Optimal use of resources for the treatment
and prevention of injuries
Jon P Nicholl
Medical Care Research Unit, School of Health and Related Research, University of Sheffield,
Sheffield, UK
Injuries are an important cause of mortality and morbidity Although accidental
injury rates have been declining throughout the twentieth century in the UK,
this pattern has been variable. For example, in young adults aged 15-24 years
there has been no improvement and, when deliberate injuries are included, the
picture is worsening. Although there is little evidence that road traffic accident
case fatality rates have been improving, there is some evidence that
improvements in trauma care have been responsible for reducing injury death
rates in children. Thus, although there have been considerable successes in the
primary prevention of accidents, and the secondary prevention of injuries in
accidents, there is an important role for tertiary prevention, that is in the
prevention of avoidable outcomes through good trauma care.
Injury is reported as being currently responsible for 7% of world
mortality1. However, the proportion of deaths attributable to injury
vanes considerably between western countries such as the US (6.6%),
the UK (3.1%), France (8.7%), Germany (4.6%) and Canada (6A%)2
with the lowest reported proportion in The Netherlands (2.5%)3.
Although these proportions are small, injuries remain an area of very
great importance for several reasons. For example:
1 They are the leading cause of death in children (aged > 1 year),
adolescents, and young adults.
2 Deaths from injury account for 8.3% of all potential years of life lost
under the age of 75 in the UK4, and they are reported as accounting for
15% of all healthy years of life lost world-wide1.
Correspondence to
Prof. Jon P Nicholl,
Medical Care Research
Unit School of Health
and Related Research,
University of Sheffield,
Regent Court 30 Regent
St Sheffield S1 ADA. UK
3 In the UK, the incidence of serious injury and death exhibits a steep social
class gradient which is widening in children5.
4 Non-fatal injuries lead to significant disability in the population6.
5 They account for 7% of all NHS expenditure in the UK4, and 12% of all
medical spending in the US7.
British Medical Bulletin 1999, 55 (No 4) 713-725
C The British Council 1999
Trauma
The importance of injuries to death and ill health might make them a
primary target for national efforts to improve health. However, it is the
fact that many injuries are preventable which has underlined their
importance in national and international health programmes, and there
have been considerable successes in preventing injury mortality. Between
1980 and 1994, western countries reported reductions of between 20%
and 35% in their age/sex standardised mortality rates2. This improvement
is part of a longer-term trend. Although it has been reported3 that there
have been only 'minor changes in overall injury mortality over the entire
past century', this is not true in the UK, where, during the 20th century,
age standardised accidental death rates fell by 63% in men and by 52%
in women8.
This overall picture also hides considerable variations. In the UK,
spectacular gains have been made in childhood accident mortality, but
there has been little change in accidental mortality for youths aged 15-24
years8, and adding in non-accidental mortality from homicide and suicide
(which has been increasing in this age group in recent years9) means that
the death rate from injury in this age group has worsened. In order to
understand how these patterns may have come about and the role of
optimal trauma care, it is necessary to understand something about the
epidemiology of injury, and the nature of prevention.
It is, therefore, necessary to distinguish both between intentional
(homicidal, suicidal) and unintentional (accidental) injuries, and also
between prevention of the occurrence of the injuries and prevention of
the outcomes of injuries by optimal trauma care. These two aspects of
epidemiology and prevention are discussed in more detail below.
Finally, injuries and their optimal care must be understood in the
context of their costs, and this chapter concludes with a discussion of the
economics of injuries and different approaches to 'prevention'.
Epidemiology
Fatal injuries
Injuries arise from three groups of causes: (i) accidents; (ii) suicide and
deliberate self-harm; and (iii) assault and homicide. From the point of
view of prevention, the group of injuries and deaths from accidental
causes could also usefully be broken down according to their predictability, and hence primary preventability (see below). Unfortunately,
predictability is usually not quantifiable, and instead accidents are usually
classified by their type, place of occurrence, and other circumstances
which may be related to their predictability.
714
British Medical Bulletin 1999, 55 (No 4)
Optimal use of resources for treatment and prevention of injuries
Table 1 Deaths and hospital admissions for injuries, poisoning, and violence England and
Wales 1993/94
Deaths 1994
Hospital episodes 1993/94
n
(%)
Accidents
Transport
Road traffic accident
Other transport
Falls
Fire and flames
Drowning and submersion
Poisoning
39,671
2,545
3,327
131
3,402
167,833
2,681
395
672
948
484
30,078
Other
3,224
All known accidents
12,099
(75 2)
374,747
(83 5)
Deliberate self harm
3,619
(22 5)
52,823
(118)
373
(2 3)
21,451
(4 7)
Assaults
131,455
Not recorded
Total
212,972
16,091
(100)
661,993
In England and Wales, accidents account for three-quarters of all trauma
deaths, suicide for 23% and homicides for 2.3% (Table I)9. This is in sharp
contrast to the US, where 15% of all injury deaths are due to homicide7.
In many western countries, however, suicides are the most important single
cause of trauma deaths and they cause more deaths than road traffic
accidents or other causes of unintentional injury death2 (Table 1).
Accidents, suicides and homicides all show a distinct age pattern with
trauma deaths being particularly common in men, and especially in
younger men for all three causes (Fig. 1).
In women, most trauma deaths occur in the elderly (aged > 75 years)
and result from falls. However, interpretation of data about deaths
resulting from falls in the elderly is complicated by the fact that many of
these deaths result only indirectly from the fall, especially in the case of
falls resulting in fracture of the neck of femur. The direct cause of death
in these cases may be a condition such as bronchopneumonia following
a period of hospitalisation. Some coroners record these as deaths from
falls, others do not. For this reason, the numbers of deaths from falls
and trends and comparisons are difficult to interpret8.
Non-fatal injuries
Epidemiological data on non-fatal injuries are more limited. However, in
England and Wales, hospital episode statistics (HES) data record all
British Medical Bulletin 1999, 55 (No 4)
715
Trauma
Transport accidents
Men
Women
2400
2400
• 0-14
015-44
2000
B 45-79
1600
Q75+
0-14
2000
15-44
1600
145-79
Q75+
1200
1200
800
600
400 •
400
0
0
15-44
45-79
Age
Non-transport accidents
2400
• 0-14
2000
E515-44
m 45-79
1600
m
m
1200
D75+
1
HUH
800
400
0
0-14
15-44
45-79
75+
Age
Suicides
2400
2400 -•
T
015-44
2000
1600
1200 800400
0
• 0-14
• 0-14
E15-44
2000-
• 45-79
1600 -
Lk,
15-J4
45-79
• 75+
1200 -•
800 -•
400
0
15-44
75+
45-79
Ago
Age
Homicides
2400
2400 2000 •
2000 -
• 45-79
O45-79
1600
1600 ••
D75+
D75+
1200 ••
1200 •
800 800
Fig. 1 Deaths from
injury poisoning and 400
violence. England
and Wales 1993
°
and 1994.
716
400 ••
0-14
15-44
15-44
45-79
75+
45-79
Age
British Medical Bulletin 1999; 55 (No. 4)
Optimal use of resources for treatment and prevention of injuries
hospital admissions for injuries and poisonings and their ICD codes. The
external cause codes, however, are only recorded in about 40% of
episodes. Nevertheless, for those episodes where the external cause is
recorded, falls are by far the most frequent cause of admission (Table 1)
representing 37% of all recorded admission episodes, with deliberate selfharm (12%), road accidents (9%) and poisonings (7%) making up the
bulk of the remainder.
There is a much smaller difference between men and women in the
number of trauma admissions than in the number of trauma deaths (Fig.
2a). Furthermore, the age distribution shows two characteristic differences. Firstly, whilst death from injury in childhood is a proportionately
rare event, hospital admission is not. Secondly, whilst the elderly make
up the bulk of deaths in women and have the highest per capita rates of
hospital admission (Fig 2b), it is young women who make up the
majority of admissions (Fig 2a).
These differences mean that if we calculate the case fatality ratios, that
is the ratio of deaths to hospital admissions, some surprising patterns are
observed (Fig. 2c). For example, there are many times fewer deaths per
admission in young children than in adults, and there are three times
fewer deaths in young women admitted to hospital with injuries than in
young men. There are several possible explanations for this, such as
different admission thresholds, other differences in the severity distribution of patients admitted perhaps due to a difference in type of incident leading to admission; differences in the capacity of post-admission
trauma care to successfully resuscitate, and so on.
It seems most likely that the reasons for the differences in case fatality
ratios include different thresholds for admitting children, and different
case-mix for young women versus young men, but little or no difference
in the effectiveness of post-trauma care.
Timing of injury incidents
One further feature of the epidemiology of trauma is important in
understanding the role of trauma services and trauma care, and this is
the timing of incidents and deaths. In the UK, about 70% of major
trauma occurs out-of-hours or at weekends10'11 and over half of major
trauma cases die before reaching hospital10"12. Thus, the organisation of
in-hours hospital based trauma services should not be the primary focus
for the development of trauma services. Pre-hospital and out-of-hours
services should receive attention first.
Excluding catastrophic injuries leading to inevitable death at the scene
in a few minutes, there are three principal classes of cause of death13:
1 Immediate death typically resulting from airway obstruction or other
respiratory impediment, often resulting from trauma but including deaths
British Medical Bulletin 1999, 55 (No 4)
717
Trauma
Hospital admission episodes
160000 j
140000 -120000 100000 -•
80000
6000040000 20000
0-14
75+
Hospital admission episodes per 103 persons
D
50 -
•
40-
• Males
m Females
30 20
10 00-14
Im I\ ,I•
15-44
45-74
1
1 , m.
75+
Age
C Injury deaths per 1000 hospital admission episodes
Fig. 2 Hospital
admission episodes
for injury poisoning
and violence.
718
0-14
15-44
British Medical Bulletin 1999; 55 (No. 4)
Optimal use of resources for treatment and prevention of injuries
from asphyxiation due to drowning, hanging and so forth, leading to death
within minutes often at the scene and probably sometimes preventable14.
2 Early death typically from exsanguination, resulting from uncontrolled
haemorrhage, usually within an hour or two of multiple blunt injuries
resulting in fractures, organ rupture and vascular injuries.
3 Late death often from traumatic brain injuries, sepsis, or multiple organ
fadure, leadmg to death within days or weeks. These deaths may also be
preventable by earlier, better treatment15.
These three phases of traumatic death are important partly because of
how they have shaped emergency services. Historically, it has been
reported that the three types of death lead to a trimodal time of death
distribution16, with the second modal peak at 1—4 h post incident. It is
this observation that has led to the notion of the 'golden-hour', and the
focus of EMS on getting patients to definitive care within this period.
Recent studies have suggested, however, that though there may be three
principal phases in traumatic deaths this does not necessarily lead to a
trimodal distribution13'17*18. Indeed, studies which have examined the
relationship between prehospital times have usually failed to find any
simple monotonic relationship19"21, though one study has reported that
prehospital times in excess of one hour are associated with higher
mortality22. Unfortunately, the direction of cause and effect was unclear
(high risk of death leads to long prehospital times or vice-versa).
On balance, and bearing in mind the confusion of this evidence, the
truth is probably that, in most major trauma patients, all intervals of time
matter from the incident to definitive care in theatre: the early minutes14;
the time to arrival of care at the scene23; the prehospital time22; time in
resuscitation and the Accident and Emergency Unit20; and time to
theatre24'25. Unfortunately, there is little empirical evidence to indicate
which is the decisive phase. The weight of evidence suggests that it is the
total time to definitive care which matters more than the individual
phases. However, for certain groups of patients such as those with
penetrating injuries, drownings, or those with single system blunt trauma
head injuries, different phases may be more or less important. This points
up the more general fact that appropriate services depend on the nature of
any major trauma as much as on the fact that it is major trauma.
Prevention
It is useful to consider prevention under three headings:
1 Primary - the prevention of incidents which might lead to injury.
2 Secondary - the prevention of injury in incidents which do happen.
3 Tertiary -the prevention of the (health) consequences of injuries which
occur in those incidents which do happen by appropriate treatment.
British Medical Bulletin 1999, 55 (No 4)
719
Trauma
For both primary and secondary accident prevention, initiatives usually
come under one of three headings: (i) engineering, whether of products or
the environment; (n) enforcement, usually through regulation or
legislation; and (iii) education, often in the form of training.
For the prevention of deliberate harm it may also be helpful to
distinguish primary prevention of the conditions which give rise to
homicidal and suicidal attempts, secondary prevention via controlling
the availability or hazardousness of the means of committing deliberate
harm, and tertiary prevention of the outcomes of injury.
Primary prevention
The prevention of injury incidents depends on reducing the exposure to
risk, and this can be achieved either by reducing the frequency with which
a hazardous activity is undertaken, or by reducing the hazardousness of
each occasion of activity. Thus, for example, introducing regulations
requiring the wearmg of cycle helmets (a secondary prevention initiative)
appears to have had the effect of reducing the amount of cycling, as well
as reducing the risk of a head injury m an accident which does occur26.
Similarly, research on introducing road humps into residential areas to
slow traffic speeds found that some of the benefit was achieved only
through a reduction m the amount of traffic in the area27*28. Some of the
traffic, and hence accidents, was merely diverted to neighbouring areas
without humps. However, overall, important benefits were achieved.
Primary accident prevention is often most successful, therefore, when
it reduces the hazardousness of the environment or activity without
reducing the amount of the activity (usually termed 'exposure'). There
have been numerous product and environmental engineering successes
in primary prevention for vehicles, roads, lighting, swimming pool
fencing, child-resistant medicine packaging, and so on.
Enforcement has also been successful, and, for example, the introduction of vehicle speed cameras has been shown to have had dramatic
effects on accident rates29. Indeed one review of adolescent and youth
accidents suggested that of all the available strategies enforcement
seemed to offer the most likely future benefits26. However, the greatest
benefits may be achieved when education and enforcement come
together to create a cultural climate in which some hazardous behaviour,
such as drinking and driving, is 'prevented'. Education initiatives alone
are rarely successful.
With regard to non-accidental injuries, besides the criminal justice
system's contribution to primary prevention of assault and homicide
through deterrence and incarceration, there appear to be comparatively
few opportunities for primary prevention since the causes of homicidal
720
British Medical Bulletin 1999, 55 (No 4)
Optimal use of resources for treatment and prevention of injuries
and suicidal incidents may lie more in the realm of wider socio-economic
conditions. However, mental illness is undoubtedly a large contributing
risk factor for the occurrence of homicidal assault as well as for suicidal
deliberate self harm, and the care and control of mental illness could,
therefore, play a substantial part in this area of the primary prevention
of injury. Unfortunately, reviews have often concluded that attempts at
the primary prevention via our understanding of the relationship
between mental illness and suicide have failed30.
Secondary prevention
The prevention of injury in accidents which do occur is usually thought
of in terms of environmental and product engineering as in the case of
smoke alarms, seatbelts and airbags, and crash helmets. However, some
of the most important recent initiatives have been in the prevention of
injury in falls, which are the most common cause of non-fatal injury
events, and one of the most common causes of injury deaths. Secondary
prevention of injury in elderly people who fall can be achieved via the
prevention or slowing down of the rate of bone loss pharmacologically
(using hormone replacement therapy, or calcium and vitamin D
supplements, or bisphosphonates for example) or via weight-bearing
exercise. Mechanical injury prevention devices such as hip pads have
also been shown to reduce the chance of fractures m falls which do
occur31. Of course primary prevention initiatives through exercise and
muscle strengthening are also important32.
For intentional injuries, secondary prevention of injury or the severity of
injury via controlling access to or the hazardousness of the causes of
injury are also numerous and are likely to be effective. Although 'no single
intervention has been shown in a randomised controlled trial to reduce
suicide'33, it is widely accepted that secondary prevention measures such
as the replacement of town gas with natural gas, changing prescribing
rules for paracetamol, and gun and knife laws all have an effect on
deliberate harm. Certainly, we know that access to lethal weapons is a
significant risk factor for deliberate harm34-35 and restriction of that access
would seem, therefore, to be a significant preventive measure.
Tertiary prevention
The health outcomes of injury can also be prevented or ameliorated by
good trauma care. As well as questions about the evidence for therapeutic interventions, there are questions about what services should be
provided and how they should be organised. The basic principle is that
British Medical Bulletin 1999, 55 (No 4)
721
Trauma
the trauma care system should be organised to ensure that the minimum
possible time to reach definitive care in a treatable condition is achieved.
The trauma care system consists of several distinctive but integrated
phases which are sometimes described as making up a 'chain of survival':
these are first aid, prehospital care, transfer to hospital, hospital services,
and rehabilitation. Although there is a great deal of evidence about
effective therapeutic interventions in some of these phases at least, there is
less evidence about the cost-effectiveness of different services and modes
of organisation. One exception to this has been studies of the organisation
of hospital services for major trauma, where questions of the cost and
cost-effectiveness of trauma centres as well as their effectiveness have been
raised many times.
Relative benefits of different approaches to prevention
Although part of the reduction in the rate of death from injuries in the
20th century may be ascribed to tertiary prevention36, that is improvements in the medical care of the injured, the most important contributions
have probably come from primary and secondary prevention initiatives.
For example, whilst there has been a dramatic decline in the numbers of
deaths, and death rates, from road traffic accidents in the last 20 years,
the proportion of RTA casualties with serious injuries who died has
remained virtually unchanged8. To the extent that the definition and
recording of serious injury in police road accident statistics has remained
constant during this period, this unchanging proportion suggests that
there has been comparatively little improvement in tertiary prevention via
improvements in trauma care. For this reason, it is important that those
involved in providing trauma care should also be involved m injury
prevention.
Nevertheless, it would be wrong to conclude that this is where all efforts
should be placed. Even if most accidents are not 'accidents' but incidents
with clearly defined and preventable precursors, there are still large
numbers of accidents which will not or cannot be prevented as well as
growing numbers of episodes of deliberate harm. These episodes may be
less amenable to prevention than unintentional injury incidents. In these
cases, then, treatment rather than prevention may be the best public
health approach.
Costs and cost-effectiveness
The 1989 report to Congress on the cost of injury in the US estimated
that the aggregate life-time cost of 57 million persons injured in 1985
722
British Medical Bulletin 1999, 55 (No 4)
Optimal use of resources for treatment and prevention of injuries
was $158 billion37. These data have been updated to 1995 7 , and it is now
estimated that injuries cost the US economy $260 billion per annum
which equals that for cancer and heart disease combined. This is a cost of
approximately $1000 per person per year. This is particularly high, with
the costs in The Netherlands reported as $150-400 per person per year
depending on the method used for calculating the indirect costs of lost
production3. The direct treatment costs were estimated to be $100 per
person per year.
Despite the highest importance of injuries for both health and resources,
support for services remains relatively low, and the first issue which,
therefore, needs to be addressed is to increase the resources available for
injury care. But, if funding was available, where should it be directed? The
earlier discussion suggests that the principal effort should be put into
primary and secondary prevention, then into prehospital services for the
care of the injured, and lastly into hospital services. Again, however, the
rational approach has failed and most resources and organisational efforts
appear to be directed to re-organising hospital accident and emergency
services for trauma care.
Within hospital, a review of accident and emergency services which have
been shown to be both effective and affordable has been undertaken12. The
results of this study showed that m no case was there sound empirical
evidence on the costs of services for trauma care. Given the paucity of the
evidence from a cost-effectiveness point of view, the review was only able
to recommend with reasonable strength and unconditionally the use of
hospital trauma teams with ATLS training for the reception of major and
serious trauma.
Discussion
Injuries are a serious world-wide problem, and have been described as the
neglected disease of modern society. Injuries from road crashes kill 45,000
per year in the EU alone, and a further 3.5 million people are estimated to
be injured by them. The chaos, suffering, grief, pain, and distress which
can result from death and serious injury are almost incalculable. It is
difficult to estimate how much post-injury care can contribute to relieving
the burden of injury, but even if only a small fraction is avoidable the size
of the problem and the resources involved suggest that an increased level
of investment in the 'prevention' of this neglected disease would be
worthwhile. And yet compared to many other causes of epidemics of illhealth such as cancers, heart disease, and respiratory diseases, trauma care
is a poorly supported medical specialty. Why is this? One possible reason
is that the public and most policy-makers, as well as the medical
community, believe that dealing with injuries is primarily an issue for the
Brrtah Medical Bulletin 1999, 55 (No 4)
723
Trauma
primary and secondary prevention of incidents and injuries rather than
for post-incident injury care. It is, therefore, not seen as a medical
problem but rather as a social, political, or community problem. This
dismissive view may not be helped by those injury researchers who take
the view that unintentional injuries are never caused by 'accidents'
(which are the unpreventable acts-of-God) but by crashes, incidents,
events, and so on (which are the preventable acts-of-man). Thus, many
commentators no longer refer to road traffic accidents, for example, but
rather to road crashes. This language may be helping to erect further
barriers to involving the medical community in prevention. This would
certainly be an unwelcome effect if true, because the involvement of
trauma specialists in primary and secondary prevention, as well as the
tertiary prevention of the outcome of injury, is essential to the optimal
approach to reducing the burden of injury.
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