. Author manuscript; available in PMC: 2013 Mar 13.

Published in final edited form as: Twin Res Hum Genet. 2010 Dec;13(6):550–558. doi: 10.1375/twin.13.6.550

Table 4.

Mediation Models for Inattentiveness: Regression Coefficients (β) and Odds Ratios (OR) with 95% Confidence Intervals in Parentheses

Inattentiveness	Direct effect: Inattentiveness → Drug use		Inattentiveness → Smoking		Smoking → Drug use		Indirect effect: Inattentiveness → Drug use
Boys (n = 1992)	β_dt/β_dp	OR	β_st/β_sp	OR	β_ds	OR	β_st/β_sp ^* β_ds	OR

Teacher ratings	0.17 (−0.08, 0.41)	1.18 (0.93, 1.51)	0.52 0.37, 0.67	1.68 (1.44, 1.96)	1.77 (1.42, 2.11)	5.86 (4.14, 8.28)	0.92 (0.60, 1.24)	2.51 (1.70, 3.31)
	(p = .177)		(p < .001)		(p < .001)		(p < .001)
Parental ratings	0.21 (−0.07, 0.49)	1.24 (0.93, 1.64)	0.60 (0.40, 0.79)	1.82 (1.50, 2.21)	1.78 (1.44, 2.12)	5.93 (4.21, 8.34)	1.07 (0.67, 1.46)	2.91 (1.75, 4.06)
	(p = .139)		(p < .001)		(p < .001)		(p < .001)

Girls (n = 2123)	β_dt/β_dp	OR	β_st/β_sp	OR	β_ds	OR	β_st/β_sp ^* β_ds	OR

Teacher ratings	0.39 (0.16, 0.62)	1.47 (1.17, 1.86)	0.73 (0.52, 0.93)	2.07 (1.69, 2.54)	1.78 (1.46, 2.11)	5.95 (4.32, 8.20)	1.30 (0.87, 1.73)	3.66 (2.08, 5.33)
	(p = .001)		(p < .001)		(p < .001)		(p < .001)
Parental ratings	0.46 (0.18, 0.74)	1.57 (1.20, 2.10)	0.69 (0.47, 0.91)	1.99 (1.59, 2.48)	1.80 (1.48, 2.12)	6.05 (4.40, 8.32)	1.24 (0.79, 1.69)	3.50 (1.90, 5.00)
	(p = .001)		(p < .001)		(p < .001)		(p < .001)