. Author manuscript; available in PMC: 2019 Jan 1.

Published in final edited form as: J Subst Abuse Treat. 2017 Nov 7;84:50–56. doi: 10.1016/j.jsat.2017.10.009

Table 2.

Tests of effects from the generalized linear mixed model of ASSIST GCIDR scores.

	(df_n, df_d)	χ²	p-value

CBI	(1, 346)	0.36	0.55
Gender	(1, 346)	2.81	0.09
Ethnicity	(1, 346)	0.15	0.70
Time	(3, 305)	33.99	<.001
CBI x Gender	(1, 346)	2.82	0.09
CBI x Ethnicity	(1, 346)	0.15	0.70
CBI x Time	(3, 305)	5.80	0.12
Gender x Ethnicity	(1, 346)	0.03	0.86
Time x Gender	(3, 305)	5.33	0.15
Time x Ethnicity	(3, 305)	13.50	0.004
CBI x Gender x Ethnicity	(1, 346)	1.15	0.28
CBI x Time x Gender	(3, 305)	4.18	0.24
CBI x Time x Ethnicity	(3, 305)	0.24	0.97
Time x Gender x Ethnicity	(3, 305)	1.69	0.64
CBI x Time x Gender x Ethnicity ¹	(3, 305)	9.23	0.03

Notes: ASSIST= Alcohol, Smoking, and Substance Involvement Screening Test. GCIDR= Global Continuum of Illicit Drug Risk. IBI= In-person Brief Intervention. CBI= Computerized Brief Intervention. df_n= numerator degrees of freedom; df_d = denominator degrees of freedom. Reference categories for CBI, Gender, Ethnicity, and Time are IBI, Male, Non-Hispanic, and Baseline, respectively.

Represents the primary effect of interest.