. Author manuscript; available in PMC: 2013 Aug 22.

Published in final edited form as: Psychol Addict Behav. 2011 Mar;25(1):80–89. doi: 10.1037/a0021874

Table 3.

Categorical Models of the Accuracy and Bias in Estimates of Peer Substance Use: Add-Health Data, N = 2194

Effect	Contrast	Tobacco Use			Alcohol Use			Marijuana Use

		Estimate	SE	χ²	Estimate	SE	χ²	Estimate	SE	χ²
Intercept	a vs. d	−0.65	0.13	23.21^**	−1.48	0.13	125.57^**	0.24	0.18	1.80
	b vs. d	−0.49	0.12	17.64^**	−0.03	0.08	0.18	−0.43	0.18	5.78^*
	c vs. d	−1.21	0.13	85.30^**	−2.08	0.15	190.79^**	−0.33	0.17	3.79
Use (No)	a vs. d	1.77	0.13	174.41^**	1.53	0.13	135.45^**	0.00	0.06	0.00
	b vs. d	1.18	0.12	102.20^**	0.96	0.08	158.48^**	0.04	0.07	0.42
	c vs. d	0.56	0.13	18.08^**	0.30	0.15	3.94^*	0.08	0.08	1.02
Gender (female)	a vs. d	−0.12	0.06	3.96^*	0.77	0.13	34.49^**	1.70	0.13	165.08^**
	b vs. d	−0.02	0.06	0.13	0.47	0.08	38.06^**	1.34	0.12	121.58^**
	c vs. d	−0.02	0.08	0.05	0.24	0.15	2.49	0.26	0.09	8.73^**
Age (12–14)	a vs. d	0.58	0.13	18.83^**	−0.09	0.13	0.47	1.07	0.13	65.26^**
	b vs. d	0.25	0.12	4.61^*	0.06	0.08	0.58	0.49	0.14	11.34^**
	c vs. d	0.20	0.13	2.29	−0.01	0.15	0.01	0.53	0.16	10.42^**
Use by age	a vs. d	0.14	0.13	1.17	−0.07	0.08	0.72	- ^a	- ^a	- ^a
	b vs. d	0.25	0.12	4.46^*	−0.11	0.05	4.04^*	- ^a	- ^a	- ^a
	c vs. d	0.22	0.13	2.88	0.01	0.10	0.01	- ^a	- ^a	- ^a

Note:

p < .05.

^**

p < .01.

Contrasts: a vs. d = Correct rejection vs. hit; b vs. d = miss vs. hit; c vs d = false alarm vs. hit

Effect not estimable due to sparse data.