—from Epidemiological
Bulletin , Vol. 25 No. 1, march 2004—
Deaths from Motor Vehicle Traffic Accidents*
in Selected Countries of the Americas, 1985-2001
Introduction
Deaths from road traffic injuries (RTI), and in particular Motor Vehicle Traffic
Accidents (MVTA) have been characterized worldwide as a hidden epidemic which
affects all sectors of society.1,2 An estimated 1.26 million people worldwide
died in 2000 from RTI, 90% of them in low and middle-income countries. In
2000, the road traffic injury mortality rate for the world was 20.8 per 100,000
population (30.8 in males, 11.0 in females). In the Americas, it was of 26.7
for males and 8.4 for females. The Americas bear 11% of the burden of road
traffic injury mortality.3 Globally traffic deaths and injuries on health
and society have an enormous cost estimated at around 1- 2% of a country’s
GNP in lower income countries2. The theme for this year’s World Health
Day (WHD), celebrated on 7 April, was Road Safety when the growing problem
of worldwide road traffic deaths and injuries was highlighted and a global
initiative on road safety and road traffic injury prevention presented. The
World Report on Road Traffic Injury Prevention4, published on the occasion
of WHD, presented a number of recommendations highlighted in Box 1.
In the Americas during 1997-2000, mortality from all land transport accidents
was the tenth leading cause of death in the general population, the 6th leading
cause in males with an annual average of registered deaths of 77,820 and the
16th in females, with 24,702 deaths5. The importance of the burden of death
from land transport accidents, especially among younger age groups, is further
noted in that they are the 2nd leading cause of potential years of life lost
(YPLL) to 75 years of age overall (annual average of 4.2 million years) and
in the male population (annual average of 3.2 million years) and 5th among
females (annual average of 1.0 million years) over the same period.
The objective of this paper is to present a brief overview of the situation
of MVTA in the Region of the Americas.
Methods
The full impact on the toll in human lives from motor vehicle accidents becomes
clearer when annual data are studied. Registered deaths from MVTA were analyzed
in 12 countries of the Americas during 1985-2001 – Argentina, Belize,
Brazil, Canada, Chile, Colombia, Cuba, Guatemala, Mexico, Puerto Rico, United
States and Venezuela. These countries were chosen for geographical and data
availability reasons. During this period, mortality was classified according
to the Ninth and Tenth Revisions of the International Classification of Diseases
(ICD) in all of these countries with the exception of Guatemala where ICD-9
only was used.
A motor vehicle is defined as any mechanically or electrically powered device
not operated on rails, and includes cars, buses, trucks, vans, motorcycles,
and off-road vehicles. A traffic accident is defined as any vehicle accident
occurring on a public road or highway and includes vehicle accidents where
the place of occurrence is unspecified. Non-traffic accidents are defined as
occurring entirely in any place other than a public highway. Motor vehicle
traffic accidents were assigned to categories E810-E819 in ICD-9 and to the
following categories in ICD-10: V02-V04 (.1-.9), V09.2, V09.3, V12-V14 (.3-.6),
V19 (.4-.6), V20-V28 (.3-.9), V29-V78 (.4-.9), V80 (.3-.5), V81.1, V82.1, V83-V86
(.0-.3), V87 (.0-.8), V89.2 and V89.9. In ICD-10, deaths from transport accidents
are assigned according to the type of vehicle in which the victim was an occupant
and then to the characteristics of the injured person – car or bus occupants,
pedestrian, motorcycle rider, pedal cyclist and whether the accident was traffic
or non-traffic. In ICD-9, however, the deaths were classified by the type of
vehicle involved in the accident – train, motor vehicle, watercraft,
and aircraft and whether the accident was traffic or non-traffic and then identifying
the injured person. Also, in ICD-10, the death must clearly indicate that a “motor” vehicle
was involved, whereas in ICD-9, the term “motor” did not have to
be specified. Accidents involving unspecified vehicles or where the victim’s
mode of transport in ICD-10 is unknown are classified as “Other land
transport accidents”. It should be noted that deaths assigned to cause
categories X59 in ICD-10 and to E887 and E928 may include “unspecified” deaths
involving motor vehicles and were not specified on the death certificate. As
a result of the coding changes in ICD-10, caution should be observed when comparing
mortality assigned to MVTA in both revisions. When available, comparability
ratios between ICD-9 and ICD-10 for MVTA should be used to help interpret the
data.
To analyze the data, proportionate mortality ratios and mortality rates were
used. Analyses were carried out by age and sex. Death rates were also standardized
by the direct method to allow comparisons between countries and periods.
Trends
Magnitude of the problem
In the selected countries, motor vehicle traffic accidents were the leading
cause of death in females from 5-14, 15-24, and 25-44 years of age accounting
for 15%, 18% and 7%, respectively, of all deaths from defined causes. They
were also the leading cause among males 5-14 years of age (19%) and the second
leading cause of deaths in males 15-24 (19%), and 25-44 years of age (12%).
Of the registered deaths from all external causes 1985-2001 in these 12 countries,
MVTA represents an average of around 20-30% in Brazil, Belize, Canada, Mexico,
Puerto Rico, and the United States, 32% in Venezuela and 6% in Guatemala. Of
the motor vehicle traffic accident deaths registered 1996-2001, pedestrians
account for 12% in Argentina, Canada and the United States, 20-30% in Colombia,
Cuba, Mexico, Puerto Rico, and Venezuela, and 30% or more in Brazil and Chile.
These proportions appear to underestimate the actual toll of pedestrian deaths
because in most countries 30-50% of MVTA deaths were assigned to “unspecified” categories,
where the victim’s mode of transport was unknown or the type of vehicle
was unspecified. However, studies in Mexico and Colombia indicate that pedestrians
are the most vulnerable road users especially in main urban areas such as Mexico
City (54% of traffic deaths, 1994-1995), Bogotá, Medellin and Cali (32%
of injuries, 40% of traffic deaths overall and 68% of fatalities in Bogotá,
1996-2000).6,7 In contrast, motor vehicle occupant deaths accounted for 30-50%
of MVTA deaths in Argentina, Canada, Cuba, Puerto Rico and United States; 10-25%
in Brazil, Colombia, Mexico, and Venezuela and less than 10% in Chile during
1996-2001. The results highlight the relevance of the information on the characteristics
of the injured person, particularly whether he/she was an occupant of a vehicle
or a pedestrian, for the design of intervention strategies.
Figure 1: Trends of MVTA in Brazil, Guatemala, Chile, and Mexico, 1985-2001.
Figure 2: Trends of MVTA in Argentina, Colombia, Venezuela, and Puerto Rico,
1985-2001
Figure 3: Trends of MVTA in Belize, Canada, Cuba, and the United States, 1985-2001
The average crude mortality rate from MVTA observed during 1985-2001 ranged
from highs of 22.8 and 21.9 per 100,000 population in Brazil, and Venezuela
to lows of 4.8 and 10.0 per 100,000 population in Guatemala and Chile. Similarly,
the highest average rates were found among males in Brazil (36.0) and Venezuela
(34.6) and the lowest male rates in Guatemala (7.5), Argentina (15.8) and Chile
(16.3). Overall, average female crude rates were much lower than males. They
ranged from highs of 9.9 and 10.0 per 100,000 population in Brazil and the
United States to average lows of 2.0 and 3.9 per 100,000 population in Guatemala
and Chile, respectively.
While deaths rates are powerful indicators of the relative magnitude of the
problem, they do not measure the full burden of injuries due to motor vehicle
crashes. Indicators of morbidity, disability, and the economic cost of injuries,
among others, are necessary to provide a full picture of the situation.
Trends in MVTA
Over the period 1985-2001, age and sex standardized rates from motor vehicle
traffic accidents shown in Figures 1, 2, and 3 show a declining trend in
Mexico, Colombia, Brazil, Canada, United States, Cuba and Puerto Rico; and
an increasing trend in Belize and Chile and, from 1996, in Venezuela. The
rates were slightly decreasing in Guatemala and steady in Argentina. The
effect of the change in ICD revisions is probably reflected in noting that
in the year that countries changed to ICD-10 (Brazil, Venezuela 1996; Argentina,
Belize, Chile and Colombia 1997; Mexico, 1998; Puerto Rico and United States
1999; Canada 2000 and Cuba 2001), MVTA rates tended to drop and then increase
the following year. Belize was the exception when a dramatic two-fold rate
increase was observed, which may reflect, in part, changes in ICD and some
other unknown effect. Caution should be observed in the interpretation of
the rates in Chile which may be underestimated since on average, over the
period, one third of the deaths from all external causes have been assigned
to “events of unknown intent” (ICD-10: Y10-Y34, ICD-9:E980-E988)
and may include deaths involving motor vehicles. This proportion varies over
time and might also affect the actual trend. Average age standardized rates
from motor vehicle traffic accidents in this period showed that Venezuela
and Brazil had the highest rates, 24.1 and 24.2 per 100,000 population, respectively,
while the lowest average rates were found in Guatemala and Argentina, 6.1
and 9.7. Among males, the highest average age standardized rates again were
found in Brazil and Venezuela, 38.0 and 38.8 per 100,000 and lowest in Guatemala
and Argentina, 9.7 and 15.0, respectively. Among females, the United States
and Venezuela had the highest average age standardized rates, 9.5 and 9.6
respectively, and Argentina and Belize the lowest, 4.7 and 6.3, respectively.
Masculinity mortality ratios (the ratio of age standardized male: female
deaths per 100,000) with values over 1.0 indicating “excess” male
mortality, highlight the relative severity of this problem in males. These
ratios ranged from an average of 2.3 in Canada and United States to around
4.0 in Puerto Rico, Venezuela, Guatemala, and Chile, and to 5.4 in Belize
during 1985-2001. Excess male mortality increases the number of widows and
orphans and exposes them to a higher risk of economic difficulty.
As can be seen in Figures 4, 5 and 6, age specific
death rates show a similar toll of excess male to female deaths per 100,000,
in Brazil, Canada and Mexico, particularly after age 15. The age specific death
rates, especially in males, observed in Brazil, 2000 demonstrate a rapid increase
in MVTA mortality from 5-14 years of age to the most vulnerable age groups
15-24, 25-44 and 45-64 years of age. The trend is similar in Mexico 2001, but
with smaller increases observed in the age groups 25-44 and 45-64 years of
age. In contrast, age specific rates in Canada in 2000 increase from 1-4 to
a maximum at 15-24 years of age then decrease through 45-64 and then increase
in those aged 65 years and over. This is consistent with the finding that in
high income countries, adults aged between 15 and 29 have the highest rates
of injuries. 4 Contributing risk factors for this age group include unfamiliarity
with vehicles, thrill-seeking and over-confidence, less tolerance of alcohol
compared with older people, and excess or inappropriate speed.4 In Puerto Rico
(2000) and United States (2000), similar decreases in rates from ages 15-24
to 25-44 year were seen, while rate decreases were also seen in these age groups
for females in Belize (2000), Cuba (2001), Argentina (2001), and Venezuela
(2000) [data not shown]. Overall, elderly people are more likely to be killed
or seriously disabled than younger people due to their lack of resilience.4
These preliminary results suggest the need for a more detailed analysis on
the risk factors involved prior to suggesting interventions in a more specific
way.
Figure 4: Age-specific death rates from MVTA per 100,000 population, Brazil,
2000
Figure 5: Age-specific death rates from motor vehicle traffic accidents per
100,000 population, Canada, 2000
Figure 6: Age-specific death rates from motor vehicle traffic accidents per
100,000 population, Mexico, 2001
Injury prevention
To a large degree, MVTA are preventable and can be influenced through national
policy decisions, education and individual choices. As the number of cars
increases, the roads have become more dangerous and the expected number of
deaths and injuries will continue to rise relative to the number of vehicles
on the road. The most important risk factors for motor vehicle injury identified
are driving while impaired by alcohol or drugs and failing to use occupant
protection (e.g., safety belts, child safety seats, and motorcycle helmets),
speeding, poor road planning and road construction which does not plan for
the interaction of different road users, especially pedestrians, unsafe vehicle
design and inadequate implementation of road safety measures. Increasing
the standards for motor vehicle crash worthiness and proper road design can,
however, reduce their frequency and/or prevent crashes. It is nevertheless
important to note that risk factors vary from one setting to the other, and
that only high quality data on the nature of the crash and of the injured
persons will allow for adequate prevention strategies to be put in place.
Researchers over the years have generated evidence on the injury problem,
its risk factors, and ways to prevent motor vehicle fatalities long before
changes occurred in public policy and legislation. They have noted the increased
risk of motor vehicle accidents with drinking and driving and, the life-saving
effects of the use of seat belts and occupant restraints for infants and small
children. Unfortunately, data alone cannot always bring about changes in policies
that affect individual behavior. Further, prevention strategies need to be
customized to the specific situation of countries and not all measures work
in all settings. The data that is collected needs to be analyzed and demonstrate
the health, social and economic impact of road traffic injuries as well as
to monitor and evaluate road safety interventions. Public support for enforcement,
enactment of new laws, road safety education and implementation of mass transportation
systems and insurance programs to cover health care costs of victims has led
to reductions in motor vehicle fatalities yet the toll is still high. Successful
strategies in reducing injuries suggest a multi-sectorial approach involving
the sectors of health, transport, education, law enforcement and environment.
Governments have a critical role to play in prevention efforts and in creating,
fostering and maintaining an environment for road safety.
References:
(1) A 5-year WHO strategy for road traffic injury prevention. Department of
Injuries and Violence Prevention, World Health Organization. 2002.
(2) Global road safety crisis. Report of the Secretary-General. (A/RES/57/309).
United Nations, N.Y. 2003
(3) WHO. The Injury Chart Book. Geneva 2002
(4) World Health Organization. World Report on Road Traffic Injury Prevention.
WHO: Geneva. 2004
(5) Pan American Health Organization, Technical Information System, Area of
Health Analysis and Information Systems, 2004.
(6) Pedestrian traffic injuries in Mexico: A country update. Martha Hijar,
et.al. Injury Control and Safety Promotion 2003, Vol. 10, No. 1-2, pp. 37-43
(7) Road traffic injuries in Colombia. Deysi Yasmin Rodriquez, et. al., Injury
Control and Safety Promotion 2003, Vol. 10, No. 1-2, pp. 29-35
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Epidemiological
Bulletin , Vol. 25 No. 1, march 2004
