Introduction

The nicotine metabolite ratio (NMR) of 3'-hydroxycotinine to cotinine is a noninvasive marker of the rate of nicotine metabolism. Fast metabolism (ie, a high NMR) is associated with lower cigarette smoking abstinence rates using transdermal nicotine replacement. We evaluated whether the NMR can be used to predict self-reported nicotine lozenge use and tobacco abstinence among smokeless tobacco users treated for tobacco dependence.

Methods

This was a secondary analysis of data from one arm of a large trial. Participants received quitting support materials and 4-mg nicotine lozenges by mail plus three coaching phone calls. Saliva kits were mailed for collection of saliva samples, which were analyzed for cotinine and 3'-hydroxycotinine. Self-reported tobacco and lozenge use were assessed at 3 months. Analyses were performed using Spearman rank correlation and logistic regression.

Results

Of the 160 saliva collection kits mailed, 152 were returned. The NMR was not significantly correlated with the baseline amount of smokeless tobacco used, the number of years of tobacco use, or the level of tobacco dependence as measured by the Severson Smokeless Tobacco Dependency Scale. The NMR was positively correlated with lozenge use (r = 0.21, P = .015), but it did not predict self-reported 7-day point prevalence abstinence at 3 months.

Conclusions

Fast metabolizers may need to self-administer more nicotine replacement in the form of nicotine lozenges to achieve the same clinical response achieved by slower metabolizers using fewer lozenges.

Background

Use of smokeless tobacco (moist snuff and chewing tobacco) is a significant public health problem but smokeless tobacco users have few resources to help them quit. Web programs and telephone-based programs (Quitlines) have been shown to be effective for smoking cessation. We evaluate the effectiveness of a Web program, a Quitline, and the combination of the two for smokeless users recruited via the Web.

Objectives

To test whether offering both a Web and Quitline intervention for smokeless tobacco users results in significantly better long-term tobacco abstinence outcomes than offering either intervention alone; to test whether the offer of Web or Quitline results in better outcome than a self-help manual only Control condition; and to report the usage and satisfaction of the interventions when offered alone or combined.

Methods

Smokeless tobacco users (N= 1,683) wanting to quit were recruited online and randomly offered one of four treatment conditions in a 2×2 design: Web Only, Quitline Only, Web + Quitline, and Control (printed self-help guide). Point-prevalence all tobacco abstinence was assessed at 3- and 6-months post enrollment.

Results

69% of participants completed both the 3- and 6-month assessments. There was no significant additive or synergistic effect of combining the two interventions for Complete Case or the more rigorous Intent To Treat (ITT) analyses. Significant simple effects were detected, individually the interventions were more efficacious than the control in achieving repeated 7-day point prevalence all tobacco abstinence: Web (ITT, OR = 1.41, 95% CI = 1.03, 1.94, p = .033) and Quitline (ITT: OR = 1.54, 95% CI = 1.13, 2.11, p = .007). Participants were more likely to complete a Quitline call when offered only the Quitline intervention (OR = 0.71, 95% CI = .054, .093, p = .013), the number of website visits and duration did not differ when offered alone or in combination with Quitline. Rates of program helpfulness (p <.05) and satisfaction (p <.05) were higher for those offered both interventions versus offered only quitline.

Conclusion

Combining Web and Quitline interventions did not result in additive or synergistic effects, as have been found for smoking. Both interventions were more effective than a self-help control condition in helping motivated smokeless tobacco users quit tobacco. Intervention usage and satisfaction were related to the amount intervention content offered. Usage of the Quitline intervention decreased when offered in combination, though rates of helpfulness and recommendations were higher when offered in combination.

Trial registration

Clinicaltrials.gov NCT00820495; http://clinicaltrials.gov/ct2/show/NCT00820495.