Snus undermines quit attempts but not abstinence: a randomised clinical trial among US smokers

Abstract

Background: Observational studies and a few clinical trials suggest that use of low nitrosamine smokeless tobacco (snus) can facilitate smoking cessation. To better understand the real-world impact of snus on smoking behaviour, a large-scale, long-term clinical trial of naturalistic snus use among smokers is needed.

Study design: A nationwide clinical trial compared abstinence outcomes among smokers who were randomised to receive free samples of snus versus not. Participants (N=1236) were recruited throughout the US and assessed for 1 year following a 6-week naturalistic sampling period, with high retention throughout. Primary outcomes included self-reported quit attempts, floating abstinence (any 7-day period of non-smoking) and 7-day point-prevalence abstinence at 6 months and 12 months. Secondary outcomes were changes in smoking, motivation and confidence to quit and adverse events. No tobacco industry support was provided.

Results: Within snus group, 82% used at least once, and 16% were using regularly at end of sampling period. Compared to control participants, smokers in the snus group were less likely to make any quit attempt (RR=0.83; 95% CI 0.70 to 1.00), and any 24 h quit attempt (RR=0.77; 95% CI 0.63 to 0.95). There were no group differences on any measure of abstinence.

Conclusions: Provision of snus in a naturalistic context resulted in minimal uptake, and as a whole, undermined quit attempts and did not increase smoking abstinence. Results do not support the unguided, free provision of snus among smokers not motivated to quit as a means to facilitate quit attempts.

Trial registration number: NCT01509586, Results.

Keywords: Cessation; Harm Reduction; Non-cigarette tobacco products.

Figure 1

CONSORT Recruitment Flow^{1 1} Percents based on preceding step ² Exclusions are not mutually exclusive. Only top five exclusions presented here; for full details of exclusions, contact first author

Figure 2

Study Retention

Figure 3

Subgroup Comparisons for Snus vs. Control Group: A) Incidence of 24-hr, and B) Floating Abstinence, and Within Snus Group Alone¹: C) Incidence of 24-hr, and D) Floating Abstinence Notes: ¹ Snus Group Only analyses compare samplers, current infrequent users, and current frequent users, each, to never users of snus within the snus group (referent); see text for definitions of snus groups ² Any 7-day period of non-smoking, ever within study ³ Subgroup sample sizes (N) are identical as those shown in panels A and C