Table 4. Multivariate Linear Regression results^a for density of and distance to food outlets for tribal areas^b compared to non-tribal areas^c.

	Healthy Outlets Composite	Supermarkets, Superstores & Produce Markets	Healthy Specialty Stores	Unhealthy Outlets Composite	Fast Food	Carry-out Restaurants & Unhealthy Specialty Stores	Convenience Stores & Gas Stations	Intermediate Outlets Composite	Sit-down Restaurants	Mixed-Specialty Stores
Densityd
β (95%Confidence Interval)
Tribal Areasb	-0.063 (0.11, -0.015)*	-0.051 (-0.088, -0.013)*	-0.011(-0.017, -0.0055)*	-0.20 (-0.47, 0.073)	-0.082 (-0.17, 0.003)+	-0.066 (-0.16, 0.031)	-0.053 (-0.091, -0.015)*	-0.14 (-0.42, 0.14)	-0.14 (-0.40, 0.13)	-0.0057 (-0.0088, -0.0027)*
Constant (Non-tribal Areasc)	0.25 (0.25, 0.26)*	0.20 (0.19, 0.20)*	0.034 (0.034, 0.035)*	1.2 (1.2, 1.3)*	0.42 (0.41, 0.43)*	0.41 (0.39, 0.42)*	0.21 (0.20, 0.21)*	1.1 (1.0, 1.1)*	1.0 (1.0, 1.1)*	0.017 (0.017, 0.018)*
Distancee
β (95%Confidence Interval)
Tribal Areasb	-0.20 (-0.81, 0.42)	-0.22 (-0.83, 0.39)	7.3 (5.4, 9.2)*	1.7 (0.93, 2.5)*	3.1 (2.2, 4.0)*	2.0 (1.1, 2.9)*	2.5 (1.6, 3.3)*	0.51 (-0.095, 1.1)+	0.51 (-0.10, 1.1)	9.7 (7.3, 12.1)*
Constant (Non-tribal Areasc)	1.9 (1.8, 2.0)*	2.0 (1.9, 2.1)*	3.8 (3.5, 4.2)*	1.9 (1.8, 2.1)*	2.4 (2.2, 2.5)*	2.4 (2.3, 2.6)*	2.3 (2.1, 2.4)*	1.8 (1.7, 1.9)*	1.8 (1.7, 1.9)*	6.0 (5.6, 6.5)*

* p <0.05 + p<0.1

^a Regression model is adjusted for per capita income and percent of the population living in urban areas; distance regressions (n = 2378) and density regressions (n = 2352). All numbers were rounded to two significant digits

^b In the distance analyses, tribal areas refer to “tribal census tracts” as defined by the US Census including primarily the land area of federally recognized American Indian reservations or off-reservation tribal lands. In the density analyses, tribal areas refer to census tracts that contain tribal lands

^c Non-tribal areas refer to matched census tracts without tribal lands that belong to counties with tribal lands

^d Density of food outlets per square mile was obtained for each census tract using the kernel density estimation

^e Distance is calculated as the shortest distance along the road network from the tribal census tract centroid to the closest food outlet of the respective category