Table 5. Hierarchical linear model testing impact of an alcohol-focused BMI on marijuana use frequency.

	B	SE	t-ratio	p
Intercept (pre-BMI)	13.60	1.14	11.95	<0.001
Gender	-3.68	1.76	-2.10	0.04
Condition	0.73	1.77	0.41	0.68
3-month follow-up	-2.00	0.90	-2.22	0.03
Gender	-1.65	1.36	-1.22	0.22
Condition	-0.35	1.38	-0.25	0.80
6-month follow-up	-2.24	1.23	-1.82	0.07
Gender	-2.13	1.74	-1.23	0.22
Condition	2.04	1.84	1.11	0.27
9-month follow-up	-2.38	1.32	-1.81	0.07
Gender	-2.16	1.82	-1.19	0.24
Condition	0.90	1.96	0.46	0.64

Note. Degrees of freedom = 225. BMI = Brief Motivational Intervention condition. MJ = marijuana. Assessment only was coded as 0; BMI was coded as 1. Gender was coded as 0 for males and 1 for females. HLM model equation is shown below, with coefficients corresponding to those listed in the table.

Level-1 Model

MJfrequency_ti = π_0i + π_1i*(3moFU _ti) + π_2i*(6moFU _ti) + π_3i*(9moFU _ti) + e_ti

Level-2 Model

π_0i = β₀₀ + β₀₁*(GENDER_i) + β₀₂*(CONDITION_i) + r_0i

π_1i = β₁₀ + β₁₁*(GENDER_i) + β₁₂*(CONDITION_i) + r_1i

π_2i = β₂₀ + β₂₁*(GENDER_i) + β₂₂*(CONDITION_i) + r_2i

π_3i = β₃₀ + β₃₁*(GENDER_i) + β₃₂*(CONDITION_i) + r_3i