Do physical activity and trip characteristics differ when commuting to and from school?: The PACO study

Purpose: To determine whether trip characteristics (i.e., length, duration, and speed) and physical activity (PA) (i. e., light PA [LPA], moderate-to-vigorous PA [MVPA], and PA energy expenditure [PAEE]) differ by trip direction (i.e., home-school and school-home trips), and to examine differences in trips characteristics and PA levels between modes of commuting (walking, multimodal, and motorized-vehicle). Methods: 181 adolescents wore a belt on their hip with an accelerometer and a GPS. The HABITUS and PALMSplusR softwares were used to combine accelerometer and GPS data and identify trip characteristics and PA levels during home-school and school-home trips. Mixed model analysis was used to examine the differences in trip characteristics and PA levels between the trip directions and across modes of commuting. Results: The percentage of school-home walking trips was higher (54.4% vs 46.9%) and had longer duration than the home-school walking trips (p < 0.01). In contrast, multimodal and vehicle trips had a longer duration during the home-school direction than the school-home direction (p < 0.01). Regarding PA levels, the school-home direction presented higher LPA during walking trips (p < 0.01), but lower MVPA (p < 0.01), compared to the home-school direction. Walking trips presented higher MVPA and PAEE than multimodal and motorized-vehicle in both directions, but smaller LPA minutes in home-school direction than multimodal and motorized-vehicle (p < 0.01). Conclusion: The percentage of walking trips, the characteristics of the trips, and PA levels during school-home direction differed from home-school direction. In addition, walking trips were associated with higher MVPA levels and PAEE in both directions compare to multimodal or motorized-vehicle.Spanish Ministry of Economy, Industry and CompetitivenessThe European Regional Development Fund (DEP2016-75598-R)The European Regional Development Fund (ERDF) / Regional Ministry of Economic Transformation, Industry, Knowledge and Universities of Andalusia (B-CTS-160-UGR20),MCIN/AEI/10.13039/501100011033 and the European Union "ERDF A way of making Europe" (PID2021-126126OA-I00)Spanish Ministry of Science, Innovation and UniversitiesBiomedicine Doctoral Studies program of the University of Granada, Spai

Cycling area can be a confounder and effect modifier of the association between helmet use and cyclists’ risk of death after a crash

The effect of helmet use on reducing the risk of death in cyclists appears to be distorted by some variables (potential confounders, effect modifiers, or both). Our aim was to provide evidence for or against the hypothesis that cycling area may act as a confounder and effect modifier of the association between helmet use and risk of death of cyclists involved in road crashes. Data were analysed for 24,605 cyclists involved in road crashes in Spain. A multiple imputation procedure was used to mitigate the effect of missing values. We used multilevel Poisson regression with province as the group level to estimate the crude association between helmet use and risk of death, and also three adjusted analyses: (1) for cycling area only, (2) for the remaining variables which may act as confounders, and (3) for all variables. Incidence–density ratios (IDR) and their 95% confidence intervals were calculated. Crude IDR was 1.10, but stratifying by cycling area disclosed a protective, differential effect of helmet use: IDR = 0.67 in urban areas, IDR = 0.34 on open roads. Adjusting for all variables except cycling area yielded similar results in both strata, albeit with a smaller difference between them. Adjusting for cycling area only yielded a strong association (IDR = 0.42), which was slightly lower in the adjusted analysis for all variables (IDR = 0.45). Cycling area can act as a confounder and also appears to act as an effect modifier (albeit to a lesser extent) of the risk of cyclists’ death after a crash

Individual and environmental factors associated with death of cyclists involved in road crashes in Spain: a cohort study

Objective To quantify the magnitude of associations between cyclist fatalities and both cyclist and environment related characteristics in Spain during the first 24 hours after a crash. Results Non-use of a helmet was directly associated with death (IDR 1.43, 95% CI 1.25 to 1.64). Among other cyclist characteristics, age after the third decade of life was also directly associated with death, especially in older cyclists (‘over 74’ category, IDR 4.61, 95% CI 3.49 to 6.08). The association with death did not differ between work-related cycling and other reasons for cycling. There was an inverse association with death for crashes in urban areas and on community roads. Any adverse meteorological condition also showed a direct association with death, whereas altered road surfaces showed an inverse association. Crashes during nighttime were directly associated with death, with a peak between 3:00 and 5:59 am (IDR 1.58, 95% CI 1.03 to 2.41). Conclusions We found strong direct and inverse associations between several cyclist and environment related variables and death. These variables should be considered in efforts to prioritise public health measures aimed at reducing the number of cycling-related fatalities.This work was partially supported by the National Council of Science and Technology of Mexico [doctorate grant number 410668]

Convergent Validation of a Self-Reported Commuting to and from School Diary in Spanish Adolescents

The aim of this study was to examine the convergent validity of self-reported diary times for commuting to and from school with device-measured positional data (Global Positioning System; GPS) in Spanish adolescents. Methods: Cross-sectional data were obtained from four Spanish public secondary schools in 2021, comprising 47 adolescents and 141 home-school and school-home trips. Participants self-reported the time they left and arrived at home and school through a commuting diary. They wore a GPS device recording the objective time during three trips (i.e., one home-school trip and two school-home trips). Agreement between commuting diary and GPS data regarding home-school trips and school-home trips was evaluated using Bland-Altman plots. Results: Total commuting time differed by 1 min (95% limits of agreement were 16.1 min and -18.1 min) between subjective and objective measures (adolescents reported 0.8 more minutes in home-school trips and 1 more minute in school-home trips compared to objective data). Passive commuters reported 0.7 more minutes and active commuters reported 1.2 more minutes in the total commuting time compared to objective data. Conclusions: Self-reported commuting diaries may be a useful tool to obtain commuting times of adolescents in epidemiological research or when tools to measure objective times are not feasible.Spanish Ministry of Economy, Industry and Competitiveness and the European Regional Development Fund (DEP2016-75598-R, MINECO/FEDER, UE)Spanish Ministry of Education and Vocational Training (FPU17/03934, FPU18/04251)University of Granada, Plan Propio de Investigación 2016, Excellence actions: Units of Excellence, Unit of Excellence on Exercise and Health (UCEES)Junta de Andalucía, Consejería de Conocimiento, Investigación y Universidades, European Regional Development Fund (ERDF), ref. SOMM17/6107/UGRInstituto de Salud Carlos III through the fellowship CP20/00178 European Social Fun

The Effect of a School-Based Intervention on Children’s Cycling Knowledge, Mode of Commuting and Perceived Barriers: A Randomized Controlled Trial

The low rates of active commuting to/from school in Spain, especially by bike, and the wide range of cycling interventions in the literature show that this is a necessary research subject. The aims of this study were: (1) to assess the feasibility of a school-based cycling intervention program for adolescents, (2) to analyse the effectiveness of a school-based cycling intervention program on the rates of cycling and other forms of active commuting to/from school (ACS), and perceived barriers to active commuting in adolescents. A total of 122 adolescents from Granada, Jaén and Valencia (Spain) participated in the study. The cycling intervention group participated in a school-based intervention program to promote cycling to school during Physical Education (PE) sessions in order to analyse the changes in the dependent variables at baseline and follow up of the intervention. Wilcoxon, Signs and McNemar tests were undertaken. The association of the intervention program with commuting behaviour, and perceived barriers to commuting, were analysed by binary logistic regression. There were improvements in knowledge at follow-up and the cycling skill scores were medium-low. The rates of cycling to school and active commuting to/from school did not change, and only the “built environment (walk)” barrier increased in the cycling group at follow-up. School-based interventions may be feasibly effective tools to increase ACS behaviour, but it is necessary to implement a longer period and continue testing further school-based cycling interventions.Spanish GovernmentEuropean Commission DEP2016-75598-RUniversity of Granada, Plan Propio de Investigacion 2016, Excellence actions: Units of Excellence; Unit of Excellence on Exercise and Health (UCEES)Junta de AndaluciaEuropean Regional Development Fund (ERDF), "R&D research staff contract, within the framework of the Spanish National Youth Guarantee" - Junta de AndaluciaEuropean Social Fund (ESF)Spanish Government FPU18/04251 FPU17/0393

Active commuting to school and associated health indicators: evaluation protocol of the PACO study Cycle and Walk to School and its implementation in secondary school

El presente estudio ha sido financiado por el Ministerio de Economía, Industria y Competitividad del Gobierno de España y el Fondo Europeo de Desarrollo Regional (DEP2016- 75598-R, MINECO/FEDER, UE). Se recibe una ayuda del Ministerio de Ciencia, Innovacioìn y Universidades del Gobierno de EspanÞa (FPU17/03934; FPU18/04251). Además, este estudio ha sido parcialmente financiado por la Universidad de Granada, Plan Propio de Investigación 2016, Acciones de excelencia: Unidades de excelencia; Unidad de Excelencia en Ejercicio y Salud (UCEES), y por la Junta de Andalucía, Consejería de Conocimiento, Investigación y Universidades, Fondo Europeo de Desarrollo Regional (FEDER), ref. SOMM17 / 6107 / UGR.Es fundamental elaborar un protocolo de evaluación para garantizar rigor y homogeneidad en cualquier estudio de investigación. Asimismo, se requieren consideraciones específicas si la investigación se desarrolla en contexto educativo y en diferentes centros educativos. Este trabajo tiene como objetivo describir el protocolo de evaluación del estudio de investigación titulado: Estudio PACO “Pedalea y Anda al Colegio”. Además, se aportan recomendaciones globales y aplicaciones prácticas en el contexto educativo. El principal objetivo del estudio PACO es fomentar el comportamiento de desplazamiento activo entre estudiantes de Educación Secundaria Obligatoria para mejorar los niveles de actividad física y otros indicadores de salud asociados. Por ello, el protocolo de evaluación incluye la metodología e instrumentos específicos para evaluar en los adolescentes variables como: 1) modo de desplazamiento al centro educativo y otros factores psicosociales asociados a dicho desplazamiento mediante el cuestionario PACO alumnos, 2) barreras familiares para el desplazamiento activo al centro educativo mediante el cuestionario PACO familias, 3) características antropométricas (peso, talla, perímetro de cintura y de cuello), 4) niveles de actividad física y gasto energético evaluados mediante acelererometría y 5) características de la ruta real casa-colegio registradas mediante Sistema de Posicionamiento Global. La transparencia en la metodología y logística necesaria para evaluar dichas variables en contexto educativo, es la clave para garantizar el rigor y la homogeneidad en futuras implementaciones, ya sean estas realizadas por investigadores o docentes. Finalmente, los datos obtenidos, serán fiables y relevantes para implementar estrategias educativas que fomenten la salud integral de los adolescentes.It is essential to develop an evaluation protocol to develop rigor and homogeneity in any research study. Likewise, some considerations are specifically needed if the research is carried out in an educational context and in different schools. This work aims to describe y the evaluation protocol of the research study entitled: PACO Study “Cycle and Walk to School”. In addition, it provides global recommendations and practical applications in the educational context. The main objective of the PACO Study is to promote the behaviour of active commuting among students of Compulsory Secondary Education to improve their physical activity levels and other associated health indicators. For this reason, the evaluation protocol includes the specific methodology and instruments for evaluating variables such as: 1) mode of commuting to school and other psychosocial factors associated with active commuting through the PACO student questionnaire, 2) family barriers to active commuting to school through the PACO families questionnaire, 3) anthropometric characteristics (weight, height, waist and neck circumference), 4) levels of physical activity and energy expenditure evaluated by accelerometry and 5) characteristics of the real home-school route through a Global Positioning System. The transparency in the methodology and logistic necessary to evaluate the variables in the educational context is key to evaluate the rigor and homogeneity in future implementations, whether they are carried out by researchers or teachers. Finally, the obtained data will be reliable and relevant to implement educational strategies in order to promote an integral health of the adolescents.Ministerio de Economía, Industria y Competitividad del Gobierno de España y el Fondo Europeo de Desarrollo Regional (DEP2016- 75598-R, MINECO/FEDER, UE)Ministerio de Ciencia, Innovacioìn y Universidades del Gobierno de España (FPU17/03934; FPU18/04251).Universidad de Granada Plan Propio de Investigación 2016, Acciones de excelencia: Unidades de excelencia; Unidad de Excelencia en Ejercicio y Salud (UCEES)Junta de Andalucía, Consejería de Conocimiento, Investigación y Universidades, Fondo Europeo de Desarrollo Regional (FEDER), ref. SOMM17 / 6107 / UG

Factores asociados a la letalidad por accidentes de tráfico en ciclistas en España (1993-2017)

La elaboración del documento ha sido financiada por el Consejo Nacional de Ciencia y Tecnología (CONACYT) de México, gracias a la beca número 410668, cuyo único beneficiario ha sido el doctorando Daniel Molina Soberanes.Introducción: A pesar de la disminución observada en la mortalidad por accidentes de tráfico (AT) en años recientes en España, el colectivo ciclista no ha mostrado el mismo comportamiento, llegando incluso a presentar una mayor mortalidad. Aunado a ello, existe un interés público para fomentar el uso de la bicicleta como medio de transporte sostenible, por lo que la mortalidad derivada de los accidentes en los que se involucren ciclistas podría incrementarse aún más. Objetivo: Identificar el sentido y cuantificar la magnitud de la asociación de los factores dependientes del ambiente y del ciclista con su riesgo de muerte tras verse implicados en accidentes de tráfico en España, con especial énfasis en el uso del casco. Metodología: Se diseñó un estudio de cohorte retrospectivo a partir de una serie de casos y se disgregó en dos sub-períodos (1993 – 2013 y 2014 – 2017). Para ello, se utilizó la base de datos de la Dirección General de Tráfico de España, con información sobre 90.582 ciclistas accidentados en el territorio peninsular, de los cuales fallecieron 1.882. Debido a la presencia de datos faltantes, se realizó un procedimiento de imputación múltiple por el método de las ecuaciones encadenadas. Se obtuvieron estimaciones crudas y ajustadas mediante regresiones de Poisson para las asociaciones entre cada variable independiente y el riesgo de fallecer, utilizando modelos multinivel, considerando tanto al ciclista como a la provincia como niveles de agregación. Se aplicaron modelos causales para identificar el valor del posible efecto del uso del casco sobre el riesgo de fallecer y se evaluó el efecto confusor y/o modificador de efecto que la zona en que ocurre el accidente podría introducir. Todos los análisis se realizaron con el paquete estadístico Stata versión 14. Resultados: Se observó que el riesgo de fallecer puede variar en función del tipo de accidente y de ciertas circunstancias ambientales imperantes al momento del AT, con un mayor riesgo para aquellos que se presentaron en carretera-travesía, fuera de intersecciones, bajo condiciones atmosféricas adversas, pero con una superficie de la vía sin alteraciones y durante las altas horas de la madrugada. Se observó también que la letalidad ha mostrado un decremento paulatino a lo largo de toda la serie temporal. Los ciclistas que mostraron un mayor riesgo de fallecer fueron los que tenían una mayor edad al momento del AT; los hombres; los que tenían una nacionalidad distinta a la española; y los que habían cometido alguna infracción. Nuestros resultados sugieren un efecto protector del uso del casco respecto del riesgo de fallecer, el cual es de una mayor magnitud si el AT se presentó en carretera-travesía que si lo hizo en zona urbana. De hecho, la zona en que se presentó el AT confunde precisamente a la asociación entre el uso del casco y el riesgo de fallecer, además de modificar su efecto. Conclusiones: Se identificaron distintos factores asociados con el riesgo de que un ciclista fallezca tras verse involucrado en un AT en España, ya sea el tipo de accidente, las condiciones ambientales o las características del propio ciclista. Dichas asociaciones se mantuvieron en ambos sub-períodos estudiados, principalmente para las características del AT. El uso del casco disminuyó entre un 0,3% y un 2,3% el riesgo de que el ciclista falleciera tras el AT, y la zona en que ocurrió fue el principal confusor de esta asociación.Introduction: Despite the decrease observed in road traffic crashes (TC) mortality in recent years in Spain, cyclists’ crashes have not shown the same tendency. They have even a higher mortality rate nowadays. In addition, there is a public interest in promoting the use of bicycles as a sustainable means of transport. This could lead to further increases in mortality rates from TC involving cyclists. Objective: To identify the direction and to quantify the magnitude of the association of environment- and cyclist-dependent factors with the risk of death after being involved in traffic crashes in Spain, with special emphasis on the use of helmets. Methodology: A retrospective cohort study was designed from a case series and broken down into two sub-periods (1993 - 2013 and 2014 - 2017). For this purpose, the database of the Spanish General Directorate of Traffic was used, with information on 90,582 cyclists involved in crashes on the spanish mainland, of whom 1,882 died. A multiple imputation procedure was performed using the chained equations method due to the presence of missing data. Crude and adjusted Poisson regression models were used to estimate the associations between each independent variable and the risk of death, using multilevel models, considering both cyclist and province as aggregation levels. Causal models were used to identify the magnitude of the possible effect of helmet use on the risk of death. We assessed the role of the area of the crash as a confounder and/or as an effect modifier of this association. All analyses were performed with the statistical package Stata 14. Results: The risk of death can vary according to the type of accident and environmental circumstances at the time of the TC, with a higher risk for those occurring on the road, outside intersections, under adverse weather conditions, with an unaltered road surface and during the early hours. It was also observed that fatality has shown a gradual decrease throughout the time series. Cyclists who showed a higher risk of death were those who were older at the time of the TC; males; those with a nationality other than Spanish; and those who had committed an offence. Our results suggest a protective effect of helmet use on the risk of death, which is of a greater magnitude if the TC occurred on the road than if it occurred in an urban area. In fact, the area in which the TC occurred is a confounder of the association between helmet use and the risk of death, as well as an effect modifier. Conclusions: We identified different factors associated with the risk of death after a cyclist is involved in a TC in Spain. These factors are either the type of accident, the environmental circumstances, or the characteristics of the cyclist himself. The associations found were maintained in both sub-periods studied. Helmet use decreased the risk of cyclist´s death after the TC by 0,3% to 2,3%, and the area in which the TC occurred was the main confounder of this association.Tesis Univ. Granada.Consejo Nacional de Ciencia y Tecnología (CONACYT) de México (410668

The clustering of physical activity and screen time behaviours in early childhood and impact on future health-related behaviours: a longitudinal analysis of children aged 3 to 8 years

Background: Meeting physical activity and screen time guidelines has been associated with improved health in children. Research has shown that lifestyle behaviours happen in combination and can be tracked into later life. Thus, a complex approach is needed to identify the effects of physical activity and screen time altogether. This study aims to identify clusters of both behaviours in a cohort of Irish 3-year-old children (n=8833) and determine the association with sociodemographic characteristics and behaviours at age 5 and 7-8. Methods: Data from the “Growing Up in Ireland” study collected between 2010 and 2016 was used in this study. Two-step cluster analysis was used to understand how physical activity and recreational screen time behaviours group together among 3-year-old children. Binary logistic regressions were conducted to examine if cluster place‑ ment at age 3 determined physical activity and recreational screen time behaviours at age 5 and 7-8 years, while controlling for gender of child, gender, age and employment status of the primary caregiver. Results: Six clusters were identified in 9771 (49.3% female) 3-year-old children with the majority falling into a “High Active & Mixed Screen Time” (23.2%). Those in the “High Active & Mixed Screen Time” cluster at age 3 were more likely to engage in all physical activities reported at age 5 (p<0.01) and age 7-8 (p<0.01) when compared to a “Low Active & Screen Time Exceed” cluster. Children categorised in a “Moderate Active & Screen Time Below” and “Moderate Active & Screen Time Exceed” were more likely to engage in the same physical activities at age 5 and 7-8 (p<0.05 - p<0.01). However, children in the latter cluster were also more likely (p<0.05) to play on a computer or tablet device. Conclusions: This paper highlights the importance of establishing positive health-related behaviours during early childhood, as this predicts future engagement in health-promoting activities. Regardless of screen time level, being part of a cluster with moderate or high levels of physical activity positively influences a child’s future physical activity at age 5 and again at age 7 -8 years. The multiple layers of influence on a child’s development should be leveraged to support the adoption of health-enhancing behaviours

¿Cuántas víctimas colaterales se asocian con los usuarios de la carreteraresponsables de los accidentes de tráfico?

We wish to thank the Spanish Directorate General of Traffic forallowing access to their database of traffic accidents with victims,and K. Shashok for improving the use of English in the manuscript.Objective: To estimate the number of collateral casualties associated with road users considered responsible for a road crash. Method: We analyzed the case series comprising all 790,435 road users involved in road crashes with victims in Spain from 2009 to 2013, recorded in a nationwide police-based registry. For each road user assumed to be responsible for a crash, we collected information relative to health outcomes in other people involved in it, and obtained the total number of collateral casualties per 100 road users considered responsible for the crash. We then estimated the strength of associations between sex, age and the number of collateral casualties generated by car drivers considered responsible for the crash, and calculated rate ratios and corresponding 95% confidence intervals. Results: Pedestrians responsible for crashes were associated with the lowest number of collateral casualties (13.1/100), whereas the highest number (153/100) was observed for bus drivers responsible for crashes. Car drivers were associated with 104.4/100 collateral casualties. The youngest and the oldest car drivers responsible for crashes were associated with 33% and 41% more deaths, respectively, than the 25-4 year old group. Male drivers were associated with 22% more collateral casualties than female drivers. Conclusions: Regardless of the type of road user who was responsible for a road crash, their active contribution to the crash led to an additional number of collateral casualties in other, non-responsible users. The number and severity of collateral casualties were related to the type of vehicle and the number of people involved. These results are potentially useful to support the need to promote safer driver practices among subgroups of high-risk drivers.Objetivo: Estimar el número de víctimas colaterales asociadas a los usuarios de las vías de tráfico respon-sables de una colisión. Método: Se estudió la serie de casos formada por los 790.435 usuarios de la vía implicados en accidentes de tráfico con víctimas en España, entre 2009 y 2013, recogidos en el Registro de Accidentes de Tráfico con Víctimas de la Dirección General de Tráfico. Para cada uno de los usuarios considerado responsable se recogió información sobre las consecuencias sanitarias para las otras personas implicadas en el mismo accidente, y se calculó el número total de víctimas colaterales por cada 100 usuarios responsables. A continuación se estimó la fuerza de asociación de la edad y el sexo de los conductores de turismo con el número de víctimas colaterales generadas por ellos, y se obtuvieron las correspondientes razones detasas y sus intervalos de confianza del 95%.Resultados: Los peatones responsables de atropellos se asociaron al menor número de víctimas colaterales (13,1/100), mientras que la cifra más alta de estas (153/100) se asoció a los conductores de autobús responsables del accidente. Los de turismo implicaron a 104,4/100. Los conductores de turismo más jóvenes (64 años) implicaron respectivamente un 33% y un41% más de víctimas colaterales que el grupo de 25-34 años. Los varones se asociaron a un 22% más de víctimas colaterales que las mujeres. Conclusiones: Independientemente del tipo de usuario responsable del accidente, su contribución activase asoció a un número adicional de víctimas colaterales, cuyas magnitud y gravedad dependieron sobre todo del tipo de vehículo conducido. Este trabajo puede ser útil para reforzar las actuaciones destinadas a prevenir la accidentalidad en los usuarios de alto riesgo

Asociación del tipo de vehículo con el riesgo de provocar una colisión entre vehículos

Agradecimientos: A la Dirección General de Tráfico, por habernos facilitado la consulta y el uso del Registro Espanol ˜ de Accidentes de Tráfico con Víctimas, sin el cual la elaboración de este trabajo no hubiera sido posible.Objetivo: Cuantificar la magnitud de la asociación entre el tipo de vehículo y la probabilidad de ser el responsable de una colisión entre dos o más vehículos. Método: A partir del registro de accidentes de tráfico con víctimas de la Dirección General de Tráfico (2014 y 2015) se disenó˜ un estudio de casos y controles emparejado. Los casos fueron los conductores infractores implicados en las 27.630 colisiones entre dos o más vehículos, en las que solo uno de los conductores implicados había cometido algún error de conducción o infracción. Cada caso se emparejó con los conductores no infractores de los vehículos implicados en el mismo accidente; en total se dispuso de 31.219 controles. Aparte de la comisión de infracciones y del tipo de vehículo implicado, se obtuvo información para otras características del conductor (edad, sexo, etc.) y del vehículo (antigüedad). Se calcularon odds ratios (OR) para cuantificar la asociación entre cada tipo de vehículo y la odds de ser el causante de la colisión, crudas y ajustadas (ORa) (regresión logística condicionada) por el resto de las variables recogidas. Resultados: En comparación con los turismos, se obtuvo un menor riesgo de provocar la colisión para bicicletas (ORa: 0,30), ciclomotores (ORa: 0,52) y autobuses (ORa: 0,63), y un mayor riesgo para furgonetas (ORa: 1,19) y vehículos todoterreno (ORa: 1,33). Conclusión: Los vehículos de dos ruedas y los autobuses tienen un menor riesgo de provocar colisiones que los turismos. Esta asociación es independiente de algunas características del conductor, así como de la antigüedad del vehículo.Objective: To quantify the magnitude of the association between the type of vehicle and the probability of being responsible for a collision between two or more vehicles. Method: From the registry of road crashes with victims maintained by the Spanish Traffic General Directorate (2014 and 2015), a matched case-control study was designed. Cases were offending drivers involved in the 27,630 collisions between two or more vehicles in which only one of the drivers had committed a driving mistake or offence. Each case was matched with the non-offending drivers of the vehicles involved in the same crash: in all, 31,219 controls were included. Apart from the commission of offences and the type of vehicle involved, we got information about other characteristics of the driver (age, sex, etc.) and about the vehicle (age). Odds ratios (OR) were calculated in order to quantify the association between each type of vehicle and the odds of being responsible for the collision, crude and adjusted (by conditioned logistic regression) by the rest of collected variables. Results: In comparison with private cars, bicycles had a lower risk of causing a collision (adjusted OR: .30), and also mopeds (aOR: .52) and buses (aOR: .63). Vans (aOR: 1.19) and four-wheel vehicles (aOR: 1.33) increased the risk. Conclusion: Two-wheeled vehicles and buses had a lower risk of causing collisions than private cars. This association is independent of some of the characteristics of the driver, as well as the age of the vehicle