Table 2.

Mean percentage reduction and proportion of subjects achieving at least a 50% reduction in baseline smokeless tobacco (ST) use by self-reported tobacco use and biomarkers of exposure.

Variable	Mean percentage reduction, % (SD)a		Percentage achieving at least 50% reduction at week 8		Percentage achieving at least 75% reduction at week 8
	Tobacco-free snuff	Control	Tobacco-free snuff (n=52)	Control (n=54)	Tobacco-free snuff (n=52)	Control (n=54)
Tins/week
Week 4	55.9 (15.0)	52.9 (12.7)	48.1	50.0
Week 8	80.2 (15.4)	77.8 (17.0)	71.2	57.4	23.1	18.5
Week 12	78.0 (26.1)	70.2 (23.4)	34.6	25.9
Dips/day
Week 4	56.4 (15.2)	51.1 (16.3)	44.2	42.6
Week 8	80.2 (17.8)	72.5 (18.7)	71.2	53.7	15.4	9.3
Week 12	71.5 (46.8)	66.6 (27.4)	23.1	24.1
Cotinineb,d
Week 4	37.9 (37.8)	23.7 (37.7)	30.8	16.7
Week 8	55.8 (41.1)	39.2 (51.9)	42.3	24.1e	25.0	13.0
Week 12	54.1 (59.5)	39.4 (47.5)	44.2	16.7f
Total NNALc,d
Week 4	29.3 (32.1)	18.5 (30.9)	15.4	7.4
Week 8	42.6 (46.9)	4.0 (66.4)	36.5	11.1f	23.1	9.3e
Week 12	35.5 (56.6)	−1.6 (111.8)	26.9	14.8

Note. SD, standard deviation.

^aExclusive of dropouts; subject sample size varies from 42 to 26, with higher numbers of subjects earlier in treatment.

^bTreatment effect for mean percentage reduction in cotinine concentrations, p=.026.

^cTreatment effect for mean percentage reduction in total NNAL concentrations, p<.001.

^dWhen analysis was conducted on intent-to-treat basis with missing data reset as baseline values, the results were similar to the analysis exclusive of dropouts, except significant time effects were not observed for cotinine and tins/day. Additional treatment effects were observed for tins/week (p=.014) and dips/day (p=.020), most likely due to the higher dropout rates in the control group.

^eTreatment effect for percentage who achieved at least 50% or at least 75% ST reduction, p⩽.05.

^fTreatment effect for percentage who achieved at least 50% ST reduction, p<.01.