Discussion Combining medical and police data, this study systematically examined the causes of accidents and the medical consequences resulting from using bicycles in a major German city. In the period from February, 2009 through January, 2010, 2250 bicyclists involved in accidents resulting in injuries were reported in Mu¨nster. Since patients, who only reported to a family physician, were not included in the study, the actual number of accidents is likely even higher. Each day, an average of six bicycle accidents was
recorded by Mu¨nster hospitals and/or police. In the same period, only 723 bicycle accidents involving personal injury were recorded by the police. Of these patients, however, only 239 were treated in an emergency unit. The other accident victims (484) were presumed to have had visits with either a family doctor or a general practitioner and did not need to be treated in a hospital. In contrast, 1766 patients were treated as a result of a bicycle accident in a hospital in Mu¨nster. Of these patients, only 239 (13%) cases could be identified in police reports. During the period of study, 1527 patients had to be treated in an emergency unit but these accidents were not reported to the police. This represents an underreporting rate of 68% of all accidents resulting in hospital treatment. It is also possible that victims of bicycle accidents had visits with health professionals outside the hospitals. Therefore, the difference between the police-reported numbers and actual number of accidents might be even higher. One reason for this high level of unreported cases may be the nature of the accidents and the high proportion of accidents that did neither involve nor cause damage to a third party.7,8 Table 3 Age distribution in absolute numbers.
Fig. 7. Location of INJURY.
Age
n
0–9 10–19 20–29 30–39 40–49 50–59 60–69 70–79 >79
67 318 610 281 337 251 150 139 59
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Fig. 8. Injury type and age (I).
Fig. 9. Injury type and age (II).
The proportion of falls without external causes was 27%, nearly as high as the proportion of collisions with motor vehicles. In the cases attended by the police, the percentage of crashes without external cause was 2% whilst the percentage of collisions with motor vehicles was 70%. If one considers the proportion of police recorded accidents in the patients with falls without external cause, 98% were not reported to the police. On the other
Table 4 Traumatic brain injury and helmet use. TBI yes Helmet yes Helmet no Helmet – no data available Total
TBI no
Total
5 61 35
139 1607 503
144 1668 538
101
2149
2250
hand, in collisions with motor vehicles, 83% of all cases were recorded. Most bicycle accidents involving personal injury could be dealt with on an outpatient basis. Only 11.5% (251) of patients required hospitalisation. Altogether, these patients had to be treated for a total of 1260 days in a hospital, i.e., each day showed an average of more than three patients in inpatient treatment as a result of bicycle accidents. Amongst the patients admitted to hospital, three victims died because of their injuries. Of all hospitalised patients, 30% fell without external influence, and 20% suffered from a collision with another vehicle. For another 30%, no exact cause of injury was recorded. Since most of the accidents involving cars were reported by the police, it is highly likely that a great portion of the missing accidents causes were also falls without external forces. Looking at the impact of bicycle accidents in Mu¨nster from an economic perspective, the study period witnessed an economic
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Fig. 10. Injury type and age (III).
damage of more than 39 million Euros as a result of bicycle accidents. The largest part of these costs was caused by patients needing hospital treatment. Considering the age distribution of accident victims, in comparison to the age distribution of the population, a high number of accident victims were in the age group of 20–29 years. In this group (students), bicycle is the most commonly used means of transportation (50.0% of all trips). Bicycle use would decline with increasing age. Thus, 45–65 year-olds use bicycles only for 33.5% of all trips. Amongst patients involved in bicycle accidents, there was no difference in gender distribution. In the age group of 30–39, more men than women were susceptible to these accidents, whilst in the age group of over 70, more women fell victim to bicycle accidents. This also reflects the age distribution of the total population. Considering the nature of the accident and the age distribution, the event of a collision with a motor vehicle was observed primarily with the 20–29 year-olds. Regarding the fall without external causes, the elderly (over 60 years old) and younger (under 9 years old) patients were the most dominant. Other publication also showed that bicycle accidents are influenced by age.9 The chronological analysis of the accidents showed an accumulation of bicycle accidents in the spring and early summer,
especially for accidents without external forces. This might be attributed to not being used to biking. In contrast to the overall number of accidents, the police observed an increase during the summer months. This example is significant to the results of the current study. Whilst the current official statistics suggested an increase in accidents in the summer months, the actual increase was observed in the spring. Introducing measures to prevent accidents in the summer would therefore be too late. Instead, these measures should be introduced in the spring. Falls without external force were a common accident during the night hours. The mostly affected age group in this case was 20–29 year-olds, which leads to the assumption that many cyclists involved in accidents were riding home after partying. Furthermore, it is assumed that alcohol also had a serious influence. However, in most cases, no data on alcohol impairment were provided from either hospitals or patients. Only 144 of 2250 cases contained this type of data. Most cyclists suffered upper or lower extremity injuries.10 Traumatic brain injuries (TBI) occurred only in 101 accident victims (4.5%). The injury patterns depended both on the mechanisms of the accident as well as the age of the riders. In collisions with motor vehicles, 13% of all patients suffered a skull– brain trauma, whereas in accidents resulting from falling or colliding with fixed objects, fractures of upper extremities were more common. Age also influenced injury patterns, such as the increase in fractures of lower extremities. We observed an increase in skull–brain trauma and fractures of the upper extremity at age 20–29 years and over 70 years. Chest trauma was more common in older patients than in younger patients.8 Only 8.4% of all accident victims where data on helmet usage was available were documented as wearing helmets. Approximately 24% of cases did not contain data on helmet usage. Amongst patients, who suffered from brain injuries, only 3.4% were recorded as wearing helmets at the time of accident. Amongst cyclists not wearing helmets, the risk increased to 3.8%. However, 35% of these cases did not contain data on helmet usage; therefore, no reliable conclusion could be made regarding the protective effect of the helmet to prevent skull–brain trauma. Furthermore, only TBI’s of first degree were recorded in patients wearing helmets. 13 patients had a traumatic epidural, subdural, or subarachnoid haemorrhage, or a contusion of the brain (i.e., a TBI of
Fig. 11. Accident type: day vs. Night.
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degree II or III). Of these 13 patients, 3 did not wear a helmet, and the remaining cases provided no data on helmet use. This seems to reaffirm the current literature, proving the protective effect of wearing a helmet in regards to severe traumatic brain injury.12–16 One patient died from the effects of severe TBI, whereas the other two patients died from the severity of other injuries and probably would not have survived even with a helmet. In authors’ opinion, riding bicycle is one of the healthiest and most environmentally friendly means of transportation.11 The positive health effect of bicycle riding is widely accepted. The WHO even offers a tool with which the positive economic effect (due to reduction of diabetes, coronary heart disease, etc.) of cycling can be calculated. Thus, the effect on Mu¨nster was determined to be about 77 million Euros.6 Unfortunately, bicycle is currently one of the most dangerous types of transportation in Mu¨nster. 2250 cyclists were injured during the time of this study, which is three times higher as in previous statistics. A loss of over 39 million Euros was taken into account, not considering the damage to property. Reasonable and sustainable transport measures should be taken into consideration in order to increase the safety of bicycle riding.10 Whilst car drivers are protected by rapid technological advances, cyclists do not have the equivalents of deformable zones and airbags. Moreover, personal protective equipment, such as a helmet, is often not used. Cycling is also a very inexpensive form of transportation. Whilst to some a bicycle is some type of a high-tech sports equipment, for others it is simply a healthy means of transportation. Unlike other means of transportation, it is missing a mandatory periodic review regarding the technical condition, since some accidents happen due to technical deficiencies.17
conclusion, that bicycle legislation can increase helmet use and decrease head injuries. They also could not support the thesis that a helmet legislation may lead to a decrease in bicycle use, as some reports from Australia suggested. Yet the evidence they found was not strong enough the either support or negate that thesis. The benefit of a bicycle helmet should be considered separately from the potential benefits of legally requiring bicycle helmet use. Whilst helmet laws may be beneficial, their introduction should be regarded critically, especially since bicycle helmets cannot prevent any accidents from happing. Thus other methods of prevention are needed as well. Preventive measures should be as specific for the target audience as possible. In the spring months, at the beginning of the cycling season, cyclists’ lack of exercise and drivers’ lack of adjustment may have contributed to an increase in accidents. Haileyesus19 identified a collision with a car as one of the most common accident type for cyclists in the USA that led to hospitalisation. These accidents occurred more often when cyclists had to share the road with motorised vehicles. He also concluded that prevention efforts should include improvement in the road environment along with the promotion of safe personal behaviour and practices. Preventive measures are necessary at the beginning of the cycling season in order to make both the cyclists and drivers more aware of the accident hazard. Many severely injured patients crashed on Friday and Saturday nights. There was also an increase in skull–brain trauma during this period. Mu¨nster is a city dominated by students as well as a city of short distances, making bicycles a common means of transportation. In this aspect it may differ from other cities of comparable size.
Conclusions
It is common for people to use their bicycles to ride home after a party, at which time alcohol is often involved. The legal alcohol limits allowed for car and bicycle use differ in Germany. Whilst a person is legally not allowed to drive a car with a blood alcohol level (BAC) exceeding 0.05% (BAC), bicycling is legally allowed with up to 0.16% (BAC). In other words, a person not considered fit to drive a car is allowed to use a bicycle. Looking at the high proportion of serious injuries that likely occurred under the influence of alcohol, the allowed alcohol levels for bicycling in Germany should be critically reconsidered. Whilst the drunken bicyclist does not so much pose a threat to other road users (as would be the case for a drunken car driver), he poses a great threat to his very own health. The high rate of people driving their bicycles under the influence of alcohol also shows a common attitude towards cycling. Cycling is more considered some kind of sport and fun than a means of transportation which should be dealt with as carefully as other means, such as cars. However, the idea not to drive a car under the influence of alcohol and use other means of transportation must be supported. In order to prevent people from using bicycles after drinking alcohol, alternative ways of transportation (such as public transport or the designated driver concept) must be promoted as well.
Our study showed that present statistics, based on police data, dramatically underestimate the actual number of bicycle accidents. Whilst previously we saw only the tip of the iceberg, this study allowed to look under the surface. Whilst cycling is one of the healthiest means of transportation, it is far more dangerous than assumed. Around 10% of all bicycle accidents lead to hospital stays. In Europe, the number of people killed in bicycle accidents is nearly the same as the number of people killed in motorcycle accidents. On a global scale, road traffic accidents and deaths have recently been termed an epidemic by the WHO. In order to implement effective prevention methods, the burden of these accidents – local and global – has to be understood. The burden of vulnerable road user deaths does not only differ geographically, but it also differs substantially amongst different income levels. There will be no global solution, but context-specific solutions will have to be identified.20 Bicycle helmets Despite of using three different sources to collect data, information on helmet usage were only available in 66.1% of all cases. Amongst those bicyclists, a helmet usage of 8.4% was documented. Due to the low helmet usage, no reliable conclusion could be made regarding the protective effect. However, the German Trauma Society recently published their recommendations for safer cycling. Wearing a helmet was one of the suggested measures. Macpherson and Spinks18 analysed the bicycle legislation for the uptake of helmet use and prevention of head injury. Five studies met their strict inclusion criteria. They came to the
Alcohol
Technical aspects Mu¨nster is a city with a large population of university students and high rate of bicycle theft. Thus especially students tend to use cheap and/or old bicycles because they cannot afford an expensive bicycle and are afraid such a bicycle might get stolen. These bikes sometimes have technical failures. 31 cyclists stated they fell from their bike because of technical defects.
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Whilst cycling in a city may not pose a larger stress for a bicycle and it materials, the new electric assisted bicycles (e-bikes or pedelecs) will have to deal with forces that so far only rarely occurred. The technical safety of these e-bikes must be considered carefully in the future to prevent an increase in accidents caused by technical failures.
Conflict of interest The authors declare that there are no financial and personal relationships with other people or organisations that could inappropriately influence (bias) their work.
The fear factor References Using a bicycle is still one of the healthiest and environment friendliest ways of transportation and should thus be promoted. The upcoming e-bikes can well be an alternative for a car or motorcycle for commuters with longer ways to work, helping to minimise air pollution. However, using a bicycle should be as safe as possible. One large threat to the health of a cyclist is the cyclist himself. Besides disregarding traffic laws (such as crossing a street on red, driving on the wrong side, etc.) is one of the main causes of bicycle collisions with other vehicles. Whilst hardly anybody would consider crossing a red light with a car, a lot of cyclists do so as soon as they feel ‘‘safe’’ to cross the street. There is a lack of awareness for the bicycle as mean of transportation which has its danger as any other. Whilst most motorcyclists will use personal protection and driving a motorcycle without such protection is considered dangerous by most people, a lot of bicyclists feel very safe using their bicycle without any protection. Still, an accident with a bicycle at 30 km/h can be regarded as equivalent to falling from a height of 3.6 m. A new awareness of cycling is needed that considers also the safety aspects of cycling. Whilst this awareness is not only needed for the individual cyclist, it is also needed for all traffic users. The danger of bicycling has been underestimated so far. Naci stated in his study that ‘‘context-appropriate and effective prevention strategies that protect the particular at-risk road user groups should be carefully investigated’’.20 Our study showed that only studies that take into account both clinical and police data can provide valuable results. Considering accidents registered only by the police provides an incomplete picture. However, we still lack a common collection of police and medical data. We can get a complete picture of what is happening on our roads only if we change the data collection method. Only then we can try to effectively implement specific prevention strategies. Role of the funding sources This study was funded by the German Insurance Association/ German Insurers Accident Research. The German Insurers Accident Research supported the scientific study design, analysis and interpretation of data from a technical perspective. The funding source was not involved in the collection and analysis of the data or in the interpretation of the data from a medical perspective. The joint authors’ decision to submit this paper was supported by the funding source.
1. Statistisches Bundesamt Deutschland: 70 million en ‘‘Drahtesel’’ werden in Deutschland gesattelt. Website: http://www.destatis.de/jetspeed/portal/cms/Sites/ destatis/Internet/DE/Presse/pm/zdw/2009/PD09__022__p002.psml (27.01.11). 2. Bundesministerium fu¨r Verkehr, Bau und Stadtentwicklung: Fahrradverkehr. Website: http://www.bmvbs.de/SharedDocs/DE/Artikel/SW/fahrradverkehr.html (26.01.11). 3. Martina Gu¨ttler, Stephan Bo¨hme, Dr Friedrich Wilhelm Oellers, Ute Kutschera. Fakten Fahrradhauptstadt Mu¨nster – Alle fahren Rad: gestern, heute, morgen. Stadt ¨ berarbeiMu¨nster, Stadtplanungsamt: Presse- und Informationsamt; 2009. U tete Neuauflage Ma¨rz. 4. Hautzinger H, Du¨rholt H, Ho¨rnstein E, Tassaux-Becker B. Dunkelziffer bei Unfa¨llen mit Personenschaden. Berichte der Bundesanstalt fu¨r Straßenwesen (M13); 1993. 5. Unfallkosten nach BASt. Website: http://www.bast.de/cln_015/nn_40694/DE/ Publikationen/Infos/2007-2006/02-2006.html (29.05.10). 6. World Health Organization. Transport and health: health economic assessment tool (HEAT) for cycling. Website: http://www.euro.who.int/en/what-we-do/ health-topics/environmental-health/Transport-and-health/publications2/pre2009/health-economic-assessment-tool-heat-for-cycling.-user-guide-2008. 7. Richter M, Otte D, Pape HC, Glueer S, Koenemann B, Tscherne H. Problematik der Verletzungen von Kindern und Jugendlichen im Straßenverkehr Eine medizinische und technische Unfallanalyse, der Unfallchirurg 2001;104(8):733–41. 8. Rivara FP, Thompson DC, Thompson RS. Epidemiology of bicycle injuries and risk factors for serious injury. Injury Prevention 1997;3(June (2)):110–4. PMID: 9213156 [PubMed – indexed for MEDLINE]. 9. Osberg JS, Stiles SC. Bicycle use and safety in Paris Boston and Amsterdam Transportation Quarterly Fall, vol. 52 (4). 1998. pp. 61–76. 10. Richter M. Verletzungen von Fahrradfahrern. Zeitschrift fu¨r Orthopa¨die 2005; 146(6): S. 604–605. doi:10.1055/s-2005-923493. 11. Wardlaw MJ. Three lessons for a better cycling future. BMJ 2000;321(December (7276)):1582–5. PMID: 11124188 [PubMed – indexed for MEDLINE]. 12. ECMT. Safety in road traffic for vulnerable users. Paris: Organisation for Economic Co-Operation and Development OECD; 2000M; European Road Safety Observatory Website: http://ec.europa.eu/transport/wcm/road_safety/erso/knowledge/Content/40_pedestrians/pros_and_cons_regarding_bicycle_helmet_legislation.htm (29.05.10). 13. Towner E, Dowswell T, Burkes M, Dickinson H, Towner J, Hayes M. Bicycle helmets: a review of their effectiveness, a critical review of the literature. Road safety research report no. 30. London: Department for Transport DfT; 2002 . 14. Thompson DC, Rivara FP, Thompson R. Helmets for preventing head and facial injuries in bicyclists. Cochrane Database Systematic Reviews 2005;4. 15. Robinson DL. Bicycle helmet legislation: can we reach a consensus? Accident Analysis and Prevention 2007;39:86–93. 16. Karkhaneh M, Kalenga J-C, Hagel BE, Rowe BH. Effectiveness of bicycle helmet legislation to increase helmet use: a systematic review. Injury Prevention 2006;12:76–82. 17. Andersen LB, Schnohr P, Scroll M, Hein HO. Mortality associated with physical activity in leisure time, at work, in sports and cycling to work. Archives of Internal Medicine 2000;160(June). 18. Macpherson A, Spinks A. Bicycle helmet legislation for the uptake of helmet use and prevention of head injuries (Review). The Cochrane Collaboration; 2009. 19. Haileyesus T, Annest JL, Dellinger AM. Cyclists injured while sharing the road with motor vehicles. Injury Prevention 2007;13:202–6. 20. Naci H, Chisholm D, Baker TD. Distribution of road traffic deaths by road user group: a global comparison. Injury Prevention 2009;15:55–9.
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Bicycle accidents – Do we only see the tip of the iceberg? A prospective multi-centre study in a large German city combining medical and police data C. Juhra a,*, B. Wiesko¨tter a, K. Chu a, L. Trost a, U. Weiss b, M. Messerschmidt b, A. Malczyk c, M. Heckwolf d, M. Raschke a a
University Hospital Mu¨nster, Department of Trauma-, Hand- and Reconstructive Surgery, Waldeyerstr. 1, D-48149 Mu¨nster, Germany Police Mu¨nster, Germany c German Insurance Association, German Insurers Accident Research, Germany d Mathias-Hospital, Rheine, Anaesthesiology Department, Germany b
A R T I C L E I N F O
A B S T R A C T
Article history: Accepted 16 October 2011
Introduction: Bicycles are becoming increasingly popular. In Mu¨nster, a German town with a population of 273,000, bicycles were the main method of transportation in 2009, used more often (37.8%) than cars (36.4%). Each day in Mu¨nster, bicycles are used around 450,000 times. In 1982, they were only used around 270,000 times a day. However, the increased use of bicycles has also led to an increased number of bicycle accidents. Methods: Between February 2009 and January 2010, data on bicycle-accidents leading to injuries were collected by the Police of Mu¨nster and in all emergency units of the six hospitals in Mu¨nster. A systematic acquisition of technical data from the police and the medical data from the hospitals were combined anonymously. None of the forms contained personal data of patients involved, except for patient age and sex as well as time and place of bicycle accidents to match the questionnaires. The data were entered into a central database (MS Access for input/MySQL for data retrieval). Results: 2250 patients were included in this study. For each of these patients either a patient record or a hospital record or a police record or a combination of any of these different records existed in our database. In total, 1767 patients received medical treatment at a hospital and 484 people included in the study did not go to a hospital. Three fatalities occurred as a result of bicycle accidents. Considering reasons for hospital admission, traumatic brain injuries were the leading cause (25.7%). However, the largest resource consumption was attributed to fractures of the upper extremities (36.8%) and lower extremities (29.9%) with major surgery. Discussion: Bicycle accidents occur more frequently than indicated by police records. The results of the Mu¨nster Bicycle Study have shown that the actual number of bicycle accidents exceeds the officially reported number by nearly two times. Since bicycle helmets cannot prevent accidents it is recommended not only to focus on helmet use as the only injury prevention method. Other factors, such as weather, pavement and default of traffic, roadworthiness of the bicycles or alcohol/drug abuse also affect the accident rates. ß 2011 Elsevier Ltd. All rights reserved.
Keywords: Bicycle accidents Traumatic brain injury Helmet Economic impact Fracture
Introduction Bicycles are becoming increasingly popular in Germany.1,2 The awareness of environmental issues, prices for gas, and an ever more mobile population are only some of the reasons for this. In Mu¨nster, a German town with a population of 273,000, bicycles were the main mode of transportation in 2009, used for trips more
* Corresponding author. Tel.: +49 251 83 56337, fax: +49 251 83 56318. E-mail address: [email protected] (C. Juhra). 0020–1383/$ – see front matter ß 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.injury.2011.10.016
often (37.8%) than the car (36.4%). The number of bicycles in Mu¨nster exceeds the number of the population by far (around 400,000 bicycles are owned by the 273,000 residents). Each day in Mu¨nster, bicycles are used around 450,000 times. In 1982 they were used only approximately 270,000 times a day.3 However, the increased use of bicycles has also led to an increased number of bicycle accidents. In 2009, according to police statistics, 1297 people were injured in traffic accidents in Mu¨nster, and nearly half of these victims (648) were involved in a bicycle accident. Three of these patients died because of their injuries.
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Whilst the number of recorded accidents is already high, the number of unrecorded cases is suspected to be even higher, as Hautzinger showed in a study on under-reporting of road traffic accidents in 1993.4 This is due to the nature of bicycle accidents, which often do not involve a third party or damage to property, hence rarely leading to the involvement of the police. If someone slips with his or her bike and falls, there is no reason for calling the police most of the time. If a high number of unreported cases exist, all which were previously known about bicycle accidents must be regarded with caution. Current knowledge on bicycle accidents is either gained by using clinical data alone or restricted to accidents recorded by the police. In order to obtain a realistic look at the bicycle accidents in Mu¨nster, the Mu¨nster police and all six hospitals in Mu¨nster with emergency departments reported all bicycle accidents with at least one injured cyclist over one year prospectively. We wanted to evaluate the actual number of bicycle accidents, the types and locations of these accidents, the use of protective gear such as a bicycle helmet, the type of bicycle used, the injury pattern and severity, the age distribution and the distribution of bicycle accidents over time. Materials and methods Between February 2009 and January 2010, data on bicycle accidents leading to injuries of cyclists were collected by the Police of Mu¨nster and in all emergency units of the six hospitals in Mu¨nster. A systematic acquisition of technical data from the police and the medical data from the hospitals were combined anonymously. Not every bicycle accident results in injury or is recorded by the police. Therefore a simultaneous and complete recording of data became necessary. The data were collected from three different sources: 1. Voluntary patient report 2. Police accident report 3. Hospital health record The forms did not contain any personal data of patients involved. The study was approved by the Ethical Committee of the University of Mu¨nster. The anonymous forms contained only patient age and gender as well as time, and place of bicycle accidents to match the
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Table 1 Distribution of questionnaires. n
Questionnaire Patient
Hospital
Police
Yes Yes
Yes Yes
Yes Yes
Yes Yes
Yes Yes Yes Yes
221 327 979 484 16 29 194
questionnaires. The data were entered into a central database (MS Access for input/MySQL for data retrieval). Results In the one-year study period, a total of 2250 patients suffered from an injury caused by a bicycle accident. Out of these 2250 patients, 484 were reported only by the police but did not show up in an emergency care unit. A police record did not exist for 1527 (67.9%) patients who were admitted to an emergency care unit (Table 1). For the remaining 239 patients documented in a hospital record or patient report, a police report was available as well. The typical injured bicyclist in Mu¨nster was between 19 and 29 years of age. Additional peaks could be observed around the age 50 and 70. When comparing the age distribution of the injured bicyclists to the age distribution of the Mu¨nster population, the age groups 10–19 and 20–29 were stronger represented in the injury group (Fig. 1). Each accident with a known cause was classified in one of the following groups: Technical bicycle defect Collision with other bicyclists Collision with motorised vehicle (car/truck/bus) Collision with fixed object Collision with motorcycle Collision with pedestrian Fall without external force/third party involvement (included falls because of ice, bad road conditions, etc.) Other (specified)
Fig. 1. Distribution of age-comparison.
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Fig. 2. Age and accident types.
The age distributions for the two most common accident types also differ. Elderly patients as well as very young children were more prominent in the ‘‘fall without external force/third party involvement’’ group. The ‘‘collision with motorised vehicle’’ group was dominated by patients between 20 and 29 years old (Fig. 2). During the course of the study period, car collisions were evenly distributed. Falls without external force were more common in late spring/early summer (Fig. 3). Most bicycle accidents were reported to the police in July, August, and November. In reality, however, most accidents happened in May (325 accidents). Only 20% of these accidents were reported to the police. Whilst the number of accidents was decreasing for the rest of the year, December showed a sudden increase. Since the weather in Germany in December, 2009 and January, 2010 was fairly similar, this cannot be explained by weather conditions alone. December is a month of many celebrations; therefore, an increased usage of bicycles instead of
cars due to alcohol consumption may also be a reason for the sudden increase in accidents (Fig. 4). Most accidents happened around 7 am and in the late afternoon, when bicycles are usually used to get to and from work (Fig. 5). Fractures were a frequent result of bicycle injuries (17.8% of all injuries), whereas only 4.5% of all patients suffered a traumatic brain injury (Fig. 6). The percentages refer to the total number of patients. Since one patient can have more than one injury, the total percentage sums up to more than 100%. Looking at how the location of all injuries (total number of injuries = 100%) was distributed, a different picture is revealed. Injuries to the head and skull were more common (25.7%) than the traumatic brain injury rate may suggest (Fig. 7). The mostly affected body regions were the extremities, with numbers of upper extremity injuries slightly exceeding the numbers of lower extremity injuries.
Fig. 3. Distribution of accident types over the year.
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Fig. 4. Number of reported cases: study vs. police.
The four main causes of accidents (collision with motorised vehicle, fall without external force, collision with fixed object, and collision with other bicyclist) showed different patterns of injuries. Traumatic brain injuries were more common in collisions with motor vehicles, whilst fractures of the upper extremities were the most frequent type of injury in the other accident causes (Table 2). Injury patterns were also related to age. Table 3 shows the age distribution of the patients in the study in absolute numbers. Number of fractures of the lower extremities increased with age (Fig. 8). Traumatic brain injuries were a frequent injury amongst those of age 60 and older (Fig. 9). In addition, fractures of thorax and pelvis occurred more commonly in the elder population (Fig. 10). Helmets were only rarely used amongst the injured bicyclist. 8.4% of the injured bicyclists where helmet use was documented either by the police or by the patient were actually wearing a helmet. Relating to all injured bicyclists, only 6.4% were actually wearing a helmet. The rate of helmet use was comparable between those bicyclists who suffered a traumatic brain injury and those
who did not. However, amongst bicyclists wearing a helmet, only mild traumatic brain injury (as classified by the Department of Defence and Department of Veterans Affairs (2008), and Traumatic Brain Injury Task Force) was observed. 13 bicyclists, who suffered a moderate or severe TBI, did not wear helmets. However, no data on helmet use was available for a considerable number of injured bicyclists (Table 4). Looking at the occurrence of different types of accidents during daytime and at night, falls without external force happened more frequently during the night hours, whilst collisions with motorised vehicles happened mainly during the daytime (Fig. 11). The total economic loss for society sums up to 39 Million Euros, according to the standards of the German Federal Highway Research Institute (BASt).5 In order to assess to positive benefit of bicycle use for society we used the Health Economic Assessment Tool (HEAT) provided by the WHO.6 The positive value (due to decreased incidents of diseases caused by lack of physical activity) of bicycling in Mu¨nster was 77 million Euros. However, these numbers are not without discussion
Fig. 5. Hour of accident.
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Fig. 6. Type of injury.
Table 2 Frequency of TBI and fractures.
TBI Fracture Fracture Fracture Fracture Fracture Fracture Fracture
pelvis skull face upper extremity thorax lower extremity spine
Collision w car/bus/truck (n = 605, 100%)
Fall w/o external force (n = 609, 100%)
Collision w fixed object (n = 149, 100%)
Collision w other bicyclist (n = 155, 100%)
13% 0% 1% 3% 7% 2% 3% 3%
6% 0% 0% 3% 18% 2% 7% 1%
2% 2% 0% 6% 15% 0% 2% 1%
4% 0% 2% 5% 17% 3% 2% 1%
since the positive effect occurs only if bicyclists regularly drive longer distances. Discussion Combining medical and police data, this study systematically examined the causes of accidents and the medical consequences resulting from using bicycles in a major German city. In the period from February, 2009 through January, 2010, 2250 bicyclists involved in accidents resulting in injuries were reported in Mu¨nster. Since patients, who only reported to a family physician, were not included in the study, the actual number of accidents is likely even higher. Each day, an average of six bicycle accidents was
recorded by Mu¨nster hospitals and/or police. In the same period, only 723 bicycle accidents involving personal injury were recorded by the police. Of these patients, however, only 239 were treated in an emergency unit. The other accident victims (484) were presumed to have had visits with either a family doctor or a general practitioner and did not need to be treated in a hospital. In contrast, 1766 patients were treated as a result of a bicycle accident in a hospital in Mu¨nster. Of these patients, only 239 (13%) cases could be identified in police reports. During the period of study, 1527 patients had to be treated in an emergency unit but these accidents were not reported to the police. This represents an underreporting rate of 68% of all accidents resulting in hospital treatment. It is also possible that victims of bicycle accidents had visits with health professionals outside the hospitals. Therefore, the difference between the police-reported numbers and actual number of accidents might be even higher. One reason for this high level of unreported cases may be the nature of the accidents and the high proportion of accidents that did neither involve nor cause damage to a third party.7,8 Table 3 Age distribution in absolute numbers.
Fig. 7. Location of INJURY.
Age
n
0–9 10–19 20–29 30–39 40–49 50–59 60–69 70–79 >79
67 318 610 281 337 251 150 139 59
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Fig. 8. Injury type and age (I).
Fig. 9. Injury type and age (II).
The proportion of falls without external causes was 27%, nearly as high as the proportion of collisions with motor vehicles. In the cases attended by the police, the percentage of crashes without external cause was 2% whilst the percentage of collisions with motor vehicles was 70%. If one considers the proportion of police recorded accidents in the patients with falls without external cause, 98% were not reported to the police. On the other
Table 4 Traumatic brain injury and helmet use. TBI yes Helmet yes Helmet no Helmet – no data available Total
TBI no
Total
5 61 35
139 1607 503
144 1668 538
101
2149
2250
hand, in collisions with motor vehicles, 83% of all cases were recorded. Most bicycle accidents involving personal injury could be dealt with on an outpatient basis. Only 11.5% (251) of patients required hospitalisation. Altogether, these patients had to be treated for a total of 1260 days in a hospital, i.e., each day showed an average of more than three patients in inpatient treatment as a result of bicycle accidents. Amongst the patients admitted to hospital, three victims died because of their injuries. Of all hospitalised patients, 30% fell without external influence, and 20% suffered from a collision with another vehicle. For another 30%, no exact cause of injury was recorded. Since most of the accidents involving cars were reported by the police, it is highly likely that a great portion of the missing accidents causes were also falls without external forces. Looking at the impact of bicycle accidents in Mu¨nster from an economic perspective, the study period witnessed an economic
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Fig. 10. Injury type and age (III).
damage of more than 39 million Euros as a result of bicycle accidents. The largest part of these costs was caused by patients needing hospital treatment. Considering the age distribution of accident victims, in comparison to the age distribution of the population, a high number of accident victims were in the age group of 20–29 years. In this group (students), bicycle is the most commonly used means of transportation (50.0% of all trips). Bicycle use would decline with increasing age. Thus, 45–65 year-olds use bicycles only for 33.5% of all trips. Amongst patients involved in bicycle accidents, there was no difference in gender distribution. In the age group of 30–39, more men than women were susceptible to these accidents, whilst in the age group of over 70, more women fell victim to bicycle accidents. This also reflects the age distribution of the total population. Considering the nature of the accident and the age distribution, the event of a collision with a motor vehicle was observed primarily with the 20–29 year-olds. Regarding the fall without external causes, the elderly (over 60 years old) and younger (under 9 years old) patients were the most dominant. Other publication also showed that bicycle accidents are influenced by age.9 The chronological analysis of the accidents showed an accumulation of bicycle accidents in the spring and early summer,
especially for accidents without external forces. This might be attributed to not being used to biking. In contrast to the overall number of accidents, the police observed an increase during the summer months. This example is significant to the results of the current study. Whilst the current official statistics suggested an increase in accidents in the summer months, the actual increase was observed in the spring. Introducing measures to prevent accidents in the summer would therefore be too late. Instead, these measures should be introduced in the spring. Falls without external force were a common accident during the night hours. The mostly affected age group in this case was 20–29 year-olds, which leads to the assumption that many cyclists involved in accidents were riding home after partying. Furthermore, it is assumed that alcohol also had a serious influence. However, in most cases, no data on alcohol impairment were provided from either hospitals or patients. Only 144 of 2250 cases contained this type of data. Most cyclists suffered upper or lower extremity injuries.10 Traumatic brain injuries (TBI) occurred only in 101 accident victims (4.5%). The injury patterns depended both on the mechanisms of the accident as well as the age of the riders. In collisions with motor vehicles, 13% of all patients suffered a skull– brain trauma, whereas in accidents resulting from falling or colliding with fixed objects, fractures of upper extremities were more common. Age also influenced injury patterns, such as the increase in fractures of lower extremities. We observed an increase in skull–brain trauma and fractures of the upper extremity at age 20–29 years and over 70 years. Chest trauma was more common in older patients than in younger patients.8 Only 8.4% of all accident victims where data on helmet usage was available were documented as wearing helmets. Approximately 24% of cases did not contain data on helmet usage. Amongst patients, who suffered from brain injuries, only 3.4% were recorded as wearing helmets at the time of accident. Amongst cyclists not wearing helmets, the risk increased to 3.8%. However, 35% of these cases did not contain data on helmet usage; therefore, no reliable conclusion could be made regarding the protective effect of the helmet to prevent skull–brain trauma. Furthermore, only TBI’s of first degree were recorded in patients wearing helmets. 13 patients had a traumatic epidural, subdural, or subarachnoid haemorrhage, or a contusion of the brain (i.e., a TBI of
Fig. 11. Accident type: day vs. Night.
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degree II or III). Of these 13 patients, 3 did not wear a helmet, and the remaining cases provided no data on helmet use. This seems to reaffirm the current literature, proving the protective effect of wearing a helmet in regards to severe traumatic brain injury.12–16 One patient died from the effects of severe TBI, whereas the other two patients died from the severity of other injuries and probably would not have survived even with a helmet. In authors’ opinion, riding bicycle is one of the healthiest and most environmentally friendly means of transportation.11 The positive health effect of bicycle riding is widely accepted. The WHO even offers a tool with which the positive economic effect (due to reduction of diabetes, coronary heart disease, etc.) of cycling can be calculated. Thus, the effect on Mu¨nster was determined to be about 77 million Euros.6 Unfortunately, bicycle is currently one of the most dangerous types of transportation in Mu¨nster. 2250 cyclists were injured during the time of this study, which is three times higher as in previous statistics. A loss of over 39 million Euros was taken into account, not considering the damage to property. Reasonable and sustainable transport measures should be taken into consideration in order to increase the safety of bicycle riding.10 Whilst car drivers are protected by rapid technological advances, cyclists do not have the equivalents of deformable zones and airbags. Moreover, personal protective equipment, such as a helmet, is often not used. Cycling is also a very inexpensive form of transportation. Whilst to some a bicycle is some type of a high-tech sports equipment, for others it is simply a healthy means of transportation. Unlike other means of transportation, it is missing a mandatory periodic review regarding the technical condition, since some accidents happen due to technical deficiencies.17
conclusion, that bicycle legislation can increase helmet use and decrease head injuries. They also could not support the thesis that a helmet legislation may lead to a decrease in bicycle use, as some reports from Australia suggested. Yet the evidence they found was not strong enough the either support or negate that thesis. The benefit of a bicycle helmet should be considered separately from the potential benefits of legally requiring bicycle helmet use. Whilst helmet laws may be beneficial, their introduction should be regarded critically, especially since bicycle helmets cannot prevent any accidents from happing. Thus other methods of prevention are needed as well. Preventive measures should be as specific for the target audience as possible. In the spring months, at the beginning of the cycling season, cyclists’ lack of exercise and drivers’ lack of adjustment may have contributed to an increase in accidents. Haileyesus19 identified a collision with a car as one of the most common accident type for cyclists in the USA that led to hospitalisation. These accidents occurred more often when cyclists had to share the road with motorised vehicles. He also concluded that prevention efforts should include improvement in the road environment along with the promotion of safe personal behaviour and practices. Preventive measures are necessary at the beginning of the cycling season in order to make both the cyclists and drivers more aware of the accident hazard. Many severely injured patients crashed on Friday and Saturday nights. There was also an increase in skull–brain trauma during this period. Mu¨nster is a city dominated by students as well as a city of short distances, making bicycles a common means of transportation. In this aspect it may differ from other cities of comparable size.
Conclusions
It is common for people to use their bicycles to ride home after a party, at which time alcohol is often involved. The legal alcohol limits allowed for car and bicycle use differ in Germany. Whilst a person is legally not allowed to drive a car with a blood alcohol level (BAC) exceeding 0.05% (BAC), bicycling is legally allowed with up to 0.16% (BAC). In other words, a person not considered fit to drive a car is allowed to use a bicycle. Looking at the high proportion of serious injuries that likely occurred under the influence of alcohol, the allowed alcohol levels for bicycling in Germany should be critically reconsidered. Whilst the drunken bicyclist does not so much pose a threat to other road users (as would be the case for a drunken car driver), he poses a great threat to his very own health. The high rate of people driving their bicycles under the influence of alcohol also shows a common attitude towards cycling. Cycling is more considered some kind of sport and fun than a means of transportation which should be dealt with as carefully as other means, such as cars. However, the idea not to drive a car under the influence of alcohol and use other means of transportation must be supported. In order to prevent people from using bicycles after drinking alcohol, alternative ways of transportation (such as public transport or the designated driver concept) must be promoted as well.
Our study showed that present statistics, based on police data, dramatically underestimate the actual number of bicycle accidents. Whilst previously we saw only the tip of the iceberg, this study allowed to look under the surface. Whilst cycling is one of the healthiest means of transportation, it is far more dangerous than assumed. Around 10% of all bicycle accidents lead to hospital stays. In Europe, the number of people killed in bicycle accidents is nearly the same as the number of people killed in motorcycle accidents. On a global scale, road traffic accidents and deaths have recently been termed an epidemic by the WHO. In order to implement effective prevention methods, the burden of these accidents – local and global – has to be understood. The burden of vulnerable road user deaths does not only differ geographically, but it also differs substantially amongst different income levels. There will be no global solution, but context-specific solutions will have to be identified.20 Bicycle helmets Despite of using three different sources to collect data, information on helmet usage were only available in 66.1% of all cases. Amongst those bicyclists, a helmet usage of 8.4% was documented. Due to the low helmet usage, no reliable conclusion could be made regarding the protective effect. However, the German Trauma Society recently published their recommendations for safer cycling. Wearing a helmet was one of the suggested measures. Macpherson and Spinks18 analysed the bicycle legislation for the uptake of helmet use and prevention of head injury. Five studies met their strict inclusion criteria. They came to the
Alcohol
Technical aspects Mu¨nster is a city with a large population of university students and high rate of bicycle theft. Thus especially students tend to use cheap and/or old bicycles because they cannot afford an expensive bicycle and are afraid such a bicycle might get stolen. These bikes sometimes have technical failures. 31 cyclists stated they fell from their bike because of technical defects.
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Whilst cycling in a city may not pose a larger stress for a bicycle and it materials, the new electric assisted bicycles (e-bikes or pedelecs) will have to deal with forces that so far only rarely occurred. The technical safety of these e-bikes must be considered carefully in the future to prevent an increase in accidents caused by technical failures.
Conflict of interest The authors declare that there are no financial and personal relationships with other people or organisations that could inappropriately influence (bias) their work.
The fear factor References Using a bicycle is still one of the healthiest and environment friendliest ways of transportation and should thus be promoted. The upcoming e-bikes can well be an alternative for a car or motorcycle for commuters with longer ways to work, helping to minimise air pollution. However, using a bicycle should be as safe as possible. One large threat to the health of a cyclist is the cyclist himself. Besides disregarding traffic laws (such as crossing a street on red, driving on the wrong side, etc.) is one of the main causes of bicycle collisions with other vehicles. Whilst hardly anybody would consider crossing a red light with a car, a lot of cyclists do so as soon as they feel ‘‘safe’’ to cross the street. There is a lack of awareness for the bicycle as mean of transportation which has its danger as any other. Whilst most motorcyclists will use personal protection and driving a motorcycle without such protection is considered dangerous by most people, a lot of bicyclists feel very safe using their bicycle without any protection. Still, an accident with a bicycle at 30 km/h can be regarded as equivalent to falling from a height of 3.6 m. A new awareness of cycling is needed that considers also the safety aspects of cycling. Whilst this awareness is not only needed for the individual cyclist, it is also needed for all traffic users. The danger of bicycling has been underestimated so far. Naci stated in his study that ‘‘context-appropriate and effective prevention strategies that protect the particular at-risk road user groups should be carefully investigated’’.20 Our study showed that only studies that take into account both clinical and police data can provide valuable results. Considering accidents registered only by the police provides an incomplete picture. However, we still lack a common collection of police and medical data. We can get a complete picture of what is happening on our roads only if we change the data collection method. Only then we can try to effectively implement specific prevention strategies. Role of the funding sources This study was funded by the German Insurance Association/ German Insurers Accident Research. The German Insurers Accident Research supported the scientific study design, analysis and interpretation of data from a technical perspective. The funding source was not involved in the collection and analysis of the data or in the interpretation of the data from a medical perspective. The joint authors’ decision to submit this paper was supported by the funding source.
1. Statistisches Bundesamt Deutschland: 70 million en ‘‘Drahtesel’’ werden in Deutschland gesattelt. Website: http://www.destatis.de/jetspeed/portal/cms/Sites/ destatis/Internet/DE/Presse/pm/zdw/2009/PD09__022__p002.psml (27.01.11). 2. Bundesministerium fu¨r Verkehr, Bau und Stadtentwicklung: Fahrradverkehr. Website: http://www.bmvbs.de/SharedDocs/DE/Artikel/SW/fahrradverkehr.html (26.01.11). 3. Martina Gu¨ttler, Stephan Bo¨hme, Dr Friedrich Wilhelm Oellers, Ute Kutschera. Fakten Fahrradhauptstadt Mu¨nster – Alle fahren Rad: gestern, heute, morgen. Stadt ¨ berarbeiMu¨nster, Stadtplanungsamt: Presse- und Informationsamt; 2009. U tete Neuauflage Ma¨rz. 4. Hautzinger H, Du¨rholt H, Ho¨rnstein E, Tassaux-Becker B. Dunkelziffer bei Unfa¨llen mit Personenschaden. Berichte der Bundesanstalt fu¨r Straßenwesen (M13); 1993. 5. Unfallkosten nach BASt. Website: http://www.bast.de/cln_015/nn_40694/DE/ Publikationen/Infos/2007-2006/02-2006.html (29.05.10). 6. World Health Organization. Transport and health: health economic assessment tool (HEAT) for cycling. Website: http://www.euro.who.int/en/what-we-do/ health-topics/environmental-health/Transport-and-health/publications2/pre2009/health-economic-assessment-tool-heat-for-cycling.-user-guide-2008. 7. Richter M, Otte D, Pape HC, Glueer S, Koenemann B, Tscherne H. Problematik der Verletzungen von Kindern und Jugendlichen im Straßenverkehr Eine medizinische und technische Unfallanalyse, der Unfallchirurg 2001;104(8):733–41. 8. Rivara FP, Thompson DC, Thompson RS. Epidemiology of bicycle injuries and risk factors for serious injury. Injury Prevention 1997;3(June (2)):110–4. PMID: 9213156 [PubMed – indexed for MEDLINE]. 9. Osberg JS, Stiles SC. Bicycle use and safety in Paris Boston and Amsterdam Transportation Quarterly Fall, vol. 52 (4). 1998. pp. 61–76. 10. Richter M. Verletzungen von Fahrradfahrern. Zeitschrift fu¨r Orthopa¨die 2005; 146(6): S. 604–605. doi:10.1055/s-2005-923493. 11. Wardlaw MJ. Three lessons for a better cycling future. BMJ 2000;321(December (7276)):1582–5. PMID: 11124188 [PubMed – indexed for MEDLINE]. 12. ECMT. Safety in road traffic for vulnerable users. Paris: Organisation for Economic Co-Operation and Development OECD; 2000M; European Road Safety Observatory Website: http://ec.europa.eu/transport/wcm/road_safety/erso/knowledge/Content/40_pedestrians/pros_and_cons_regarding_bicycle_helmet_legislation.htm (29.05.10). 13. Towner E, Dowswell T, Burkes M, Dickinson H, Towner J, Hayes M. Bicycle helmets: a review of their effectiveness, a critical review of the literature. Road safety research report no. 30. London: Department for Transport DfT; 2002 . 14. Thompson DC, Rivara FP, Thompson R. Helmets for preventing head and facial injuries in bicyclists. Cochrane Database Systematic Reviews 2005;4. 15. Robinson DL. Bicycle helmet legislation: can we reach a consensus? Accident Analysis and Prevention 2007;39:86–93. 16. Karkhaneh M, Kalenga J-C, Hagel BE, Rowe BH. Effectiveness of bicycle helmet legislation to increase helmet use: a systematic review. Injury Prevention 2006;12:76–82. 17. Andersen LB, Schnohr P, Scroll M, Hein HO. Mortality associated with physical activity in leisure time, at work, in sports and cycling to work. Archives of Internal Medicine 2000;160(June). 18. Macpherson A, Spinks A. Bicycle helmet legislation for the uptake of helmet use and prevention of head injuries (Review). The Cochrane Collaboration; 2009. 19. Haileyesus T, Annest JL, Dellinger AM. Cyclists injured while sharing the road with motor vehicles. Injury Prevention 2007;13:202–6. 20. Naci H, Chisholm D, Baker TD. Distribution of road traffic deaths by road user group: a global comparison. Injury Prevention 2009;15:55–9.