Table 4.

Within and Between Class Change in Days Abstinent at End of Treatment and 3- and 6-month Follow-up Assessments

	End of treatment		3-mos follow-up		6-mos follow-up
	Est. (SE)	Wald	Est. (SE)	Wald	Est. (SE)	Wald
Within class change in days abstinent by time point
Baseline
Class 1 (HA-MI)	.55 (.27)	4.27*	.57 (.29)	3.94*	.63 (.27)	5.49*
Class 2 (LA-SI)	1.22 (.32)	14.24***	.91 (.33)	7.77**	.69 (.37)	3.58
Class 3 (NA-AI)	2.22 (.41)	28.80***	2.24 (.39)	32.19***	2.31 (.40)	33.34***
Between class change in days abstinent slope by time point
Baseline
Class 1 v. Class 2	.67 (.42)	2.56	.34 (.43)	.61	.06 (.45)	.02
Class 1 v. Class 3	1.67 (.49)	11.51***	1.67 (.49)	11.71***	1.68 (.48)	12.15***
Class 2 v. Class 3	1.00 (.53)	3.61	1.33 (.51)	6.73**	1.62 (.54)	8.90***

^*p < .05

^**p < .01

^*** p < .001.

Note: Class 1= High Abstinence-Minimal Increase; Class2 = Low Abstinence-Steady Increase; Class 3= Non-abstinence-Accelerated Increase