Table 3.

Models estimating racial/ethnic differences⁶ in associations of ZIP code-level racial/ethnic concentration and county-level mortgage discrimination with racial/ethnic homophily in sexual partnerships among people who inject drugs (n = 7847) living in 19 US cities in 2012

	Odds ratio (95% CI)	Odds ratio (95% CI)	Odds ratio (95% CI)	Odds ratio (95% CI)
Participant characteristics
Race/ethnicity
White (reference)	1.00	1.00	1.00	1.00
Black	1.62 (1.39, 1.88)*	1.84 (1.58, 2.14)*	2.53 (1.27, 5.07)*	5.40 (3.08, 9.46)*
Latino	0.75 (0.65, 0.88)*	0.55 (0.47, 0.65)*	3.27 (1.82, 5.89)*	1.53 (0.97, 2.42)
Place characteristics
Zip code (N = 889)
Concentration of Black vs. White residents
Interactions
White PWID (reference)	0.55 (0.48, 0.62)*
Black PWID/White PWID	3.17 (2.71, 3.71)*
Latino PWID/White PWID	2.68 (2.24, 3.21)*
Concentration of Latino vs. White residents
Interactions
White PWID (reference)		0.64 (0.58, 0.72)*
Black PWID/White PWID		1.88 (1.61, 2.18)*
Latino PWID/White PWID		2.74 (2.38, 3.15)*
County (N = 53)
Mortgage discrimination against Black residents
Interactions
White PWID (reference)			1.25 (1.03, 1.51) *
Black PWID/White PWID			0.90 (0.78, 1.05)
Latino PWID/White PWID			0.68 (0.60, 0.77)*
Mortgage discrimination against Latino residents
Interactions
White PWID (reference)				1.17 (0.94, 1.45)
Black PWID/White PWID				0.71 (0.61, 0.82)*
Latino PWID/White PWID				0.77 (0.68, 0.87)*

⁶Interaction models were separately run for each measure of racial/ethnic concentration and mortgage discrimination. White PWID serve as the reference group for all interactions. Standardized adjusted odds ratios are presented. Asterisk denotes p < 0.05