Table 1.

Summary of logistic regression analysis for variables predicting younger siblings’ alcohol use (n = 321)

	Model 1			Model 2			Model 3
Variable	B	OR	[95% CI]	B	OR	[95% CI]	B	OR	[95% CI]
Intercept	−3.66***			−4.01***			−3.89***
Family structure	0.29	1.35	[0.63, 2.87]	1.3	1.39	[0.65, 2.99]	0.55	1.73	[0.76, 3.94]
Parental knowledge	−1.03**	0.36	[0.17,0.76]	−1.08**	0.34	[0.16,0.74]	−1.04*	0.36	[0.16,0.80]
Sibling intimacy	0.02	1.03	[0.47, 2.25]	0.19	1.21	[0.54, 2.72]	0.26	1.30	[0.55, 3.03]
Sibling conflict	0.14	1.15	[0.65, 2.02]	0.14	1.50	[0.65, 2.03]	0.23	1.26	[0.68, 2.35]
Parent’s alcohol use	0.31	1.37	[0.95, 1.98]	0.27	1.31	[0.89, 1.93]	0.16	1.18	[0.77, 1.79]
Friends’ alcohol use	1.24***	3.46	[2.38, 5.03]	1.32***	3.76	[2.52, 5.60]	1.56***	4.76	[2.99, 7.57]
Sibling’s alcohol use (sib. alc.)	1.85***	6.33	[2.83, 14.12]	2.17***	8.72	[3.46,21.96]	1.75***	5.63	[2.35, 13.98]
Shared friends (shr. fr.)	0.14	1.15	[0.41,0.52]	0.141	1.15	[0.73,3.12]	−0.34	0.71	[0.31, 1.65]
Sibling modeling (mod.)	−0.13	0.88	[0.18,0.67]	−1.45*	0.23	[0.07, 0.75]	−1.49	0.23	[0.06, 0.84]
Sib. Alc. × Mod.				1.64**	5.15	[1.49, 17.79]	1.73*	5.63	[1.40,22.67]
Sib. Alc. × Shr. Fr.				−0.29	0.75	[0.31, 1.82]	0.53	1.70	[0.63, 4.57]
Mod. × Shr. Fr.				0.35	1.42	[0.84, 2.42]	−2.23**	0.11	[0.02, 0.58]
Mod. × Sib. Alc. × Shr. Fr.							3.38***	29.40	[4.41, 196.19]
χ2		107.81			116.18*			133.95***
df		13			16			17

Notes: Nonsignificant controls omitted from table: parental education, sex composition, age spacing, and gender. OR = odds ratio.

^*p < .05;

^**p <.01;

^***p < .001.