Whilst I agree with Nordstrom[1] about the clear research
opportunities in relation to headgear effectiveness for soccer players, I
would like to make a few comments.
Firstly, the issues raised are not just restricted to headgear use in
soccer – they apply equally well to many other sports, particularly other
football codes – and nor do they only apply to headgear use. Much of
sports safet...
Whilst I agree with Nordstrom[1] about the clear research
opportunities in relation to headgear effectiveness for soccer players, I
would like to make a few comments.
Firstly, the issues raised are not just restricted to headgear use in
soccer – they apply equally well to many other sports, particularly other
football codes – and nor do they only apply to headgear use. Much of
sports safety practice, including protective equipment (PE) use, is based
on common practice or best intent, and there are very few interventions at
all that have been formally evaluated through a randomised controlled
trial (RCT) design.[2]
Having said this, conducting RCTs for improving the evidence base for
sport PE effectiveness, is a major challenge in itself, particularly when
working with community-level or broad-based participation levels of play,
rather than highly competitive players. We attempted this sort of study
in Australian rules football. Headgear use is not widespread in this
sport, nor is there is evidence for its effectiveness yet there is
increasing pressure from parents and others to require junior players to
wear headgear. We attempted an RCT and randomised about 150 players to
wear headgear provided specifically for the purpose of the study.
However, fewer than seven players even attempted to wear the headgear
throughout the study, thereby negating any possibility of us assessing its
effectiveness in the field.[3] This was despite close monitoring and the
offering of significant incentives to players and teams who did wear the
headgear.
Finally, intervention studies in the sports injury context must work
within the culture of the sport and adopt strategies for maximising
desirable player behaviours. In the absence of high level support for an
item of protective equipment,[4] even the best designed evaluation trial
of the most optimally designed PE is due to fail. It is often stated, but
rarely substantiated, that players may believe that they tackle harder
because they feel safer when wearing PE,[5] and this adverse behaviour
change could increase overall injury rates. Those of us who work in the
sports injury area, will need to give very careful consideration towards
developing methodologies that will enable us to assess the effectiveness
of our interventions whilst still adjusting for, and working within, the
behavioural and social aspects of sports delivery. We will also need to
develop strategies to monitor any adverse changes in real on-field
behaviours as a result of this use.
References
1. Nordstrom DL. Sport safety research opportunity. Inj Prev 2004;10:255
2. Parkkari J, Mujala U, Kannus P. Is it possible to prevent sports
injuries? Review of controlled cinical trials and recommendations for
future work. Sports Medicine 2001;31(14):985-995.
3. Braham R, Finch C. Do community football players wear allocated
protective equipment? Results from a randomised controlled trial. Journal
of Science & Medicine in Sport 2004;7(2):216-220.
4. Braham R, Finch C, McIntosh A, McCrory P. Community football
players' attitudes towards protective equipment - a pre-season measure.
British Journal of Sports Medicine 2004;38:426-430.
5. Finch C, McIntosh A, McCrory P. What do under 15 year old
schoolboy rugby union players think about protective headgear? British
Journal of Sports Medicine 2001;35:89-94.
Franklin and Robinson are correct to question the complexity of the
evidence on helmet wearing among children.[1] As a brief report our paper was
unable to explore this in detail but we are grateful for the opportunity
to do so here.
The helmet wearing surveys suggested that helmet wearing fell among
children between 1994 and 1996.[2] Analysing accident data for the years
1995/96 alone shows a corresp...
Franklin and Robinson are correct to question the complexity of the
evidence on helmet wearing among children.[1] As a brief report our paper was
unable to explore this in detail but we are grateful for the opportunity
to do so here.
The helmet wearing surveys suggested that helmet wearing fell among
children between 1994 and 1996.[2] Analysing accident data for the years
1995/96 alone shows a corresponding increase in % head injuries (%HI).
This increase is not seen in adult data. From 1996 onwards helmet wearing
increased slightly and non-significantly among children and %HI remained
almost constant (figure 1).
Fig. 1 Head injury in child cyclists, 1995-2001
These trends need to be interpreted very cautiously, particularly the
sudden change in %HI in 1996. However, the suggestion is clearly that head
injury rates track helmet wearing closely and this was the conclusion that
we tried to summarise in our paper.[3] Franklin and Robinson examine
helmet-wearing rates in detail, but the sensational headline is premature
without the other half of the analysis - injury rates.
Raven also jumps to a premature conclusion.[4] His first mistake is to state
that we admit a fundamental error in our paper. Rather, we admitted an
arithmetic error in the discussion section of our paper that has no effect
on the main results and so can hardly be described as fundamental - a word
used only by Annan.[5] His reliance on Annans' letter and failure to pay
sufficient attention to our original paper also leads to a second mistake.
We estimated the reduction in head injuries among pedestrians and cyclists
from regression models, and gave 95% confidence intervals for each. A high
protective effect of helmets therefore remains consistent with these data.
References
1. Franklin J, Robinson D L. Another serious error in Cook & Sheikh's analysis [electronic response to Cook A and Sheikh. Trends in serious head injuries among English
cyclists and pedestrians] injuryprevention.com 2003 http://ip.bmjjournals.com/cgi/eletters/9/3/266#101
2. Bryan-Brown K, Christie N. Cycle helmet wearing in 1999. Transport
Research Laboratory Report 487, 2001.
3. Cook A, Sheikh A. Trends in serious head injuries among English
cyclists and pedestrians. Inj Prev 2003; 9: 266-267.
4. Raven T. Re: Authors' reply [electronic response to Cook A and Sheikh A. Trends in serious head injuries among English
cyclists and pedestrians] injuryprevention.com 2003 http://ip.bmjjournals.com/cgi/eletters/9/3/266#103
5. Annan J D. Fundamental error in "Trends in serious head injuries..." Cook and Sheikh 2003 [electronic response to Cook A and Sheikh A. Trends in serious head injuries among English
cyclists and pedestrians] injuryprevention.com 2003 http://ip.bmjjournals.com/cgi/eletters/9/3/266#59
Cook and Sheikh have accepted the fundamental error in their paper pointed out by Annan.[1-3]
When the arithmetic error is corrected there are only two conclusions
that can be reached. One, pointed out by Annan,[2] is that for every helmet
worn, two people are saved. This is clearly untenable and so the only
other conclusion, also pointed out by Annan,[2] is that there are other
factors invo...
Cook and Sheikh have accepted the fundamental error in their paper pointed out by Annan.[1-3]
When the arithmetic error is corrected there are only two conclusions
that can be reached. One, pointed out by Annan,[2] is that for every helmet
worn, two people are saved. This is clearly untenable and so the only
other conclusion, also pointed out by Annan,[2] is that there are other
factors involved in the reduction of head injuries. Without knowing what
these factors are, their magnitude and their sign, it is impossible to
reach any conclusion on whether helmet wearing increases, decreases or has
no effect on head injuries.
The authors' insistence that there is still a causal link[3] despite the
implications of correcting their arithmetic can only mean that they are
more interested in proving helmets improve safety than in researching
whether or not they improve safety.
References
1. Cook A, Sheikh A. Trends in serious head injuries among English cyclists and pedestrians. Inj Prev 2003; 9: 266-267.
2. Annan J D. Fundamental error in "Trends in serious head injuries..." Cook and Sheikh 2003 [electronic response to Cook and Sheikh. Trends in serious head injuries among English cyclists and pedestrians]injuryprevention.com 2003 http://ip.bmjjournals.com/cgi/eletters/9/3/266#59
3. Cook A, Sheikh A. Authors' reply [electronic response to Annan J D. Fundamental error in "Trends in serious head injuries..." Cook and Sheikh 2003] injuryprevention.com 2003 http://ip.bmjjournals.com/cgi/eletters/9/3/266#94
There is another serious problem with Cook and Sheikh's paper.[1] The
authors cite a TRL report [2] stating that, on major roads, helmet wearing (%HW)
increased from 16.0%, in 1994, to 17.6% in 1996 then 21.8% in 1999. The TRL
report continues: "this was due to an increase among adult cyclists
wearing helmets: there was no change amongst child cyclists."[2]
There is another serious problem with Cook and Sheikh's paper.[1] The
authors cite a TRL report [2] stating that, on major roads, helmet wearing (%HW)
increased from 16.0%, in 1994, to 17.6% in 1996 then 21.8% in 1999. The TRL
report continues: "this was due to an increase among adult cyclists
wearing helmets: there was no change amongst child cyclists."[2]
In fact, Table 3 shows %HW of girls was unchanged, but boys' %HW declined
steadily (16.0%, 13.3% and 12.7% in 1994, 1996 and 1999; c2=3.51, p=0.06, for 1994 vs 1999).[2] Another TRL survey
in 1999 found that child %HW was even lower on quieter roads, 9.7%.
Yet Cook and Sheikh reported almost identical declining trends in
percentages of UK hospital admissions with head injury (%HI) for adult
(8.09 percentage points) and child (8.32) cyclists, with more children (1625)
injured than adults (1129).[1] Most injured child riders are male; boys (75%
of child cyclists in the TRL surveys) ride more and also tend to take more
risks. The TRL surveys show boys' %HW was low and decreasing, and that,
overall, children's %HW fell from 17.6% in 1994 to 15.0% in 1999.
If Cook and Sheikh believe the fall in adult %HI was due to increased helmet
wearing, they must, logically, also believe the fall in children's %HI was due
to reduced %HW. Instead of campaigning for mandatory helmet laws, they'd call
for child helmets to be banned!
It's much more plausible that %HI of child and adult cyclists in the UK
followed similar trends (fairly similar to %HI trends in pedestrians), unrelated
to helmet wearing.[3] The most informative data on the efficacy of helmet laws
comes from Australia and New Zealand; large increases in %HW did not produce any
obvious response in %HI.[4]
Readers interested in reducing injuries to cyclists should therefore
consider proven measures such as traffic calming, cyclist and motorist
education, reducing the incidence of speeding and drink-driving,[4] and
encouraging people to cycle [5] as a popular, healthy, normal, everyday activity
that doesn’t need special equipment such as helmets.
References
(1) Cook A, Sheikh A. Trends in serious head injuries among English
cyclists and pedestrians. Inj Prev 2003; 9: 266-267.
(2) Bryan-Brown KCN. Cycle helmet wearing in 1999. Transport Research
Laboratory.
(3) Robinson D. Reasons for trends in cyclist injury data. Injury
Prevention 2004; 10: 126-127.
(4) Robinson DL. Head injuries and bicycle helmet laws. Accid Anal Prev
1996; 28: 463-475.
(5) Jacobsen PL. Safety in numbers: more walkers and bicyclists, safer
walking and bicycling. Inj Prev 2003; 9: 205-9.
I read the article by Shults et al with interest.[1] State driving under the influence of alcohol (DUI) countermeasures
[2] is a rational measure but one that has serious limitations including
the confounding influence of recreational drugs, carbon monoxide, other
environmental toxins, medications and cerebrovascular diseases. The
immediate opportunity exists for implementing a far more rational an...
I read the article by Shults et al with interest.[1] State driving under the influence of alcohol (DUI) countermeasures
[2] is a rational measure but one that has serious limitations including
the confounding influence of recreational drugs, carbon monoxide, other
environmental toxins, medications and cerebrovascular diseases. The
immediate opportunity exists for implementing a far more rational and
effective measure. Optimally this would require making the passing of a
dedicated generic metabolic evaluation, combined with some form of
biometric identification of the driver, a pre-requistite for starting and
driving a car. The test could be enforced by law if the finding were also
to be recorded and the record made secure in a black box for recovery in
the event of an accident as in the airline industry.
What should be measured? I submit it is not a blood level of alcohol
or any other substance for blood levels are often dissociated from
cellular levels and the cellular effects of two or more drugs,
medications, carbon monoxide, other environmental toxins and
cerebrovascular diseases might be additive. An additonal variable is
genetically determined and acquired alterations in enzymatic activity and
hence cellular responses to these potential perturbations. It may well be
that dietary composition of both immediate and distant past meals is
another important variable for metabolic rather than absorptive reasons.
The cognitive, behavioural and functional disturbances induced by alcohol
can, therefore, be expected to vary greatly within and between individuals
with the same blood alcohol level. Those within legal limits could be
impaired and those above legal limits not.
The best measurement to make might be the intramucosal pH which may
be conveniently derived from an indirect measurement of pCO2 in the mouth
[4,5] and the arterial bicarbonate [6] or a suitable non-invasive surrogate
possibly even salivary bicarbonate. The direct measurement of sublingual
pH might even be the most suitable measurement. What makes the measurement
particularly attractive in this context is that there are good reasons to
believe that significant metabolic impairments detectable from changes in
pH might be the primary cause of avoidable accidents be they the product
of behavioural, cognitive or functional disorders.
A fall in intramucosal pH in the stomach, which has been used to
validate the sublingual measurements, is of establised predicitive value for
organ dysfunctions be they the product of alcohol, recreational drugs,
medications, myocardial infarction, dehydration, haemorrhage and/or the
systemic inflammatory response syndrome. An additional advantage of this
measurement, which could easily be repeated if a driver were to feel
unwell, would be the very early detection of serious organic disease. This
would give the driver the opportunity to stop and call for help. The
measurement might even be made continuously and linked to a hotline.
Microsensors such as the ISFET [7] and the Paratrend [8] have already
been developed that might be conveniently and inexpensively adapted for
this purpose. Before deciding whether to adopt this proposal to prevent
accidents it will, however, be necessary to perform a prospective
randomised study to establish the predictive value of these measurements
for accidents. In so doing violent behaviour could be conveniently
included as an additional end-point.[9]
References
(1) Shults R A, Sleet D A, Elder R W, Ryan G W, Sehgal M. Association between state level drinking and driving countermeasures and self reported alcohol impaired driving. Inj Prev 2002 Jun;8:106-10.
(2) Fiddian-Green R G. Delgardonian psychocivilising of the armed forces? [electronic response to Knox K L et al. Risk of suicide and related adverse outcomes after exposure to a suicide prevention programme in the US Air Force: cohort study] bmj.com 2003 URL direct link to eLetter
(3) Fiddian-Green R G. Psychiatric aspects: an energy deficit? [electronic response to Wasserberg J. Treating head injuries] bmj.com 2002 URL direct link to eLetter
(4) Marik PE, Bankov A. Sublingual capnometry versus traditional
markers of tissue oxygenation in critically ill patients.
Crit Care Med 2003 Mar;31(3):818-22.
(6) Fiddian-Green RG. Worshipping false gods; A call to worship a new god, tissue pH; pH regulation of ATP synthase activity: evolutionary biochemical bedrock?; pH dependence of protein synthesis and cachexia; Nutrient supply dependency and the lactate shuttle hypothesis [electronic responses to Dantzker D R. Monitoring Tissue Oxygenation: The Quest Continues] Chestjournal.org 2001 URL direct link to eLetters
(7) Inoue H, Tsuchida M, Takano Y, Sato I, Sato Y, Ikegami K,
Sekiguchi T, Nagai Y. Assessment of peripheral blood perfusion during open
heart surgery with sublingual PCO2 measured by ISFET-PCO2 sensor.
Masui 2002 Oct;51(10):1155-65.
(8) Light TD, Jeng JC, Jain AK, Jablonski KA, Kim DE, Phillips TM,
Rizzo AG, Jordan MH. The 2003 Carl A Moyer Award: real-time metabolic
monitors, ischemia-reperfusion, titration endpoints, and ultraprecise burn
resuscitation.
J Burn Care Rehabil 2004 Jan-Feb;25(1):33-44.
(9) Fiddian-Green R G. A public health project worthy of massive public funding provided
the aim is not to screen for "mental illnesses" [electronic response to Lenzer J. Bush plans to screen whole US population for mental illness] BMJ 2004 URL direct link to eLetter.
We are grateful to Annan for spotting the arithmetic error in the
discussion section of our paper of trends in cyclist head injuries.[1] It
would be a mistake, however, to allow a minor mistake in the discussion to
divert attention from the main finding of the paper, which was that
cyclist head injuries fell during a time of increased helmet wearing.
Population level time trend studies are limited in the am...
We are grateful to Annan for spotting the arithmetic error in the
discussion section of our paper of trends in cyclist head injuries.[1] It
would be a mistake, however, to allow a minor mistake in the discussion to
divert attention from the main finding of the paper, which was that
cyclist head injuries fell during a time of increased helmet wearing.
Population level time trend studies are limited in the amount of inference
that can be drawn directly from them, but they nonetheless remain a useful
strand of information that reinforces the findings of the case-control
studies[2] and other population studies[3] showing cycle helmets to be an
effective health intervention.
In response to the comments of Chapman,[4] the accident figures are
difficult to interpret since any comparison between the crude injury rates
of pedestrians and cyclists requires some denominator measure of how much
of each activity takes place. Chapman makes some interesting observations
about the high profile of cycling injuries, and it is indeed a shame that
cycling is perceived as a dangerous activity, but to suggest that
advocates of cycle helmets promote this fear is fallacious. We would also
like to point out that the assumption that those campaigning for cycle
helmets are not cyclists themselves is completely unfounded; one of us
(AC) is a highly experienced cycle tourist and commuter and a long-
standing member of the London Cycling Campaign. We also both encourage
our children to cycle – wearing helmets, of course!
References
(1) Annan JD. Fundamental error in "Trends in serious head injuries..." [electronic response to Cook A, Sheikh A. Trends in serious head injuries among English cyclists and pedestrians] injuryprevention.com 2004URL direct link to eLetter
(2) Thompson DC, Rivara FP, Thompson R. Helmets for preventing head
and facial injuries in bicyclists (Cochrane Review). In: The Cochrane
Library, Issue 2, 2004. Chichester: Wiley, 2004 [http://www.Cochrane.org]
(3) Macpherson A, To T, Macarthur C, Chipman M, Wright J, Parkin P.
Impact of mandatory helmet legislation on bicycle-related head injuries in
children: a population-based study. Pediatrics 2002;110:e60
(4) Chapman G. Cycle helmets: time for a reality check [electronic response to Cook A, Sheikh A. Trends in serious head injuries among English cyclists and pedestrians] [electronic response to Cook A, Sheikh A. injuryprevention.com 2004URL direct link to eLetter
To focus on injury mitigation in cyclists to the exclusion of
addressing the causes of crashes, as is the trend in public debate at
present,[1] risks fundamental errors - not least the post hoc fallacy of
assuming that cycling head injuries are the result of failure to wear
helmets, rather than of the types of crashes cyclists experience.
As a result of this obsession we have arrived at the ab...
To focus on injury mitigation in cyclists to the exclusion of
addressing the causes of crashes, as is the trend in public debate at
present,[1] risks fundamental errors - not least the post hoc fallacy of
assuming that cycling head injuries are the result of failure to wear
helmets, rather than of the types of crashes cyclists experience.
As a result of this obsession we have arrived at the absurd position
where the death of a child cyclist is publicly attributed not to the fact
that he rode off the pavement into traffic on a bike with defective
brakes, but to the fact that when he did so he was not wearing a helmet.
Recent analysis of Department of Health data on child hospital
admissions for England for the period 1995/96 to 2002/03[2] showed that:
the proportion of head injuries in child cyclists on the road is
hardly different from that of child pedestrians (49% against 46%, with
helmet wearing rates of 15%[3])
the risk of head injury in off-road cycling is an order of
magnitude lower than in road cycling;
cycling is far from being the leading cause of head injury
admission, being behind trips and falls and even assault.
Why is it, then, that cycling is seen as a uniquely dangerous
activity, when a dispassionate look at these and many other statistics
indicates very clearly that it is not? There are probably a number of
factors at work:
head injuries raise the spectre of intellectual disablement, which
of course cannot be "fixed" by modern medicine, even though this is very
rare - the fact that such injuries are now thought to be mainly the result
of rotational forces which helmets do not mitigate (and may even
aggravate) adds a touch of irony
even trivial head injuries can bleed spectacularly, which combined
with the fear factor, and justifiable anxiety over the cosmetic outcome,
increases the likelihood of attendance at A&E “just in case”, even
though in most cases treatment is limited to basic first aid - so that
nurses, for example, "see a lot of cycling head injuries";
there exists a substantial industry whose expensive product will
not sell unless a culture of fear is maintained, and the protective effect
of its product "sexed up" - few people would spend the price of a modern
helmet if they were told bluntly that they are tested only for the
equivalent of a fall from a stationary riding position, yet this is the
literal truth (note the wide disparity between claims made by
manufacturers and by helmet advocacy groups, who still quote as gospel the
flawed 1989 Thompson, Rivara and Thompson study,[4] despite well-
documented and acknowledged criticisms[5])
the culture of fear extends in particular to the danger of motor
traffic, with some justification as the estimated 10% of child cycling
which is on-road results in half of all child cyclist admissions and
almost all the deaths
there is a false belief that nothing can be done about the source
of this danger (i.e. drivers cannot be made to drive more carefully), and
no amount of riding skill can reduce the danger; but cycle trainers report
widespread ignorance of riding techniques which can avert many of the more
common sorts of crash[6], and surely only political will is lacking in
challenging driving behaviour
fundamentally, most of those campaigning for helmets are not
cyclists and have little understanding of the vast range of different
activities and scales of risk which that term encompasses - it is as if
all outdoor activity from afternoon walks in the park to free-climbing
were considered under a single umbrella.
There is a pressing need to return debate to the sources of danger,
and means of its reduction. Motor vehicles account for around a tenth of
child injury admissions but half of all injury fatalities[7]. This
increased risk is shared by cyclists, (far more numerous) pedestrians, and
motor vehicle occupants. The danger is inherent in the source, not the
victims’ activities, and no proper study of head injury in cyclists should
ignore this fact.
It is also time to recognise that opposition to helmet compulsion,
and to a lesser extent promotion, is not purely libertarian, but based on
robust evidence. As road safety minister David Jamieson recently
acknowledged, the Government knows of no case where cyclist safety has
improved with increasing helmet use. There can be no justification for the
continuing dominance of the cycle safety agenda by this single issue.
Most importantly, the principal indicator for cyclist safety is
numbers cycling.[8] By deterring participation,[9] helmet promotion may
actually reduce safety, in the name of mitigating a minority of those
injuries cyclists may experience.
Perhaps if we all slowed down and drove more carefully the perceived
need for helmets would evaporate - along with the terrible toll of road
traffic fatalities.
References
For example: 1. Sheikh A, Cook A, Ashcroft R. Journal of the Royal Society
of Medicine 2004;97:262-265
2. Data provided to CTC, the national cyclists’ organisation, by the
Department of Health
We thank Dr Carra for his comments[1] and we appreciate his attention
to
our work.[2]
Our paper was directed to a method for ranking potential safety
problems that merit additional statistical and engineering review. We
envisioned a surveillance process to develop a rank ordered problem list.
A follow-up review process should start at the top of the problem list
and work down through it,...
We thank Dr Carra for his comments[1] and we appreciate his attention
to
our work.[2]
Our paper was directed to a method for ranking potential safety
problems that merit additional statistical and engineering review. We
envisioned a surveillance process to develop a rank ordered problem list.
A follow-up review process should start at the top of the problem list
and work down through it, as resources permit. Problem ranking with
our proposed statistic minimizes the "false positives" issue as it pushes
these toward the bottom of the list. We understand this does not
eliminate the issue. The only way we know to do that with certainty is to
get rid of the surveillance.
We have never assumed that all relevant crash "factors" are coded
perfectly in FARS and we said so in our conclusions. Throughout
the paper, we also emphasized the relevance of this method to datasets
other than FARS.
Like any good diagnostic test, the proposed methodology should be
evaluated by a proven ability to detect a known issue early. That is why
we studied an acknowledged problem. The FARS data show other
potential issues of concern that were unknown, at least to us. See, for
example, the fatal vehicle fire data shown in Figure 4.
Dr. Carra's letter points out that the first data from the agency's
Early
Warning Reporting system has been received by NHTSA and are currently
being analyzed. The public may not be aware that these data for deaths,
injuries, and property damage are currently being withheld from public
health researchers outside the agency. As our paper points out, secret
data were an essential ingredient in the original tragedy and ensuing
scandal. This lesson seems not to have been learned.
Our proposed method to improve defect-related surveillance would have
worked well to identify the Ford Explorer tire problem as a high priority
concern for the agency. Our paper demonstrates this could have been
known long before so many deaths and injuries resulted. See Figure 1.
Reference
1. Carra J. Unwarranted Assumptions about FARS data [electronic response to Whitfield and Whitfield; Improving surveillance for
injuries
associated with potential motor vehicle safety defects] injuryprevention.com 2004http://ip.bmjjournals.com/cgi/eletters/10/2/88#74
2. R A Whitfield and A K Whitfield. Improving surveillance for
injuries
associated with potential motor vehicle safety defects. Inj Prev 2004; 10:88-92.
Our critics argue two points. First, they argue that
newspapers are an inappropriate source of data on
defensive gun use (DGU) because editors routinely
and deliberately suppress stories of legitimate DGU
that involve killing or wounding or firing at an adversary.
(Some of these writers also argue that brandishing a
gun in self-defense is even less likely to be reported in
the newspaper because these...
Our critics argue two points. First, they argue that
newspapers are an inappropriate source of data on
defensive gun use (DGU) because editors routinely
and deliberately suppress stories of legitimate DGU
that involve killing or wounding or firing at an adversary.
(Some of these writers also argue that brandishing a
gun in self-defense is even less likely to be reported in
the newspaper because these cases most often do not
even become known to police. However, this point is
irrelevant to our study because we only assessed DGU
killings, woundings, and firings.) It is incumbent on
these critics to provide the evidence to support their
claim. Merely citing examples (such as the case of
Peter Odighizuwa) where news stories left out mention
of a gun being used in self-defense is not enough.
They need to show that the degree of editorial bias is
enough to account for the results we found. In the
newspaper we used, the editors would have had to
have suppressed more than one story per day of DGU
killing or wounding that the police knew about (if Kleck
and Gertz’s [1] rates are accurate). When we began the
study we asked and were told that there was no
editorial policy not to print stories of DGU killings and
woundings. Because it is obvious that the newspaper
does not report all stories of woundings by gun, we
also asked specifically about stories involving citizens
wounding assailants in self-defense, and we were told
there would be “a high probability they would be
reported in the paper.” We checked the rate of DGU
killings reported in the newspaper and found it
compared favorably to the rate of justifiable homicides
in the Uniform Crime Report (there is no comparable
report of “justifiable woundings”). What these critics
need is data from the following kind of study: a survey
of the daily police operations reports to identify cases
that appear to be DGU, and a determination of the
percentage of those that are reported in the local
newspaper (not USA Today). We are not aware of any
such study, but would be happy to learn if one exists.
Second, they argue that we cannot establish the
true rate of DGU from newspaper reports. This point is
a strawman because nowhere in our paper do we
attempt to do so. Instead, we used newspaper reports
as a "reality check" on Kleck and Gertz’s rates, and
found that if their rates are accurate then 98% of the
DGU killings and woundings that the police knew about
went unreported in the newspaper. We leave it to
readers to decide which is more plausible, that Kleck
and Gertz’s rates are too high or that so many known
cases are kept out of the newspaper. Note that Kleck
and Gertz combine the categories of DGU killings and
DGU woundings. A very straightforward assessment of
the accuracy of their telephone survey would be to
separate out the rate of DGU killings and compare it to
the rate of justifiable homicides in the Uniform Crime
Report. We have asked Professor Kleck for this
breakdown and are awaiting his response.
Reference
1. Kleck G, Gertz,M. Armed resistence to crime: the
prevalence and nature of self-defense with a gun.
Journal of Criminal Law and Criminology 1995;86:150-
87.
IP is gaining a reputation in the cycling community as
a journal lacking in objectivity when it concerns the
effectiveness of bicycle helmets. Its past zealous
defence of flaws found in helmet research that IP has
published gives cause for concern.
Its latest silence over the identification of a
serious calculation error (Annan [1]) raises serious ethical questions
as well as doubts about...
IP is gaining a reputation in the cycling community as
a journal lacking in objectivity when it concerns the
effectiveness of bicycle helmets. Its past zealous
defence of flaws found in helmet research that IP has
published gives cause for concern.
Its latest silence over the identification of a
serious calculation error (Annan [1]) raises serious ethical questions
as well as doubts about the competence of IP's peer
reviewers.
Isn't it time to put the Editor's personal views on
bicycle helmets aside and let the science prevail even
if he doesn't like the outcomes?
1. Annan JD. Fundamental error in "Trends in serious head injuries..." Cook and Sheikh 2003 [electronic response to
Cook and A Sheikh; Trends in serious head injuries among English cyclists and pedestrians] injuryprevention.com 2004http://ip.bmjjournals.com/cgi/eletters/9/3/266#59
Dear Editor
Whilst I agree with Nordstrom[1] about the clear research opportunities in relation to headgear effectiveness for soccer players, I would like to make a few comments.
Firstly, the issues raised are not just restricted to headgear use in soccer – they apply equally well to many other sports, particularly other football codes – and nor do they only apply to headgear use. Much of sports safet...
Dear Editor
Franklin and Robinson are correct to question the complexity of the evidence on helmet wearing among children.[1] As a brief report our paper was unable to explore this in detail but we are grateful for the opportunity to do so here. The helmet wearing surveys suggested that helmet wearing fell among children between 1994 and 1996.[2] Analysing accident data for the years 1995/96 alone shows a corresp...
Dear Editor
Cook and Sheikh have accepted the fundamental error in their paper pointed out by Annan.[1-3]
When the arithmetic error is corrected there are only two conclusions that can be reached. One, pointed out by Annan,[2] is that for every helmet worn, two people are saved. This is clearly untenable and so the only other conclusion, also pointed out by Annan,[2] is that there are other factors invo...
Dear Editor
There is another serious problem with Cook and Sheikh's paper.[1] The authors cite a TRL report [2] stating that, on major roads, helmet wearing (%HW) increased from 16.0%, in 1994, to 17.6% in 1996 then 21.8% in 1999. The TRL report continues: "this was due to an increase among adult cyclists wearing helmets: there was no change amongst child cyclists."[2]
In fact, Table 3 shows %HW o...
I read the article by Shults et al with interest.[1] State driving under the influence of alcohol (DUI) countermeasures [2] is a rational measure but one that has serious limitations including the confounding influence of recreational drugs, carbon monoxide, other environmental toxins, medications and cerebrovascular diseases. The immediate opportunity exists for implementing a far more rational an...
We are grateful to Annan for spotting the arithmetic error in the discussion section of our paper of trends in cyclist head injuries.[1] It would be a mistake, however, to allow a minor mistake in the discussion to divert attention from the main finding of the paper, which was that cyclist head injuries fell during a time of increased helmet wearing. Population level time trend studies are limited in the am...
Dear Editor
To focus on injury mitigation in cyclists to the exclusion of addressing the causes of crashes, as is the trend in public debate at present,[1] risks fundamental errors - not least the post hoc fallacy of assuming that cycling head injuries are the result of failure to wear helmets, rather than of the types of crashes cyclists experience.
As a result of this obsession we have arrived at the ab...
Dear Editor
We thank Dr Carra for his comments[1] and we appreciate his attention to our work.[2]
Our paper was directed to a method for ranking potential safety problems that merit additional statistical and engineering review. We envisioned a surveillance process to develop a rank ordered problem list. A follow-up review process should start at the top of the problem list and work down through it,...
Dear Editor
Our critics argue two points. First, they argue that newspapers are an inappropriate source of data on defensive gun use (DGU) because editors routinely and deliberately suppress stories of legitimate DGU that involve killing or wounding or firing at an adversary. (Some of these writers also argue that brandishing a gun in self-defense is even less likely to be reported in the newspaper because these...
Dear Editor
IP is gaining a reputation in the cycling community as a journal lacking in objectivity when it concerns the effectiveness of bicycle helmets. Its past zealous defence of flaws found in helmet research that IP has published gives cause for concern.
Its latest silence over the identification of a serious calculation error (Annan [1]) raises serious ethical questions as well as doubts about...
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