Figure 2.

Statistically significant clusters of all pharmacies (a), pharmacies that sold syringes over-the-counter (b), and sociodemographic variables (c–f) within Los Angeles County census tracts in 2008. Locations with red shading denote hot-spot clusters that had significantly higher values than the global mean value for all census tracts in LA County (p < 0.05). Yellow polygons denote census tracts that had values that were not statistically different from the global mean value. Polygons with blue shading denote cold-spots that had significantly lower values than the global mean (p < 0.05). Threshold distance 11,000 m (6.8 miles). Geographic coordinate system: NAD 1983, Projection: California Teale Albers.