Table 2.

Relative risk of initiation of alcohol use after baseline^a

Independent variables (at baseline)	Model 1 Relative riskb [95% CI]	Model 2 Relative risk [95% CI]	Model 3 Relative risk [95% CI]	Model 4 Relative risk [95% CI]
Main predictor
Trauma exposure and level of PTSD symptoms (ref. = no traumatic events)
Low PTSD symptoms (<5)	1.16	1.08	1.02	1.06
	[0.56, 2.42]	[0.51, 2.31]	[0.48, 2.15]	[0.50, 2.25]
High PTSD symptoms (≥5)	3.13***	2.48**	2.49**	2.29*
	[1.75,5.60]	[1.28, 4.77]	[1.31, 4.75]	[1.19, 4.41]
Control variables
Agec		1 99***	1.96***	1.91***
		[1.66,2.39]	[1.62, 2.36]	[1.57, 2.31]
Girl		1.32	1.26	1.48
		[0.84, 2.08]	[0.82, 1.95]	[0.92, 2.38]
Parental education (ref. = college)
No high school		0.82	0.83	1.04
		[0.41, 1.65]	[0.42, 1.65]	[0.51, 2.12]
High school		0.99	1.11	1.20
		[0.57, 1.70]	[0.63, 1.95]	[0.67, 2.13]
Single parent		0.93	0.90	0.82
		[0.62, 1.41]	[0.60, 1.35]	[0.54, 1.23]
Parental emotional problems			0.85	0.72
			[0.56, 1.30]	[0.46, 1.13]
Parental monitoringc			0.89**	0.92§
			[0.81, 0.97]	[0.84, 1.02)]
Child antisocial behaviorc				1.39***
				[1.17, 1.65]

Notes: CI = confidence interval; ref. = reference; PTSD = posttraumatic stress disorder.

^aDerived from proportional hazards model

^brelative risk adjusting for site and other factors in the model

^ccontinuous variables.

^§p < .10;

^*p <.05;

^**p < .01;

^***p < .001.