Figure 1. Mean number^a of fast food restaurants near schools,^b according to neighborhood income tertiles,^c for all schools and stratified by school racial/ethnic composition of the student body^d and urbanicity.^e.

Notes: These p-values are for test of interaction assessing differences in school-neighborhood income gradient in fast food restaurant availability between 2000 and 2010 for schools overall and within each racial/ethnic majority group of schools.

^aEstimated from negative binomial regression models that included the main effects of neighborhood income tertiles and year, plus a cross-product term between the two.

^bData source: California public school data files, available on the California Department of Education’s website.^33,34

^cNeighborhood income tertiles are based on median annual household income tertiles (based on U.S. Census 2010 data).^36,37

^dMajority racial/ethnic composition of the student body refers to >50% of the student body in a racial/ethnic classification (based on data from the California Department of Education, 2010).³⁴

^eUrbanicity refers to urban or non-urban (rural, suburban, second city) households in the census tract in which schools were located (based on data from Nielsen PRIZM urbanization measures, 2013).³⁸

^fThis group has small sample sizes (n≤25) in some of the income tertiles in non-urban and/or urban areas, thus estimates should be interpreted with caution.