Abstract

INTRODUCTION

Traffic accidents remain a significant public health problem in Brazil and preventative activities require different approaches. The dynamic of this multi-causal phenomenon affects victims to different degrees depending on the type of accident (run over pedestrian, motorbike accident or another type of accident involving a vehicle or motorbike) ¹1 . Alves EF. Características dos acidentes de trânsito com vítimas de atropelamento no município de Maringá-Pr, 2005-2008. Saud Pesq . 2010;3(1):25-32. and demographic characteristics (sex, age, skin color, marital status and schooling). ¹²12 . Kmet L, Brasher P, Macarthur C. A small area study of motor vehicle crash fatalities in Alberta, Canada. Accid Anal Prev . 2003;35(2):177-82. DOI:10.1016/S0001-4575(01)00101-4 ^{, 20}20 . Soares DFPP, Barros MBA. Fatores associados ao risco de internação por acidentes de trânsito no Município de Maringá-PR. Rev Bras Epidemiol . 2006;9(2):193-205. DOI:10.1590/S1415-790X2006000200006 Monthly distribution is differentiated by day of the week and time of day. ⁵5 . Bastos YGL, Andrade SM, Soares DA. Características dos acidentes de trânsito e das vítimas atendidas em serviço pré-hospitalar em cidade do Sul do Brasil, 1997/2000. Cad Saude Publica . 2005;21(3):815-22. DOI:10.1590/S0102-311X2005000300015 Research using analysis techniques to understand these characteristics are relevant to redirecting activities aiming to reduce the severity of the accidents.

The factors involved, implicitly or explicitly, which can contribute to a greater or lesser extent to casuistry are: man; vehicle; road and environment; and factors referring to legislation and complying with it. ⁴4 . Barss P, Kahn JP, Mastroianni AC, Sugarman J. Injury prevention: an international perspective epidemiology, surveillance, and policy. New York: Oxford University Press; 1998. Separating these factors and studying their associations is necessary in order to better understand and intervene in the phenomenon of traffic accidents. This is because these factors combined may increase the likelihood of accidents in different ways in specific areas. ^aaRaia Jr AA, Santos L. Acidente zero: utopia ou realidade? 15º Congresso brasileiro de transporte e trânsito. 2005; Goiânia, BR, Goiânia: Centro de Convenções de Goiânia; 2005. p.7. ^{, b}bRaia Jr AA. Identificação de pontos críticos de acidentes de trânsito no Município de São Carlos, SP, Brasil: análise comparativa entre um banco de dados relacional – BDR e a técnica de Agrupamentos pontuais. Anais do 2º Congresso Luso Brasileiro para o Planejamento, Urbano, Regional, Integrado, Sustentável, 2006; Braga, PT, Braga: Universidade do Minho; 2006.

A significant number of studies in Brazil have looked at fatalities due to traffic accidents. However, there are few studies that deal with survivors of these accidents, which has led some authors to emphasize the importance of research into non-fatal accidents. ⁹9 . Deslandes SF, Silva C. Análise da morbidade hospitalar por acidentes de trânsito em hospitais públicos do Rio de Janeiro, RJ, Brasil. Rev Saude Publica . 2000;34(4):367-72. DOI:10.1590/S0034-89102000000400009 ^{, 10}10 . Gawryszewski VP, Koizumi MS, Mello-Jorge MHP. As causas externas no Brasil no ano 2000: comparando a mortalidade e a morbidade. Cad Saude Publica . 2004;20(4):995-1003. DOI:10.1590/S0102-311X2004000400014 ^{, 14}14 . Mello Jorge MHP, Gawryszewski VP, Latorre MI. Análise dos dados de mortalidade. Rev Saude Publica . 1997;31(4Suppl):5-25. DOI:10.1590/S0034-89101997000500002
https://doi.org/10.1590/S0034-8910199700... ^{, 18}18 . Ott EA, Favaretto ALF, Neto AFPR, Zechin JG, Bordin R. Traffic accidents: characterization accidents and lesions in an urban center of southern Brazil. Rev Saude Publica . 1993;27(5):350-6. DOI:10.1590/S0034-89101993000500005 ^{, c}cSoares DFPP. Acidentes de trânsito em Maringá-PR: Análise do perfil epidemiológico e dos fatores de risco de internação e de óbito. 2003 [tese de doutorado]. Campinas: Universidade Estadual de Campinas; 2003. In addition to being scarce, these studies make use of different methodologies different sources of data. A large part of this output refers to problems with the coverage and quality of the official information systems as limiting factors to understanding this phenomenon. ²⁰20 . Soares DFPP, Barros MBA. Fatores associados ao risco de internação por acidentes de trânsito no Município de Maringá-PR. Rev Bras Epidemiol . 2006;9(2):193-205. DOI:10.1590/S1415-790X2006000200006

For specialists, the lack of an integrated information system based on standardized police reports of traffic accidents makes it impossible to really know the situation of traffic accidents in the country and, therefore, makes it impossible to put in place appropriate measures to mitigate it. ⁷7 . Branco AG. A falta de estatísticas confiáveis dificulta a formatação de políticas públicas para solucionar os problemas no trânsito. Rev ABRAMET . 2003;11(21):33-47. As a way of overcoming this difficulty, techniques to relate databases were used in order to improve the quality of information on the number of variables investigated and the number of valid records, achieving more complete information.

This study aimed to describe characteristics of the victims, the roads and the vehicles involved in traffic accidents and risk factors for fatal accidents.

METHODS

A non-concurrent cohort study of traffic accidents that occurred within the geographical limits of Fortaleza, CE, Northeastern Brazil, between January 1 ^st 2004 and December 31 ^st 2008. The incidents covered those registered in Police Incident Reports (PI) recorded in the Fortaleza Traffic Accidents Information System (SIAT-FOR) and run by the Fortaleza Municipal Transit Authority (AMC). A traffic accident was deemed to be any incident that occurred on a public road, including not only crashes between vehicles but also collisions with fixed objects, collisions between pedestrians and cyclists, vehicles overturning, running over pedestrians and vehicles leaving the road. ¹⁷17 . Organização Mundial de Saúde. Classificação internacional de doenças e problemas relacionados à saúde. 10. ed. rev. São Paulo: Editora Edusp; Universidade de São Paulo; 2007. v.1. Criteria for inclusion were the accident being recorded in a PI, with or without injuries or fatalities among the victims and accidents that were not recorded in a PI were excluded.

Fortaleza is a metropolitan agglomeration in the Northeast of Brazil and is classed as the fifth largest city in the country. The urban area is crisscrossed by a 3,700 km network of roads. Of this total, around 35 km are under state jurisdiction and 25 km under federal jurisdiction. ^ddDepartamento Nacional de Trânsito (BR). Anuário estatístico de acidentes de trânsito de Fortaleza - 2008. Ceará; 2009. The road layout follows a radio-centric pattern and constituted the main connections between the urban area and neighboring municipalities. The roads are narrow as they originate in a layout defined when the city was founded and due to their use not being managed and a lack of control in occupation of the terrain, this makes it unviable to extend them and the system has become insufficient. ^eeMuniz MPC. O Plano Diretor Como Instrumento de Gestão da Cidade: o caso da cidade de Fortaleza/CE. Ceará: Universidade Federal do Rio Grande do Norte; 2006.

Data were collected from the SIAT-FOR system, which includes ten bodies involved in dealing with traffic accidents in the municipality.

Data from the Habilitação e Veículos do Departamento Estadual de Trânsito (DETRAN-CE – State Traffic Department Driving Licenses and Vehicle) database were also used, as were data from the Informações de Mortalidade (SIM – Mortality Information System), which contains death certificates and data from the Sistema de Informações Hospitalares (SIH – Hospital Information System), with the aim of obtaining complementing the data. Databases on hospitalization and deaths (SIH and SIM) were accessed through the Ceará State Department of Health (SESA). The data from the SIM refer to all deaths that occurred in Ceará between January 2004 and March 2009, as accidents occurring in December may have led to death in 2009. Data on hospitalization in the Brazilian Unified Health System (SUS) network in Fortaleza are for between January 2004 and July 2009, as requests for payment can be presented up to six months after being authorized.

Data on vehicles and driving licenses were obtained from DETRAN-CE and refer to all vehicles and licenses in the state of Ceará up to December 31 ^st , 2008.The variables investigated were categorized in four groups: characteristics of the victim, subdivided into socio-demographic characteristics, length of time driving and state of vehicle at the time of the accident; variables related to the time (year, time and week); jurisdiction of the road, location of the accident and illumination; type of accident, type and age of vehicle.

The databases were linked using relationship techniques to create one single database containing information on the vehicle, the road, the driver and the individuals involved.

Two methods were used in this process: deterministic and probabilistic relationship techniques. ⁶6 . Blakely T, Salmond C. Probabilistic record linkage and a method to calculate the positive predictive value. Int J Epidemiol . 2002;31(6):1246-52. ^{, 13}13 . Machado CJ, Hill K. Probabilistic record linkage and an automated procedure to minimize the undecided-matched pair problem. Cad Saude Publica 2004;20(4):915-25. DOI:10.1590/S0102-311X2004000400005

Data on the accidents collected by the SIAT-FOR system were complemented according to the two types of relationship, involving two different stages. In the first, deterministic, stage the SIAT-FOR database, provided by the AMC, regarding vehicles which had been involved in traffic accidents, was linked to the DETRAN-CE database using vehicle license plates to obtain information on the year and type of vehicle. Data on the driver: type and year of driving license, sex, marital status, level of schooling, date of birth and mother’s name were obtained from the database provided by DETRAN-CE based on the driving license number, registered in the SIAT-FOR system database of individuals involved in traffic accidents.

Complementing the data concerning pedestrians and passengers involved in traffic accidents was achieved by using probabilistic relationship technique, together with the SIM and SIH systems. The key variables were: name and age of victim and date of the accident when the individual died or was hospitalized in the SUS network.

In order to analyze the traffic accidents, a set of co-variables was created based on the variables described: type and number of vehicles involved, type and number of individuals, age of the vehicles, sex of the driver, status of the drivers’ licenses, length of time drivers had been driving and their age, marital status and schooling.

Descriptive data were presented according to the variables in question. Pearson’s Chi-squared test, Fisher’s exact test and the Student t-test were used in the comparative analysis. Estimated risk of a fatal accident was verified with bivariate analysis using the odds ratio, with a 95% confidence interval. Variables which had an association with a fatal accident of p < 0.20 according to the Chi-squared test were selected to be included in the multinomial analysis. ¹¹11 . Hosmer DW, Lemeshow S. Applied logistic regression. 2 ed. New York: Wiley-Interscience; 2000.

The multinomial analysis was carried out using the Generalized Linear Model (GLM) with binomial distribution and the logistic link function. The choice of this distribution was justified as the measurement of the outcome was dichotomous.

The modelling followed the strategy recommended by Hosmer & Lemeshow ¹¹11 . Hosmer DW, Lemeshow S. Applied logistic regression. 2 ed. New York: Wiley-Interscience; 2000. and each variable was withdrawn after comparison of the models’ likelihood ratio (-2logL) with and without the variable in question. Variables remained in the model according to theoretical justifications and statistical significance.

The final model was assessed for sensitivity, specificity accuracy and based on the percentage improvement of the model in relation to the initial deviance (likelihood ratio). The value of the area above the ROC curve was 0.86, indicating high discriminatory power.

The research was approved by the Ethics Committee of the Universidade Federal do Ceará (Process No. 90/2008).

RESULTS

There were 118,830 traffic accidents in Fortaleza between January 2004 and December 2008, 1.4% were fatal and 46.6% involved serious or minor injuries. Of the incidents, 78.1% were categorized as a cash/collision and 11.9% were pedestrians run down, 3.9% were collisions with a fixed obstacle, 0.5% involved the vehicle overturning and 5.6% involved the vehicle falling/leaving the road and other types of accidents on public roads (Table 1).

The annual mean number of accidents in the period was 23,767 accidents/year, and the highest number of incidents was recorded in 2008 (20.8%; p < 0.001). The monthly mean for the period was 1,981 accidents/month. The quarter from October to December stands out as having the highest number of accidents (mean of 6,382 accidents), while the January to March quarter had the lowest number of accidents (mean of 5,421 accidents; p < 0.001) (Table 1).

Around 43.7% of the accidents occurred between cars and/or trucks, 26.5% involved motorcyclists and 8.5% were between motorcyclists. Accidents involving more than two vehicles were in the minority throughout the study, especially in 2005 (4.7%; p < 0.001) (Table 1).

In 75.1% of the accidents, only one driver of a motorized vehicle was involved. Accidents involving passengers in any type of vehicle were in the minority throughout the period (5.2%). The mean number of individuals involved in accidents was 2.03 individuals/accident.

Almost two thirds (65.1%) of incidents occurred in moving traffic, categorized as mid-block, followed by at intersections (30.0%); 67.6% occurred in daylight, 13.1% during the night on illuminated roads and 11.6% at dusk. Unlit or poorly lit streets accounted for 3.7% and 4.0% occurred at dawn; 63.2% of accidents occurred during the day. The afternoon, between 12.00 and 18.00, was the period in which the highest number of incidents were recorded (35.1%) ( Table 1 ).

Almost all incidents (92.6%) occurred under municipal jurisdiction, followed by state jurisdiction (4.5%), due to the distribution of jurisdiction in the city’s road network. Saturday was the day on which most accident occurred (17.3%), followed by Friday (15.9%) and Sunday (14.5%). Tuesdays and Wednesdays are the days on which fewest accidents occurred (12.7% and 12.9%, respectively) ( Table 1 ).

In the bivariate analysis, accidents involving bicycles had the highest gross risk (OR = 3.95; 95%CI 3.44;5.17) of being fatal, based on accidents with automobiles or trucks. Accidents between motorcycles had the second highest gross risk of being fatal (OR = 2.88; 95%CI 2.48;3.34). Accidents involving one vehicle had a higher risk of fatalities (OR = 4.15; 95%CI 3.77;4.57) than accidents with two vehicles ( Table 2 ).

Running over pedestrians (OR = 6.32; 95%CI 5.71;6.98) had a higher gross risk of being fatal, followed by accidents involving the vehicle overturning (OR = 4.90; 95%CI 3.32;7.24) and colliding with a fixed obstacle (OR = 3.57; 95%CI 2.98;4.28), compared with crashes or collisions ( Table 2 ).

Individuals holding a license for fewer than five years (OR = 1.78; 95%CI 1.52;2.08) had a higher gross risk of being involved in a fatal accident compared with drivers with more than five years’ experience. Drivers without an appropriate license (OR = 1.95; 95%CI 1.74;2.18) had the highest risk of being involved in a fatal accident, compared with licensed drivers ( Table 3 ).

Accidents in moving traffic or mid-block (OR = 2.02; 95%CI 1.79;2.19) had the highest gross risk of involving fatalities and occurred with higher frequency, in contrast to accidents at level crossings (OR = 8.50; 95%CI 5.44;13.30), which carry a higher risk of fatality but occur with less frequency. Around 18.9% of incidents occurred at traffic lights and do not carry a risk of fatalities compared with overhead road signs. Accidents involving lateral road signs (OR = 2.26; 95%CI 1.92;2.66) represented 63% of the total and had a gross risk of fatal accidents compared with overhead road signs ( Table 1 , Table 2 ).

The severity of the accidents proved to be more accentuated at a federal level federal (OR = 4.30; 95%CI 3.70;4.99), followed by a state level, compared with municipal. The gross risk of fatal accidents was higher at dusk (OR = 2.78; 95%CI 2.32;3.34) compared with daylight. Sunday (OR = 2.11; 95%CI 1.76;2.53) was the day with the highest gross risk of fatal accidents compared with Wednesday. The gross risk of a fatal accident was higher in the early hours of the morning (OR = 2.42; 95%CI 2.07;2.82), followed by during the night (OR = 1.48; 95%CI 1.30;1.68) compared with in the morning ( Table 2 ).

In the multinomial analysis, the presence of drivers who do not have a license (OR = 4.1; 95%CI 2.9;5.5) or do not have a license appropriate for the vehicle (OR = 1.6; 95%CI 1.2;1.9), using roads that are under federal jurisdiction (OR = 2.4; 95%CI 1.8;3.1), early hours of the morning (OR = 2.4; 95%CI 1.8;3.0) and Sundays (OR = 1.7; 95%CI 1.3;2.2) all stand out as contributing factors to fatal accidents ( Table 3 ).

Accidents involving motorcyclists (OR = 3.5; 95%CI 2.6;4.5) were potentially fatal. The traffic accidents with the highest risk of fatality were those involving bicycles (OR = 21.2; 95%CI 16.1;27.8), running over pedestrians OR = 5.9 (95%CI 3.7;9.2) and collisions with fixed obstacles OR = 5.7 (95%CI 3.1;10.4).

DISCUSSION

Brazil is moving onto the world stage due to its promising economic growth, however, morbidity and mortality due to traffic accidents is recognized as a large-scale and highly complex phenomenon. It represents the relationship between investments in road safety, economic development policies centered around the automotive industry and traffic education.

Analyzing the factors which affect the occurrence of traffic accidents is a complex procedure as they are numerous and they are not independent. ⁸8 . Crundall D, Clarke D, Ward P, Bartle C. Road safety good practice guide. London: Defence Terrain Research Laboratory; 2001. The results of this study provide a broader view of the phenomenon of traffic accidents based on its analysis of characteristics of the road, the individuals and the vehicles involved. This aspect highlights the importance of inter-sector practices to better deal with the problem, in view of its complexity and the multiplicity of factors related to diverse areas of human knowledge.

Road structure, signs and illumination, the day of the week and time of day of the occurrence are connected to the severity of traffic accidents. Researchers have found similar results and attribute higher fatality rates to weekends and the early hours, to drinking and driving and speeding. ²2 . Abreu AMM, Lima JMB, Griep RH. Acidentes de trânsito e a frequência dos exames de alcoolemia com vítimas fatais na cidade do Rio de Janeiro. Esc Anna Nery Rev Enferm . 2009;13(1):44-50. DOI:10.1590/S1414-81452009000100007 On the other hand, it is important to bear in mind the role of poor quality of lighting and adequate signage as a parameter of safety. ¹⁶16 . Montenegro MMS, Duarte E, Ruscitto RP, Nascimento AF. Mortalidade de motociclistas em acidentes de transporte no Distrito Federal, 1996 a 2007. Rev Saude Publica . 2011;45(3):529-38. DOI:10.1590/S0034-89102011000300011
https://doi.org/10.1590/S0034-8910201100...

Severity of the accident is related to the type of jurisdiction of the road, with higher risks at a federal level, followed by state, compared to municipal. The speed limit on each type of road and the flow of traffic differs and lead to congestion on municipal roads, leading to less serious accidents without injuries.

Drivers who have held a license for fewer than five years have the highest risk of being involved in a fatal accident, in contrast with the findings of other studies, which highlight older motorists as significantly more likely to be involved in serious and fatal accidents, when figures are adjusted for differences in exposure. ²²22 . Young-Jun Kweon, Kara M. Kockelman, Overall injury risk to different drivers: combining exposure, frequency, and severity models. Accident Analysis & Prevention, Volume 35, Issue 4, July 2003, Pages 441-450, ISSN 0001-4575. DOI:10.1016/S0001-4575(02)00021-0.
https://doi.org/10.1016/S0001-4575(02)00... This information places the Brazilian process of issuing driving licenses under discussion. Lack of experience on the part of new drivers is an implicit criticism of the rigidity of the traffic code which stipulates that a learner’s permit for up to a year is not sufficient to make them fit to drive vehicles.

Traffic, the condition of the road and the greater flow of individuals commuting increase exposure to the problem. Added to this is the culture of punishment at the expense of education around this phenomenon. These obstacles impede an improvement in the indicators, despite the implementation of public policies which attempt to mitigate the phenomenon. The more vulnerable population groups (pedestrians, cyclists and motorcyclists) become victims of the conditions of the road, the vehicles and the road users.

There are differences in the seriousness of traffic accidents according to type. Running over pedestrians and accidents involving cyclists and motorcyclists are described as more serious. ¹1 . Alves EF. Características dos acidentes de trânsito com vítimas de atropelamento no município de Maringá-Pr, 2005-2008. Saud Pesq . 2010;3(1):25-32. This fact is explained by the kinematics of trauma, and will continue to be a problem until equality exists in traffic.

The individual’s position in the traffic is a determinant of the seriousness of the injury. The risk of death is higher among cyclists and pedestrians. This fact has also been presented in other studies, in which pedestrians and cyclists are the most vulnerable road users and make up the highest percentage of victims. ¹⁹19 . Silva DW, Andrade SM, Soares DA, Paula Soares DFP, Mathias TAF. Perfil do trabalho e acidentes de trânsito entre motociclistas de entregas em dois municípios de médio porte do Estado do Paraná, Brasil. Cad Saude Publica . 2008;24(11):2643-52. DOI:10.1590/S0102-311X2008001100019 Whereas cyclists lack proper cycle lanes and need to struggle with the vehicles for space amid the oppression and the fumes, pedestrians are faced with narrow poorly maintained sidewalks. This occurs despite Fortaleza being a flat city where these methods of transport should, for diverse reasons, be prioritized: health, environment and economy.

Congestion in the large cities, inefficient public transport, tele-deliveries and mototaxis have led to the rapid spread of motorcycle use, representing an increase of 700% in fatalities between 1998 and 2008. ³3 . Bacchieri G, Barros AJD. Acidentes de trânsito no Brasil de 1998 a 2010: muitas mudanças e poucos resultados. Rev Saude Publica . 2011;45(5):949-63. DOI:10.1590/S0034-89102011005000069 Their low cost and facilitated financing are responsible for the significant increase in motorcycles. The problem of the severity of this type of accident, as evidenced in this and other studies, raises the need to think about the safety of these road users.

Accidents in which only one vehicle was involved had a higher risk of fatality compared with accidents with two vehicles. Conflicts in traffic with more susceptible vehicles such as motorbikes and bicycles can lead to the driver falling. According to the kinematics of trauma, the injury is more severe where there is a greater transference of kinetic energy. This was proved in this study, in which the main type of accidents involving fatalities were those involving collisions with fixed objects and running down pedestrians. Speed is the most significant producer of this energy.

Both severity and incidence of accidents increase during the night and at the weekends, due to lack of congestion and drinking and driving, in view of the devastating effect of combining drink driving and speeding.

A difference was observed in the distribution of occurrence according to month, day of the week and time. ⁵5 . Bastos YGL, Andrade SM, Soares DA. Características dos acidentes de trânsito e das vítimas atendidas em serviço pré-hospitalar em cidade do Sul do Brasil, 1997/2000. Cad Saude Publica . 2005;21(3):815-22. DOI:10.1590/S0102-311X2005000300015 Socio-demographic factors such as sex, age and schooling are related to the occurrence and the severity of accidents. ¹²12 . Kmet L, Brasher P, Macarthur C. A small area study of motor vehicle crash fatalities in Alberta, Canada. Accid Anal Prev . 2003;35(2):177-82. DOI:10.1016/S0001-4575(01)00101-4 ^{, 20}20 . Soares DFPP, Barros MBA. Fatores associados ao risco de internação por acidentes de trânsito no Município de Maringá-PR. Rev Bras Epidemiol . 2006;9(2):193-205. DOI:10.1590/S1415-790X2006000200006

Individuals who are single are at greater risk than married individuals of suffering a serious or fatal traffic accident, even after adjusting for sex, age and alcohol, ²¹21 . Whitlock G, Norton R, Clark T, Jackson R, MacMahon S. Motor vehicle driver injury and marital status: a cohort study with prospective and retrospective driver injuries. Inj Prev . 2004;10(1):33. DOI:10.1136/ip.2003.003020 which may be due to the fact that singles expose themselves more to risk factors, as confirmed in this study. The times and roads on which fatal accidents occur suggest less congested driving conditions and travelling connected to leisure activities, characterized by imprudence. This indicates the need for investment in preventing accidents and promoting safe driving through educational strategies, creating a culture of peace in the traffic.

Activities promoting the prevention of traffic accidents should prioritize and focus on accidents involving two wheeled vehicles, which often involve only one victim, on unqualified drivers, males, night time, weekends and on roads where higher speeds are reached.

It is possible to unify various sources of data from different sectors in order to improve understanding of traffic accidents so as to produce inter-sector public policies which aim to reduce deaths from this problem. This study’s analysis of the characteristics of risk in the accident, considering the individuals and the roads where the vehicles drive was an important contribution for increasing the number of factors related to this phenomenon.

A possible limitation of this study was using secondary data. However, we believe that the techniques used to link the databases are an innovation in dealing with factors which affect the severity of traffic accidents. The effort in integrating the different databases used and the results achieved go some way to substituting the need for establishing a unified information system which includes the variables necessary for analyzing the traffic situation in Brazil.

References

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History