Street-view measures of urban greenness, area-level deprivation, and the risk of firearm-related homicide: A matched case-control study

Source abstract

The relationship between pedestrian-level exposure to green space in different social contexts remains unexplored. We examined 899 firearm-related and 2,256 natural deaths in Cook County, Illinois, using a retrospective matched case-control design. Greenness was assessed using the Normalized Difference Vegetation Index near death locations, tree canopy coverage, green space along walkable streets, and proximity of death to parks. Two additional greenness measures were derived from Google Street View images, analyzed using machine learning techniques. Associations were evaluated using Wilcoxon rank-sum tests and conditional logistic regression, adjusting for area-level deprivation and racial composition. The green view index derived from street-view imagery (OR = 0.693, p = 0.004), the greenness of walkable streets (OR = 0.787, p = 0.017), and tree canopy coverage (OR = 0.792, p = 0.029) were inversely associated with firearm-related homicide risk. Higher tree canopy coverage (OR = 0.213, p = 0.040) and Segmented Green Space Index (GSI) (OR = 0.552, p = 0.033) provided greater protective effects in less deprived neighborhoods. Street-level green space is associated with lower odds of homicide and its protective effects are moderated by neighborhood socioeconomic context.