TABLE 2.

Generalized Estimating Equations Models Evaluating Treatment Effects on Main and Process Outcomes

	AOD use (N = 163)
Predictors	IRR	CI (95%)	z	P
t	.10	.05–.24	−5.31	<.001
t2	1.80	1.42–2.27	4.86	<.001
Total treatment hrs	1.00	.97–1.03	−.04	.97
Race	1.02	.76–1.36	.10	.92
Treatment	.92	.67–1.25	−.54	.59
t × treatment	.14	.03–.70	−2.40	.02
t2 × treatment	1.91	1.16–3.15	2.55	.01
	Craving (N = 166)
Predictors	Exp(B)	CI (95%)	z	P
t	1.06	.76–1.47	.35	.73
t2	.95	.86–1.07	−.83	.41
Total treatment hours	.99	.97–1.01	−1.34	.18
Race	1.55	1.24–1.94	3.84	<.001
Treatment	.84	.66–1.06	−1.46	.14
t × treatment	.68	.49–.95	−2.27	.02
t2 × treatment	1.13	1.01–1.26	2.21	.03
	Acceptance (N = 163)
Predictors	β	CI (95%)	z	P
t	.03	−.26, .32	0.21	.84
t2	.06	−.25, .36	0.36	.72
Total treatment hours	−.05	−.18, .08	−.71	.48
Race	−.05	−.21, .10	−0.68	.50
Treatment	.03	−.14, .20	0.35	.73
t × treatment	.44	.01, .87	2.00	.045
t2 × treatment	−.40	−.80, −.01	−1.98	.047
	Acting with awareness (N =165)
Predictors	β	CI (95%)	z	P
t	−.48	−.85, −.11	−2.53	.01
t2	.52	.10, .93	2.44	.02
Total treatment hours	−.03	−.20, .13	−0.40	.69
Race	−.09	−.23, .06	−1.18	.24
Treatment	−.09	−.27, .09	−1.03	.30
t × treatment	.67	.15, 1.18	2.54	.01
t2 × treatment	−.61	−1.11, −.11	−2.43	.02

Note. For all models: t = linear time predictor (0 = baseline; 1 = posttest; 2 = 2-month follow-up; 3 = 4-month follow-up); t² = quadratic time predictor. IRR = incident rate ratio or the rate of increase/decrease outcome variable based on a one-unit change in the predictor, where IRR values greater than 1 indicate rate increases, and values less than 1 indicate rate decreases. Exp(B) = exponentiated gamma-log coefficient (values less than 1 represent inverse associations; values greater than 1 represent positive associations). β = standardized regression coefficient (negative values represent inverse associations; positive values represent positive associations). SE = bootstrapped standard error. CI (95%) = 95% confidence intervals. The treatment variable was dummy coded with MBRP treatment group = 1, TAU = 0. Self-reported race was dummy coded with 1 = White, 0 = non-White.

For alcohol and other drug use (AOD) model: An additional series of post hoc, cross-sectional, Poisson regressions tested treatment differences at each time point. The MBRP group reported significantly lower AOD use at both post-intervention (IRR = .02, P < .001) and 2 months post-intervention (IRR = .39, P < .001); however, this difference was reduced to nonsignificant at 4 months post-intervention (IRR = 1.11, P = .21).