TABLE 3.

Effects of Network Properties on Amphetamine Use at 3 Months, United States and Australia

	Model 1			Model 2
Variable	Beta	Odds Ratio	95% Confidence Interval	Beta	Odds Ratio	95% Confidence Interval
Background characteristics
Age (years)	0.06	1.06	0.84, 1.34	0.08	1.08	0.87, 1.34
Gender (male = 1)	−0.32	0.73	0.36, 1.49	−0.61	0.54	0.26, 1.12
Site (United States = 1)	−0.80*	0.45	0.21, 0.95	−0.81*	0.45	0.21, 0.93
Baseline behavior (user =1)
Amphetamine user	2.29**	9.90	4.83, 20.29	2.62**	13.74	6.84, 27.63
Network properties
Concentration of injecting friends	0.46	1.59	0.79, 3.20
Change in concentration				0.42	1.52	0.86, 2.70
Concentration of homeless friends	0.73**	2.08	1.18, 3.65
Change in concentration				0.07	1.07	0.65, 1.79
Density	0.63*	1.88	0.94, 3.79
Hosmer-Lemeshow test
Chi-square	5.11			7.87
df	8			8
p > chi-square	0.75			0.45
−2 log likelihood	213.32			224.23

^*p < .05.

^**p < .01. One-tailed t test.