order to rationalize any health system, the aims, strategies and
health responsibilities should be defined. To improve the Health
Information Systems (HIS) and their use and to encourage health
workers to use them are two ways to achieve this purpose. According
to the WHO1,
a Health Information System is a structure for the collection, process,
analysis and transmission of the information needed to organize
and make health services work. In any HIS, the information collected
reflects the reality and it is the result of the data processing
that we need for a defined purpose2.
The aim of this article is the
description of a system of health information on road traffic injuries
in order to make it easy for the people responsible for collecting
the information, to assume the importance of their work in the information
process. The information presented in this article can be used for
any other information system by adapting it to different aims.
hypothetical information system presented here is about Traffic
The information of a SISLET comes from different sources. The design
of this system is based on some premises: the geographical unit,
the information needs and the people to whom it is addressed, the
database that should be created, the information needed, the sources
we should consult, the most effective backups, the statistical analysis
methods and the process of the information since it is collected
until it is made public. It is also necessary to take into account
the evaluation of the system in order to check its operational capacity4-9.
of a SISLET. Information systems have evolved because of the
increase of activity and the complexity of the assistance and registration
processes and the universalization of the new technologies. A SISLET
is an information system that processes information on people injured
in road accidents in a routine manner and by using different sources
that the system unifies and relates to get as much information as
possible about every injured person. It is a dynamic system that
can be modified according to information requirements.
basic character of a SISLET should be defined attending to the following
Degree of benefits obtained in ideal conditions.
Degree of beneficial effects when compared to the expected results,
in normal conditions.
Effects or results reached in relation to the effort made in terms
of money, time and resources.
Degree of precision and stability or consistency in the similarity
of the results in repeated measures.
Degree of similarity between the results and the reality of the
phenomenon we are studying10.
The Law about Personal Character Data Protection (LOPD) does not
allow people different from the researches to treat personal data,
so that they should be treated cautiously. Those violating this
law shall be punished.
The usefulness of a SISLET depends on whether right decisions can
be made or not taking the results as a starting point. If some mistakes
are made during the process, the estimation of the magnitude of
the problem can be wrong and it will have a later effect on the
preventive interventions designed afterwards, either exaggerating
them (useless increase on the health cost) or minimizing them (interventions
that do not reach the minimum required to be effective).
Aims of a SISLET
the priorities are established according to the health policy, the
aims should be pointed out, because establishing them beforehand
makes it easy to evaluate the results. The aims of a SISLET are
to monitorize the population in order to know the characteristics
of the group capable of getting hurt in road accidents (risk population),
to be aware of the dimension of the problem, the influencing factors,
the needs of health resources, the evaluation of the available resources
and their output and to spread the results in order to develop preventive
a SISLET. The measurements of any information system are those
of the frequencies used in epidemiology, such as the number of cases,
the reasons, the prevalence or the rates. Some of them are explained
in the following section.
The indicators are the measurements used in order to know the frequency
and the characteristics of the road accidents and their victims.
They shed some light on the magnitude of the problem and they allow
us to make predictions. The most important indicators in a register
of people injured in road accidents are the following:
Mortality indicators: The mortality measures the number of deaths
in a specific population and time. The indicators are either absolute
numbers or rates and they show the evolution in time of a specific
- Morbidity indicators: The
morbidity measures the number of people that fall ill (in this hypothetical
case, the number of people that get injured) in a specific population
and time. The indicators appear in terms of prevalence or incidence.
Prevalence: It represents the number of people that, in relation
to the total population, suffer an injury in a specific moment.
It considers the probability that a person sustains injuries in
a specific moment.
It considers the number of new cases that appear in a specific period
and the swiftness in which they happen. It represents the probability
and the speed in which the individuals of a population will get
injured during a specific period of time11.
of the sources of information of a SISLET. The information of
a SISLET comes from different sources but not all of them identify
the same groups of population and they are not equally accessible.
The figure 1 is a pyramid that presents the kind of people injured
according to different sources. They appear in decreasing order.
injured people that do not turn to the health service are only represented
in the health population survey.
The injured people treated in Primary health centres can be found
in the same Primary registers and in the health population survey.
who turn to Emergency services appear in the Emergency services,
061 (medical emergencies), fire brigade and police registers.
admitted to hospital appear on the hospital discharge register.
-Injured people who die can be
found in the Emergency services, 061, fire brigade, hospital discharge,
police, Forensic Institute and Mortality registers.
those with any kind of handicap because of the injuries can be represented
in any injured group, except in the one of the injured who die.
are some premises related to the information sources that a SIS
should consider as a starting point:
is useful but not essential to get personal details from all the
information sources so as to contrast the registers. If there is
no identifying data, registers can be related at random according
to the number of variables repeated in every register in the different
information sources: date of birth, date of the accident, date of
death, etc. It has to be taken into account that the same injured
person can appear in different registers.
information provided should be limited to a geographic zone, time
of the study and the causes of the injuries, according to the aims.
information sources are only valid when contrasting them12-13.
The different information sources being used for our information
system are analysed:
Mortality register. It considers the deaths caused by road traffic
injuries. It takes information from the Statistical Death Reports
(BED), where the cause of the death is established by the codes
of the International Classification of Diseases (ICD). There is
information about the number of deaths, the date and the cause.
It is useful because it is exhaustive and valid when talking about
the cause of the death. It is connected to the city register. It
also presents some limitations: it does not offer the circumstances
in which the accident took place and it does not say anything about
the time between the accident and death and about the place where
it happened. It just codifies the main cause of death.7,14-19
Discharge register. It offers the number of admissions to hospital
because of road traffic injuries. It specifies the kind, location
and seriousness of the injuries, the dates of admission and discharge,
and what happens with the patient afterwards (transfer, recovery,
death). Usefulness: it is a very important health source to evaluate
the impact of the road traffic injuries on the health of the population.
It describes the use of health services (hospitalization). Limitations:
it does not consider the injured who do not need to be admitted
to hospital, those who are transferred out of the geographic area
considered in the study or the deaths happening just after the accident.
It does not consider the circumstances or the place where the accident
Register of the Emergency services. It takes into account the emergency
medical care provided by the emergency services to those injured
in road accidents. It gives a report on the injured people who turn
to Emergency services and on the diagnosis and the seriousness of
the injuries. It offers information about the kind of user (driver,
passenger or pedestrian), about what happens with the patient (discharge,
admission, transfer, death.) and about the kind of vehicle (private
car, motorcycle, lorry, bus, bicycle), no matter whether we talk
about the vehicle used by the victim or the vehicle which has caused
the injuries (in order to specify, we will refer to "the position
with regard to the vehicle"). Usefulness: it gives information about
the injuries and about the use of health services. Limitations:
the death of those admitted to hospital and the deaths "in situ"
are not considered. It does not give any information about the circumstances
or the place where the accident took place. There may be some differences
in the thoroughness between the registers of different hospitals.
The injured people who receive any kind of treatment are the only
ones who appear.
4. Forensic Institute.
It considers the autopsies performed on road accident victims. Every
road accident involves a judicial process where the autopsy is required,
so that this source gives information about all road traffic deaths
occurred in the city, whatever the place of the accident, the address
of the dead person or the time between the crash and death. It gives
a report on the microscopy and macroscopic injuries and the cause
of death. It includes all deaths by accident in the city. Usefulness:
it is highly exhaustive and reliable. Limitations: the circumstances
and the place where the accident occurred are not always considered.26
Anatomical forensic clinic register. It gives a report on medical
tests which belong to people still alive that in this case concentrates
on health damages because of road accidents. It gives information
about the non mortal victims of road accidents who require judicial
intervention, medical surveillance and subsequent monitoring. It
also considers disabilities (any limitation or loss in the faculty
to carry out an activity inside the normal limits) and after-effects
(permanent disability). When disabilities are not permanent, it
gives information about the time needed for the recovery. Some expert
tests to check the ability of the patient are carried out. They
include assessment of the injuries, mental tests (disability statements,
disability and after-effects, evaluating the work ability in the
context of law, wrong medical praxis reports). Usefulness: it is
possible to determine the development of disabilities and their
after-effects. It also describes the injuries and it mentions the
hospital where the treatment was given as well as the number of
days of the injuries. All this information makes it possible to
carry out economic studies on road traffic injuries. Limitations:
there is no information about the circumstances in which the road
accident took place. People sustaining minor injuries and the place
where the accident happened are not taken into account.
Health survey. It considers the answers to questions about health
and healthy habits. The samples were chosen according to each survey
(women, young people, injured people, people chosen at random, etc.).
When well designed, it can be used to estimate the population prevalence
of road traffic injuries. On the one hand, it is the only instrument
that lets us know about the health felt and perceived by the patient.
Besides, it is the most effective method to get information about
the socioeconomic characteristics and the lifestyle of the patient.
On the other hand, it makes it possible to get information about
the disabilities of the population. Furthermore, it would be also
possible to learn about the consequences of health problems caused
by road traffic injuries as well as the physical and emotional effects
they have on the patients and their families that are not offered
by the mortality and morbidity rates. Usefulness: it considers injured
people treated or not by the health system. It gives information
about the disabilities and the use of services. Limitations: the
validity of the retrospective information is questionable because
of biased memory and because of the subjectivity in the answers.
In general health surveys there are usually just a few questions
about road traffic injuries.27-28
The fire brigade. Their register takes into account injured people
in serious accidents in which their help is required. They also
consider accidents in which people remain trapped in vehicles that
have lost their shape or those in which vehicles may set on fire
because of fuel leak or those already burnt. They give information
about the kind and seriousness of the injuries, health interventions
carried out, prognosis, place where the patient was transferred
and immediate deaths. Usefulness: quality technical health reports
with a good description of the injuries because the sanitary staff
is highly qualified. It gives information about the characteristics
of the road, the vehicle, the hospital in which the patient is admitted,
the assistance provided "in situ" and during the journey to hospital.
Limitations: the register only considers deaths and serious injuries.
People sustaining minor injuries and later deaths are not considered.
061-Medical emergencies. This register considers every person injured
in a road accident who requires assistance "in situ" or who needs
to be transferred to hospital. They provide assistance to every
injured person whatever the seriousness of their injuries, which
determines the kind of professional who comes to help (driver, nurse,
doctor). It offers information about the injuries, the prognosis,
medical assistance, place of the accident, kind of user and the
hospital where the patient was admitted. Usefulness: the information
is taken in the place of the accident. It takes into account immediate
deaths, injured people who required their assistance, the seriousness
of the injuries and the hospital where the patient was admitted.
Limitations: it is exclusively about sanitary information because
its aim is the stabilization of the patient so as to transfer him
quickly and in an adequate manner. People sustaining minor injuries
that do not require their assistance are not considered in the registers.
Later deaths are not considered either.
Police register. It offers information about all road accidents
in which police take part. It also explains the circumstances, the
mechanism and the place of the accident, the number, kind and model
of the vehicles involved, time and date, luminosity and kind of
light, state of the road, weather conditions, number, position and
condition of the injured people, place to which they were transferred,
material damage. Usefulness: it gives detailed information that
does not exist in other registers such as the detailed mechanism
and the circumstances in which the accident took place. Limitations:
it does not offer any information on the injuries. The prognosis
is not reliable for us because it is not issued by a health worker.
It includes death just for a period of 24 hours after the accident.
10. Primary care. This is the
register of the patients injured in road accidents who do not require
judicial intervention, but who require medical surveillance. The
GP evaluates the injuries and signs the medical certificate. This
register gives information about the injuries, the prognosis,
the development of the patient, the after-effects, the disabilities
and the dates of the beginning and end of the sick leave. Usefulness:
the fact that it considers the whole process makes it possible to
know about the time passed until the patient is discharged from
hospital and about the disabilities which become chronic. Limitations:
there is not a common register unifying the different primary care
centres. Injured people who do not need primary care services are
not considered. Immediate or later death in hospital is not considered.
It does not say anything about the circumstances in which the accident
happened and the position of the injured person.29
Phases of a SISLET
Spotting the problem: the fact that people injured in road accidents
are on the increase may cause alarm among the population and make
it necessary to define the problem.
Defining the aims: to know and to describe the magnitude and factors
of the problem and the characteristics of the group capable of getting
- Selecting the useful
information: to specify the information and the period of time we
are going to consider them.
Analysis of the information sources available. Sources of information
which are unreliable, incomplete, biased or difficult to gain access
to are dismissed.
information: the methodology and the instruments used through this
process should be systematized and unified for all the centres.
The methodology should be systematic and exhaustive. It is important
for people taking part in this process to be trained before and
to know about the usefulness of the register.
Data storage: creating database and input of information. It should
be done by the staff of the different centres or by the centre coordinating
- Quality check of the
database: the aim is to work towards the unification of criteria
between the sources of information, to spot mistakes and to determine
the validity and reliability of the information sources.
Analysis of the information: it is the most gratifying stage of
the whole circuit because it is at this point that we have the indicators
we were looking for since the beginning.30
Spreading the results: all the groups taking part in this process
should have access to the results, either the people who dealt with
the information or public health administrative staff.31
Evaluation of the SISLET: it would be done according to the aims
achieved and considering whether the cost higher or lower than planned.
the information sources
Sometimes, different sources of information mean different results.
If it is not clear, the methodology would be examined because different
methods may lead to different results, such as the mortality rate
and the final date to consider death, that may include or exclude
- There can be
different criteria and instruments such as differences in computer
systems that make it difficult the connection between different
data. People who design the information sources do not always consider
some aspects that can be negative for the researcher. That is because
the sources of information are usually designed attending to specific
needs that do not always coincide which those of an information
- There may be too much
information, some of it is not useful for the SISLET and it makes
it difficult to optimize the work.
There may be inadequate files catalogued and organized.
There may be questionable information and statements in terms of
validity and reliability.32-33
The source should be related to its context in order to understand
and solve the limitations by contrasting it with information form
different sources. This way, limitations should be detected.
Some limitations will not remain under the control of a SISLET and
we should make an effort in order to avoid the variability of the
results by implementing scientific methods when dealing with the
Finally, the final usefulness
of a SISLET may be questioned if it does not have any effect on
developed by the Public Health Agency of Barcelona (ASPB) since
1993 is an example of an Information System on Traffic Injured.
The sources of this system are Medical Emergencies, Road Accident
Reports by Barcelona Policeman, deaths reported by the Anatomical
Forensic Institute of Barcelona, the Mortality Register and the
Health Surveys of Catalonia. The aim of this project is to monitor
the magnitude and the characteristics of the people injured in road
accidents in the city of Barcelona. Seven public hospitals of the
city are currently participating in it. Documents on this issue
are available on the ASPB webpage: http://www.aspb.es/quefem/.
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