Montréal Crossing - The Hazards of Intersections

1. Xing Jian Liu (M3 – McGill University) Dr. David Kaiser (R5 – PHPM) Faculty Supervisor: Dr. Joseph Cox (MScPH Program, McGill University) Montréal Crossing - The Hazards of Intersections

2. Introduction

3. Learning objectives • Recognize the public health importance and describe the epidemiology of traffic-related injuries. • Have an awareness of current sources of health data regarding traffic-related injuries and recognise the advantages and disadvantages of each of them. • Define the concept of risk factor and distinguish between modifiable and non-modifiable risk factors for traffic-related injuries. • Describe the concepts of incidence proportion, incidence rate, and prevalence, and understand the data needed to calculate each.

4. Learning objectives • Define the concept of stages of prevention (primary, secondary and tertiary) at a population level, and formulate preventive measures. • Name and describe two common frameworks applied to core public health functions such as health protection and injury prevention. • Describe the advantages and disadvantages of active and passive approaches to prevention. • Apply the concepts of stages of prevention, active v. passive strategies, and the epidemiologic triad to the classification of potential interventions to reduce traffic-related injuries.

5. Scenario You are a Health Sciences student at McGill University and you have just started the academic year. You moved to Montreal for school and you are excited about living in the Belle Province and learning some French. Also, Montreal is an exciting and busy city with lots of options for activities (walking in Mont Royal Park, great nightlife and food, etc.). You find yourself downtown after going to the bookstore and you are making your way to Ste. Catherine street. You are approaching the intersection of Sherbrooke and Peel streets where you witness a pedestrian halfway into the intersection yelling at a driver in a BMW (usual behaviour for pedestrians and bikers making their way through downtown Montreal). It seems the pedestrian, who looks to be a fellow student, was almost hit while crossing Sherbrooke, going in the same direction that you planned to go.

6. Scenario You think to yourself, “Wow! That was a close call! That could have been me!” You also start to wonder… • How often does this type of “close encounter” happen? • Are a lot of people injured at this intersection? • Why do these ‘close encounters’ and injuries happen? • Is this a public health issue, and if it is, is there anything we can do about it?

7. Traffic-related injuries: epidemiology • Mortality • 9thleading cause of death worldwide • in Canada, leading cause of mortality in children and adults <35 years of age • annual global mortality projected to increase from 1.3 million in 2004 to 2.4 million in 2030 Sources: WHO (2004), Statistics Canada (2011)

8. Traffic-related injuries: epidemiology • Morbidity • 9th leading cause of disability-adjusted life-years (DALY) lost • 20-50 million injuries per year • globally, most occur amongst pedestrians, cyclists or “motorized 2-wheelers” • in North America, the majority are amongst motor vehicle occupants Sources: WHO (2004), Statistics Canada (2011)

9. Pedestrian injuries: epidemiology • In Canada, 95% occur in an urban area (1992-2001) • More likely to result in hospitalisation or death than injuries to motor vehicle occupants • In Montreal, 1500-1800 traffic-related injuries per year occur among pedestrians • For each recorded injury, there are many more people with minor injuries or psychological effects due to near misses and perceived lack of safety Source: BC Public Service Agency Sources: Transport Canada (2004), Direction de santé publique de Montréal (2005)

10. Traffic-related injuries: risk factors • “an aspect of personal behaviour or lifestyle, an environmental exposure, or an inborn or inherited characteristic which on the basis of epidemiological evidence is known to be associated with health-related conditions considered important to prevent.” • According to this definition, no distinction is made between determinants of health and risk factors Last, Dictionary of Epidemiology

11. Traffic-related injuries: sources of data • Administrative databases • indicator of morbidity: emergency room visits, hospitalisations • pros: easy access, comparable over time, fairly complete for more severe injuries • cons: misses many minor injuries and property-damage only (PDO) collisions; no information on circumstances of collision • Death registries • indicator of mortality • pros: exhaustive (for mortality) • cons: the tipof the iceberg!!

12. Traffic-related injuries: sources of data • Insurers (government or private) • indicator of morbidity: collisions involving property damage, injuries receiving compensation • pros & cons: similar to administrative databases, although events included will differ • Police reports & ambulance transports • indicator of morbidity: collisions for which police/ambulance were called • pros: more likely to capture minor injuries and PDO collisions, circumstances of the collision & precise localisation • cons: don’t capture near-misses, may be less likely to capture cyclist injuries

13. Field exercise: research question What are the observable factors that may influence the occurrence of traffic-related injuries among pedestrians at intersections in downtown Montreal [or another city, if applicable]? • Outcome: Injuries, collisions, and near misses • Target population: Pedestrians crossing intersections in an urban setting • Study population: Pedestrians crossing 2 specific downtown Montreal [or another city, if applicable] intersections • Sample: Pedestrians crossing 2 specific downtown intersections in a span of 30 minutes

14. Field Exercise: objectives • Observe and record injuries, collisions, and “near misses” • A near miss is an unplanned event that does not result in injury, e.g., a pedestrian sees a car at the last minute and jumps out of the way • Observe and record factors that may be associated with the number of traffic-related pedestrian injuries • Identify actual and potential preventive interventions • Thinking broadly of interventions at multiple levels

15. Field Exercise: instructions • Each team will receive a package containing • Pencil & clipboard • Map of your 2 intersections • for Montreal intersections: • Team 1: Pine/St-Urbain and Roy/Henri-Julien • Team 2: University/Sherbrooke and Hutchison/Milton • Team 3: Sherbrooke/Peel and Maisonneuve/Mackay • Tables 1 & 2 • While walking there, you should start thinking about: • things you might want to observe at each intersection • how you will divide up the work • interventions to reduce pedestrian ‘near misses’, collisions & injuries at intersections • Spend around 30 minutes observing each intersection

16. Field Exercise: instructions • Fill out Table 1 with factors that you feel might be associated with the occurrence of pedestrian injuries at each intersection • In Table 2: • Note any interventions that you observe and potential interventions you think might reduce the number of pedestrian injuries at each intersection • Note any injuries, collisions or near misses observed, as well as the circumstances of these events • Have one member of the team report back about the team’s findings at the debrief session

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