. 2015 Apr 28;2015:730291. doi: 10.1155/2015/730291

Table 2.

Hierarchical multiple regression between smoking severity and PANSS scores.

	Nonsmoker	Mild-moderate nicotine dependence	Severe nicotine dependence	N − M Mean difference	N − S Mean difference	M − S Mean difference
	n = 112	n = 48	n = 21	N − M Mean difference	N − S Mean difference	M − S Mean difference
Total PANSS score, mean, ^amean (s.d)	49.13	51.56	51.43	0.62	1.16	0.54
Total PANSS score, mean, ^amean (s.d)	50.33^a (10.28)	49.71^a (12.21)	49.17^a (9.22)	(P = 0.98)	(P = 0.95)	(P = 0.97)

Positive subscale score, mean, ^amean (s.d)	8.54	9.65	9.76	−0.09	−0.04	0.05
Positive subscale score, mean, ^amean (s.d)	8.94^a (2.64)	9.04^a (3.09)	8.99^a (3.93)	(P = 0.88)	(P = 0.95)	(P = 0.98)

Negative subscale score, mean, ^amean (s.d)	18.01	17.13	14.67	1.89	4.54	2.64
Negative subscale score, mean, ^amean (s.d)	18.41^a (5.67)	16.52^a (6.45)	13.87^a (4.48)	(P = 0.26)	(^* P = 0.011)	(P = 0.06)

General psychopathology subscale score, mean, ^amean (s.d)	22.70	24.02	24.14	0.50	0.65	0.14
General psychopathology subscale score, mean, ^amean (s.d)	23.42^a (4.13)	22.92^a (6.27)	22.77^a (7.07)	(P = 1)	(P = 1)	(P = 1)

N, nonsmoker; M, mild-moderate nicotine dependence; S, severe nicotine dependence; and PANSS = Positive and Negative Syndrome Scale.

^* P < 0.05, ^** P < 0.01, s.d = standard deviation.

^aMultivariate analysis of covariance with PANSS total score and subscale scores as dependent variables; covariates appearing in the model are evaluated at the following values: gender = 1.36, ethnicity = 1.70, drug and alcohol abuse = 1.12, income = 1.25, and atypical antipsychotic = 1.55. These tests are based on the linearly independent pairwise comparisons among the estimated marginal means and adjusted for multiple comparisons using Bonferroni familywise error correction.