. Author manuscript; available in PMC: 2016 Apr 1.

Published in final edited form as: Addiction. 2015 Apr;110(4):610–618. doi: 10.1111/add.12845

Table 2.

Results from multi-level regression analyses of social behavior alcohol expectancies on age and drinking status in 1292 adolescent twins measured up to three times from ages 11 to 18 years.

	Model A	Model B	Model C
Intercept	1.93 (0.033)^*	1.85 (0.034)^*	1.95 (0.041)^*
Age (years)	0.12 (0.007)^*	0.10 (0.008)^*	0.06 (0.011)^*
Drinking status	(–)	0.29 (0.034)^*	0.08 (0.056)
Age × drinking status	(–)	(–)	0.07 (0.014)^*
–2LL	5157.4	4979.6	4952.8
Δχ²/df	(–)	177.8/1	26.8/1

Results based on 2350 observations from 1292 individuals. Drinking status is coded 1 if the subject reported drinking onset prior to that assessment and 0 otherwise. Age is centered around 11 years. – = parameter not included in model. Δχ² is the difference in fit relative to the prior model.

Significance at P<0.05 level.

Multi-level regression was used to account for the nesting of multiple occasions within twins and of twins within pairs.