Pedestrian injuries in Mexico: a multi-method approach

Studies of road traffic injuries should identify social determinants amenable to intervention, and should attend to the problems of individual drivers and pedestrians. This is especially true in developing nations like Mexico, where traffic fatality rates are high and interventions ineffective. Objective: Combine qualitative and quantitative methods to analyze pedestrian injuries from motor vehicles in Mexico City, and identify their social, contextual and environmental determinants. Methods included (1) a cross-sectional analysis of mortality, producing crude and specific mortality rates and standardized mortality ratios (95% CI) by region; (2) Spatial analysis using a geographic information system to generate maps at different aggregation levels; (3) Observation with cameras to identify traffic patterns, spaces, behaviors, and patterned violations of regulations; and 4) Semi-structured in-depth interviews of pedestrians and drivers involved in an accident. Results: The overall crude mortality rate was 7.14/100,000, (CI 6.85-7.42), with differences by sex and region. The highest concentration of deaths was observed in 10 neighborhoods, at specific types of street environments. The high-risk environments have wide avenues with abundant vehicular traffic, where spaces supposedly reserved for pedestrians are invaded by cars and vendors. Many pedestrians have never driven a motor vehicle, few know the traffic signs, and almost all events were "hit and run" cases. Conclusions: The combination of quantitative and qualitative methods allows us to see the specific importance of some determinants of pedestrian injuries. Spatial, epidemiological, and social perspectives help point out the local accident characteristics which must be considered before defining preventive interventions.