Table 3.

Linear regression of participant potential spatial access to oncology care on census tract percent Black among female patients diagnosed with breast cancer in GA from 1999 to 2003

	Intercept	Coeficient	SE	P value
Less distance decay (friction parameter = 1)
All women	−10.29	0.0920	0.0013	<0.0001
White women	−10.26	0.0290	0.0022	<0.0001
Black women	−9.73	0.0437	0.0022	<0.0001
More distance decay (friction parameter = 2)
All women	−11.00	0.1403	0.0031	<0.0001
White women	−11.03	0.1160	0.0056	<0.0001
Black women	−10.43	0.0786	0.0055	<0.0001

Potential spatial access is measured with gravity-based modeling of oncology supply, potential demand (population density), distance from patient to oncology services, and a distance decay function (‘friction parameter’). Resulting values were small and skewed, and thus log-transformed for modeling. Friction of 1 indicates less influence of travel distance on access; friction of 2 is greater influence of travel distance on potential access