Magdalena Lopez-Charneco,1M.S.; Maria S. Conte-Miller,2M.D.; Francisco Davila-Toro,2M.D.;
Enid J. Garc?a-Rivera,1,3M.P.H., M.D.; Diego E. Zavala,4Ph.D.; Yisel Torres,1M.P.H.; and
Jose F. Rodriguez Orengo,5Ph.D.
Motor Vehicle Accident Fatalities Trends,
Puerto Rico 2000–2007
Puerto Rico Institute of Forensic Science database, this study accessed the mortality trends of MVAF in Puerto Rico from 2000 to 2007. Descriptive
statistics, age-adjusted mortality rates, geographical analysis, and annual percentage change were calculated. An annual mean of 559 MVAF occurred
during the study period. The overall MVAF mortality rate declined from 2000 to 2007 (16.6 and 12.4 per 100,000 population, respectively)—mortal-
ity rates annually decreased 3%. Most MVAF (80.2%) occurred in men, showing a risk four times higher than women (23.6 and 5.4 deaths per
100,000 populations, respectively). Drivers aged 20–24 years and pedestrians older than 75 years had the highest risk of death. This study emphasizes
the need of public health efforts to focus on the prevention of MVAF in the most affected groups.
Motor vehicle accident fatalities (MVAF) are an important cause of death that affects millions of people worldwide. Using the
KEYWORDS: forensic science, epidemiology, mortality trends, road traffic, fatal injury, Puerto Rico, Hispanic
Motor vehicle accident fatalities (MVAF) have been character-
ized worldwide as a hidden epidemic, which affects all sectors of
the society (1,2). In 2000, the worldwide road traffic mortality rate
was 20.8 deaths per 100,000 population (30.8 in men, 11.0 in
women) (3). Over 50% of these deaths occurred among young
adults in the age range of 15–44 years. In children and young
people between 5 and 29 years, road traffic injuries are the second
leading cause of death worldwide (4). More than 41,000 people in
the U.S. die in motor vehicle crashes each year and crash injuries
result in about 500,000 hospitalizations and four million emergency
department visits annually (5). The economic burden of motor
vehicle–related deaths and injuries is enormous, costing the U.S.
more than $150 billion each year. For adults older than age 70, the
motor vehicle death rate has remained stable, at about 23 per
100,000 for more than a decade (6). MVAF remain the leading
cause of injury death in the U.S. (7) with a mortality rate of 14.7
per 100,000 in 2004.
In Latin America from 1997 to 2000, mortality from all land
transport accidents was the 10th leading cause of death in the
general population, the sixth leading cause in men, and the 16th in
women (8). Studies in Mexico and Colombia indicate that
pedestrians are the most vulnerable road users especially in main
The island of Puerto Rico is a U.S. Commonwealth located in the
Caribbean with an area of 3454 square miles (9104 km2). In year
2008, the estimated population by the U.S. Census Bureau was
3,954,037 with about 1155 people per square mile, a ratio higher
than most U.S. states (9). Private motor vehicles are the main source
of transportation making the traffic situation in this highly populated
island very complex. During the year 2007, there were 3,031,124
motor vehicles registered by the Puerto Rico Department of Trans-
portation and Public Works, representing almost one vehicle per
island resident (10). In 2007, the Puerto Rico Police Department
reported 266,767 automobile ‘‘accidents,’’ and the Puerto Rico
Administration for Compensation for Automobile Accidents referred
for treatment 39,888 injured persons during motor vehicle–related
accidents (M. Lopez-Charneco and E.J. Garc?a-Rivera, personal
communication). The congested highway system as suggested by
the annual average daily traffic (rural and urban: 5022 vehicles per
lane per day) makes Puerto Rico one of the 10th highest transited
jurisdictions in the U.S., a fact of life for urban dwellers (11).
This article presents an analysis of mortality trends attributed to
MVAF in Puerto Rico between the years 2000 and 2007. The eval-
uation of mortality rates by nature of injury during this period can
aid in developing evidence-based prevention strategies (12).
We used data obtained from all motor vehicle–related deaths
investigated by the Puerto Rico Institute of Forensic Sciences
(PRIFS) from 2000 to 2007. The PRIFS was created in 1985 to
investigate, using scientific methods, all forensic evidence to
1Puerto Rico Department of Health, Office of Epidemiology and
Research, PO Box 70184, San Juan 00936, Puerto Rico.
2Puerto Rico Institute of Forensic Sciences, Calle Maga Esq. Casia Urb.
Reparto Metropolitano, San Juan 00936, Puerto Rico.
3Department of Medicine, University of Puerto Rico School of Medicine,
PO Box 365067, San Juan 00936-5067, Puerto Rico.
4Ponce School of Medicine, PO Box 7004, Ponce 00732-7004, Puerto
5Department of Biochemistry, University of Puerto Rico School of Medi-
cine, PO Box 365067, San Juan 00936-5067, Puerto Rico.
Received 2 Feb. 2010; and in revised form 25 May 2010; accepted 12
J Forensic Sci, September 2011, Vol. 56, No. 5
Available online at: onlinelibrary.wiley.com
2011 American Academy of Forensic Sciences
Published 2011. This article is a U.S. Government work and is in the public domain in the U.S.A.
understand the cause, manner, and circumstances of violent deaths
in Puerto Rico. This agency receives all MVAF from Puerto Rico
for investigation. During the study period 19,023 deaths were
investigated. Of these, 23% were caused by MVAF. In this study,
we included all closed cases from January 1, 2000 to December
31, 2007. Deaths under investigation after October 21, 2008 were
excluded from the analysis (represents <1% of all external cause of
Case Definitions and Classifications
Road traffic injury was defined as an unintentional vehicle injury
occurring on a public road or highway including vehicle injuries
where the place of occurrence was unspecified. MVAF were
defined as an unintentional vehicle injury occurring on a public
road or highway resulting in death.
We classified the victims as driver, passenger, pedestrian, motor-
cyclist, cyclist, and others (e.g., horseman and pilot). Gender was
operationally defined as men or women. The age variable was
classified in the following age groups according to the Center for
Disease Control (CDC) recommendations at ‘‘The State Injury
Indicators: Instructions for Preparing 2005 Data’’ (13): <5, 5–14,
15–19, 20–24, 25–34, 35–44, 45–54, 55–64, 55–64, 65–74,
75–84 years, and 85 or older. Month variable indicates when the
incidents occurred and municipality indicates the place where the
A descriptive analysis in time, place, and person was performed.
Variables analyzed included gender and age group distribution, vic-
tim classification, year, month, and municipality of occurrence.
Crude and age-adjusted mortality rates were calculated. Census pop-
ulations’ estimates were used as denominators in crude mortality
rates calculations (Population Division, U.S. Census Bureau, 2008,
Rates were age-adjusted to the Puerto Rico standard 2000 Census
population. Join point regression analysis was performed to deter-
mine the significance of trends (14). Join point regression consists
of a series of permutations tests to define points in time were signif-
icant changes in trends occur. Join point presents the estimated
annual percentage change (APC) for each period identified, along-
side its 95% confidence intervals and is used as a way to compare
the significance of changes in periods of time. The APC was
calculated for overall MVAF and for the four most common victims
(driver, pedestrian, passenger, and motorcyclist). The MVAF age-
adjusted mortality rates by municipality were calculated and the
quartiles were employed as cut-off points. Municipalities with <20
cases, during the study period, were excluded from the analysis. Epi
Info 2000 (15) was used as statistical software and Epi Map was
used for the geographical analysis.
From January 1, 2000 to December 31, 2007, 4474 deaths attrib-
uted to MVAF were reported by the PRIFS. The annual mean of
MVAF-related deaths during the study period was 559 deaths per
year. Table 1 summarizes the MVAF characteristics. The overall
MVAF annual mortality rate decreased from 16.6 in 2000 to 12.4
deaths per 100,000 population in 2007 (Fig. 1) with a mean annual
mortality rate of 14.4 deaths per 100,000 population. Annual
MVAF rates decreased by 3.1% (APC, statistically different from
zero) during the study period.
Most MVAF occurred in men (80.2%). The rate of MVAF for
men was 4.4 times the rate for women (23.6 vs. 5.4 per 100,000
population, respectively). For women, there was a significant reduc-
tion in the MVAF rates (APC: )5.6%, statistically different from
zero), whereas for men, the reduction was not significant (APC:
)2.5%, nondifferent from zero) (Fig. 1).
When stratified by age group, higher rates of MVAF were iden-
tified among people aged 20–24 and those older than 75 years
(28.0 and 22.3 per 100,000 population, respectively) (Table 1).
TABLE 1—Characteristics of motor vehicle accident fatalities in Puerto
*Cumulative cases from 2000 to 2007.
?Mean of mortality rates per 100,000 population.
?The annual percentage change (APC) is the change in the mortality rate
per year from 2000 to 2007.
§Statistically different from zero.
FIG. 1—Age-adjusted mortality rate attributed to motor vehicle accident
fatalities by gender, Puerto Rico, 2000–2007.
LOPEZ-CHARNECO ET AL. • MOTOR VEHICLE ACCIDENT FATALITIES TRENDS
There was a significant decrease in the MVAF rates for the follow-
ing age groups: 5–14, 45–54, and 65–74 years (APC: )15.8, )5.2,
and )6.2, respectively, and statistically different from zero). Other
age groups had not significant APC in the MVAF rates.
Among women, the highest MVAF rate occurred in those
between 75 and 84 years (10.7 per 100,000 population). These
deaths occurred mostly among pedestrians (11.2%). On the other
hand, for men, the MVAF rate was highest among men aged 20–
24 years and older than 75 years (47.6 and 38.2 per 100,000 popu-
lation, respectively) (Fig. 2). Deaths on younger men and adults—
20 to 24 years—occurred in drivers (51.0%), motorcyclist (21.0%),
and passengers (17.2%). Most fatalities (67.7%) occurring in men
older than 75 years were pedestrians.
During the study period, of all MVAF victims 1591 (35.6%)
were drivers; followed by pedestrians (1475, 33.0%), passengers
(768, 17.2%), motorcyclists (528, 11.8%), and cyclists (90, 2.0%)
(Table 1). Gender-specific analysis showed that for men, the most
common MVAF occurred in drivers (38.2%) followed by pedes-
trian (32.8%) and motorcyclists (14.1%), while a higher percent of
women died as pedestrian (38.2%) and passengers (33.7%).
In the analysis of MVAF trends by type of victim, we found that
the drivers, passengers, and pedestrians mortality rates have been
significantly declining over time (APC: )3.9, )3.6, and )10.3,
respectively, and statistically different from zero). On the other
hand, the only group showing an increasing trend was the
motorcyclists (APC: 12.3, statistically different from zero) (Fig. 3).
The age group distribution was different by the victim classifica-
tion. The mortality rates for drivers, passengers, and motorcyclists
were higher in people aged 15–34 years. Conversely, the mortality
rates for pedestrians increased proportionally with age (Fig. 3).
There was no seasonality pattern for MVAF identified by month
of occurrence, and the rates of MVAF by month show little varia-
tion throughout the years under study (range: 7.5–9.7% monthly).
Figure 4 shows the geographical distribution of MVAF in Puerto
Rico. The municipalities with developed road infrastructure or
through which main highways have been built have the higher
MVAF rates. The highest mortality rates occurred in the municipal-
ities of San Juan, Salinas, and Manat? (23.9, 22.5, and 22.0 per
This study evaluates the trends in MVAF in the Puerto Rico
population from 2000 to 2007. We found that, even when MVAF
is still an important cause of death in Puerto Rico, the mean
MVAF rate during our study period showed a significant decrease
and was less than the worldwide annual estimates (20.8 per
100,000 population) for MVAF (3). Several factors might be
related with this finding. Puerto Rico has established aggressive
measures for the enforcement of seat belt regulations and has
implemented severe alcohol restrictions for drivers. These two
factors: failure to use seat belts and alcohol abuse; have been iden-
tified by experts on traffic safety as the most important risk factors
for traffic injuries. The implementation of measures to enforce seat
belt use in Puerto Rico have been proven to be successful. Accord-
ing to the National Highway Traffic Safety Administration, in
2008, seat belt use in the U.S. from a probability-based observa-
tional survey conducted by 50 states, the District of Columbia, and
U.S. Territories ranged from 55.7% in American Samoa to 97.2%
in Michigan. In that survey, Puerto Rico was one of the 16 jurisdic-
tions that achieved seat belt use rates of 90% or higher (16).
Alcohol consumption is another important factor associated with
MVAF. In this study, we did not evaluated the relationship
between alcohol consumption and MVAF. However, according to
the Fatality Analysis Reporting System, during the year 2007,
41.7% of the road fatal victims in Puerto Rico were associated with
the alcohol consumption (17). However, how this behavior might
be related with our findings is beyond the scope of this study. Un-
fortunetly, data on blood alcohol concentration was not available at
the time of the analysis. Structural deficiencies in road design and
traffic signals are also considered key factors (4,8).
In the Americas, Puerto Rico is categorized as a country with
medium risk (mortality rate from 10 to 20 deaths per 100,000
population) for MVAF mortality (17). The mean annual mortality
rate (14.2 per 100,000 population) in Puerto Rico compared with
the annual age-adjusted motor vehicle–related death rates in the
U.S. (range: 15.2–15.7 per 100,000 population) has remained
relatively unchanged since 1999. However, among states, substan-
tial differences are observed with average annual death rate ranging
from 7.9 per 100,000 populations in Massachusetts to 31.9 per
100,000 population in Mississippi (18). In comparison with states
and other U.S. jurisdictions, in 2006, Puerto Rico ranked within the
15 jurisdictions with lower mortality rates owing to MVAF (19).
Worldwide, gender-specific differences in road traffic mortality
rates have been described (4). Men have higher rates than women
in all regions, regardless of income level, and also across all age
groups (4,8,20–23). In Puerto Rico, a similar pattern also occurs.
The distribution of road traffic mortality rates in Puerto Rico was
FIG. 2—Mortality rates attributed to motor vehicle accident fatalities by
age group and victim classification, Puerto Rico, 2000–2007.
FIG. 3—Age-adjusted mortality rate attributed to motor vehicle accident
fatalities by victim classification, Puerto Rico, 2000–2007.
JOURNAL OF FORENSIC SCIENCES
4.4 times higher in men than in women. However, the gender-spe-
cific rates were lower for both men (23.9 deaths per 100,000 popu-
lation) and women (5.5 deaths per 100,000 population) to the rates
observed in others regions of the world (30.8 in men, 11.0 in
women per 100,000) (8).
Age group–specific mortality rates also showed a trend similar
to what has been found in other countries, in which the productive
(working) age groups (15–44 years) are most commonly affected
(4,19–22,24–26). The mortality rate in both, men and women,
increase for persons older than 75 years, particularly for the pedes-
trians. This finding emphasizes the need to develop public health
interventions to reduce road traffic injury-related mortality in this
We also found differences in MVAF using the victim classifica-
tion. In Puerto Rico, drivers are at greater risk of death, followed
by pedestrian and passengers. This is not consistent with reports
from other countries that have generally found pedestrians and two-
wheeler users at greater risk than vehicle occupants (4,8). This is
especially true in low-income and middle-income countries,
because of the greater variety and intensity of traffic mix and the
lack of separation from other road users (4). Cultural behaviors,
road infrastructure, and traffic regulations in Puerto Rico might be
related with this difference. Motorcyclists are of special interest,
because they were the only group in which MVAF showed an
increasing trend. The use of motorcycles is still not common in
Puerto Rico. Even when the number of registered motorcycles
increased from 33,000 in 1997 to 115,000 in 2007, they still repre-
sent only 4.3% of all registered vehicles (10). Aggressive enforce-
ment of helmet use and education of motorcyclist might be needed
to reduce that increasing trend. Likewise, the use of bicycles in
Puerto Rico is mostly for leisure activities, rather than as a means
of transport as in many low-income countries. In addition, there is
no great urban traffic mixture in Puerto Rico as that seen in the
large urban developments in low-income countries where pedestri-
ans, bicycles, and two- and four-wheeled vehicles interact greatly.
Thus, the majority of MVAF in Puerto Rico occurs in occupants of
motor vehicles (52.8%) and pedestrians (33.0%).
In contrast to the popular belief that most MVAF occurs dur-
ing the winter, we did not find any seasonal variation in MVAF
by month of occurrence. Given that the island is in the tropic,
the lack of winter weather has had no effect on the MVAF. On
other hand, we did find geographical differences in MVAF dis-
tribution. Urban and rural municipalities with highway infrastruc-
ture showed the highest MVAF rates. This also has important
implications for MVAF prevention. In the U.S., MVAF rates
were similar for the large central metro and large fringe metro
counties and these rates increase as a county becomes progres-
sively more rural (27).
While death rates are powerful indicators of the relative magni-
tude of the problem, they do not measure the full burden of the
injuries because of road traffic injuries. Indicators of morbidity,
disability, and economic cost of injuries among others are neces-
sary to provide a full picture of the situation. MVAF are prevent-
able and can be influenced through national policy decisions,
education, and individual choices. Puerto Rico has already taken
affirmative and successful actions to reduce the burden of road
traffic injuries. However, there are still groups disproportionately
affected by MVAF and public health interventions directed toward
these groups are needed.
From 2000 to 2007, the overall mortality rates caused by MVAF
declined. Young adults (20–24 years) had a higher risk of MVAF.
The study revealed that drivers, passengers, and pedestrian mortal-
ity rates show declining trends. Public health efforts should focus
on reducing MVAF in younger adult men to have an impact on
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Additional information and reprint requests:
Jose F. Rodriguez Orengo, Ph.D.
Department of Biochemistry
University of Puerto Rico School of Medicine
PO Box 365067
San Juan 00936-5067, Puerto Rico
JOURNAL OF FORENSIC SCIENCES