Table 2.

Abstinence Rates Over Time by Dropout Pattern Within Study Arm

Study arm	Last visit attended	Abstinence rate (%)
		N	%	1 month	2 months	6 months	12 months
SC (N = 440)	Baseline	71	16.1
	1 month	30	6.8	40
	2 months	68	15.5	38	33
	6 months	63	14.3	37	37	20
	12 month	208	47.3	39	40	30	28
ME (N = 406)	Baseline	66	16.3
	1 month	38	9.4	37
	2 months	60	14.8	35	32
	6 months	74	18.2	42	37	24
	12 months	168	41.4	38	45	33	29

Note. Values in italics show study completers. ME = motivational enhancement; SC = standard care.