Of 175 screened subjects, 102 were randomized. Among the 73 subjects who failed to enter the study, 61 subjects did not return after the initial screening visit, 8 were excluded for medical reasons (7 for hypertension and 1 for chest pain), and 4 did not meet the minimum tobacco use requirement. A total of 23 subjects dropped out of the study (12 were in the behavioral intervention only group and 11 were in the lozenge group). Brand use varied significantly between groups ().
Demographics of ST users enrolled in study of ST reduction
Reductions in ST and toxicant exposure
Both interventions produced decreases in ST use, tobacco exposure, and toxicants, but no significant differences were observed between groups ().
The effects of lozenge and a behavioral intervention on ST use, tobacco exposure (cotinine), and toxicants (total NNAL) during treatment period (baseline to Week 8) and at 12-week follow-up. Missing values are replaced by baseline values.
For both groups, significant time effects were observed for tins per week (p < .001), dips per day (p < .001), cotinine (p < .001), and total NNAL (pmol/mg creatinine; p = .03, indicating a nonconstant time trend in these variables over the baseline and follow-up visits. A time-by-treatment interaction effect was observed (p = .03) with significantly higher cotinine levels in the lozenge group at Week 4 (difference = 2,115, p = .03) and marginally significantly greater reduction in cotinine in the lozenge group at Week 12 (difference in reduction = −1,642, p = .05) compared with baseline. No other significant treatment or time-by-treatment effects were observed.
At Week 8, a greater but not statistically significant proportion of subjects in the lozenge group achieved a ≥75% reduction in dips per day (32.1%) compared with the behavioral intervention group (16.7%, p = .08). A higher proportion of subjects in the lozenge group also achieved a ≥75% reduction in total NNAL (pmol/mg creatinine) at Week 8 (18.8% vs. 5.7%, p = .08). As expected, a higher percentage of subjects in the behavioral intervention group achieved a ≥50% reduction in cotinine at Week 4 (31.1% vs. 15.8%, p = .07) and ≥75% reduction in cotinine at Week 8 (11.1% vs. 5.3%, p = .28) compared with the lozenge group.
Significant time effects were observed for dips per day in both groups (p = .01), for cotinine in the lozenge group (p = .02) and for total NNAL (pmol/mg creatinine) in the lozenge group (p = .01), indicating that the reduction in these variables are not constant over the three follow-up visits. No other significant time, treatment, or time-by-treatment effects were observed.
Abstinence, quit attempts, and duration of abstinence
Both groups showed significantly increased proportions of self-reported 7-day abstinence with time (p < .001 and p = .01 for lozenge and the behavioral intervention group, respectively). The lozenge group doubled the proportion of self-reported 7-day abstinence as compared with the behavioral intervention group at Week 8 although the difference was not significant (lozenge vs. counseling: 14.0% vs. 6.7%, respectively, p = .34). No treatment-by-time interactions were observed.
Both groups showed a significantly increased proportion of quit attempts with time (p < .001). Approximately one third of subjects in each group had made quit attempts by Week 12 (lozenge vs. behavioral: 33.3% vs. 28.9%, respectively, p = .67). No treatment-by-time interactions were observed.
Both groups showed significantly increased duration of abstinence with time (p < .001). A trend was observed toward a longer duration of abstinence in the lozenge group compared with the behavioral intervention group (9.9 ± 17.3 [SD] days vs. 6.6 ± 15.1 days, p = .30). No treatment-by-time interactions were observed.
All subjects reported using lozenges from Weeks 1 to 7, and all subjects except one used lozenges during Week 8. At Weeks 1–4, subjects used a mean ± SD of 3.1 ± 1.6, 3.6 ± 2.0, 3.7 ± 1.8, and 4.1 ± 2.4 lozenges per day, respectively. At Weeks 5–8, subjects used a mean ± SD of 4.6 ± 2.7, 4.5 ± 2.4, 4.5 ± 2.6, and 5.1 ± 3.2 lozenges per day, respectively.