Table 6.

Effects of Treatment among Full Sample and among Latent Classes in Study 2

	Post-Treatment Alcohol or Drug Use Days (AODD) as Outcome
	Effect of Treatment (Coded 0 = TAU, 1 = MBRP)	n (%) with zero AODD	Mean (SD)
Full Sample	B (SE) = −3.32 (0.66)**	MBRP only: 73 (94.8%)	MBRP only: 0.10 (0.30)
	p<0.001	TAU only: 47 (83.9%)	TAU only: 2.57 (9.08)
	IRR = 0.04
Low/low class	B (SE) = 2.32 (1.42)	MBRP only: 14 (87.5%)	MBRP only: 0.19 (0.54)
	p=0.103	TAU only: 8 (88.9%)	TAU only: 0.22 (0.67)
	IRR = 9.97
High/high Class and High/low class combined	B (SE) = −4.33 (0.85)**	MBRP only: 59 (96.7%)	MBRP only: 0.03 (0.18)
	p<0.001	TAU only: 39 (83.0%)	TAU only: 3.02 (9.86)
	IRR = 0.01

Note.

^*= p < .05;

^**= p < .01.

MBRP = Mindfulness-Based Relapse Prevention. TAU = Treatment as Usual. B =unstandardized regression coefficient; SE = standard error. IRR = Incidence Rate Ratio. IRR can be interpreted as the rate of increase (when the IRR is above 1.0) or the rate of decrease (when the IRR below 1.0) in heavy drinking or drug use days for a 1-unit increase in the predictor (with other predictors in the model held constant). All negative binomial regression models conducted among the full sample and within latent classes controlled for the following covariates: treatment hours completed and race (coded 1= non-Hispanic white, 0 = non-white).