Table 2.

Bivariate and multivariate Cox regression analysis of factors associated with crystal methamphetamine initiation in street-involved youth.

	Unadjusted		Adjusted
Characteristic	Relative hazard (95% CI)	p Value	Relative hazard (95% CI)	p Value
Age at interview (yes versus no)	0.93 (0.84–1.03)	0.157
Male (yes versus no)	1.70 (0.86–3.34)	0.126	2.12 (1.06–4.25)	0.035
Caucasian (yes versus no)	1.08 (0.60–1.93)	0.809
Homelessnessa (yes versus no)	1.69 (0.93–3.07)	0.084
Injection drug use (yes versus no)	2.15 (1.09–4.27)	0.028
Daily marijuana use (yes versus no)	1.18 (0.65–2.15)	0.584
Cocaine useb (yes versus no)	1.86 (1.02–3.38)	0.043
Crack cocaine smoking (yes versus no)	3.35 (1.72–6.53)	<0.001	2.24 (1.20–4.20)	0.012
Heroin use (yes versus no)	1.63 (0.82–3.23)	0.162
Alcohol use (yes versus no)	1.23 (0.55–2.76)	0.610
Nonfatal overdose (yes versus no)	4.34 (2.08–9.09)	<0.001	3.63 (1.65–7.98)	0.001
Unsafe sex (yes versus no)	1.06 (0.59–1.89)	0.847
Mental illness diagnosis (yes versus no)	1.62 (0.90–2.88)	0.104
Police encounter (yes versus no)	2.04 (1.10–3.77)	0.023	1.66 (0.88–3.14)	0.118
History of sexual abuse (yes versus no)	0.74 (0.35–1.54)	0.414
History of physical abuse (yes versus no)	1.49 (0.81–2.73)	0.197
Sex work (yes versus no)	1.67 (0.59–4.71)	0.334
Drug dealing (yes versus no)	3.05 (1.70–5.46)	<0.001	1.98 (1.05–3.71)	0.034

^aAll behavioral variables refer to the past 6 months.

^bPowder by any route.