Evaluating the impact of social determinants on pedestrian injury in Clark County, Nevada

Background/Purpose While much is known about the impacts of roadway factors on pedestrian injury, less is known about the impacts of social determinants such as neighborhood demographics, socioeconomic factors, and characteristics of the built environment. Methods Police reported pedestrian crash data were linked by census tract to associated social determinants for Clark County, NV. Measures of social determinants were obtained from Census and county assessor data. For each tract, pedestrian injury and fatal crash rates were calculated. Stepwise multiple linear regression was applied to explore the relationship between the criterion variables, pedestrian crash and fatality rates; and the predictor variables of neighborhood demographic, socioeconomic factors, and characteristics of the built environment. Results Our final model was significant and described 58.2% of the variance in the pedestrian crash rate (r2=.582,p<0.001). Predictor variables which demonstrated larger influences on the criterion variable included those associated with: percent of households without a vehicle (B=9.18,p<0.001), population density (B=-4.6,p<0.001), liquor outlet density (B=1.85,p<0.0001), transit stop density (B=0.83,p<0.001) and the percent of the population who walk or use public transit (B=0.16,p<0.001). Conclusion Social determinants such as being foreign born, poverty, and education did not impact pedestrian crash rates. Social determinants of percent of households without a vehicle and liquor outlet density, and measures of exposure such as lack of access to motor vehicles, self reported walking, or transit use were associated with increased crash rates. Environmental characteristics which predicted crash rates included transit stop density. Population density was a protective factor.