Very-low-nicotine-content cigarettes and dependence among non-daily smokers.

BACKGROUND: The US Food and Drug Administration is considering reductions in the nicotine content of cigarettes to reduce smoking and tobacco dependence. A randomized study showed that even non-daily, intermittent smokers (ITS) reduced their cigarette consumption when switched to very-low-nicotine-content cigarettes (VLNCCs). This paper assesses whether switching ITS to VLNCCs results in decreased dependence and whether subsequent cigarette consumption is mediated by decreased dependence. METHODS: ITS randomized to VLNCCs (n = 118) or normal nicotine content cigarettes (n = 120) completed multiple measures of dependence (Fagerstrom Test of Nicotine Dependence [FTND], Nicotine Dependence Syndrome Scale [NDSS], Wisconsin Inventory of Smoking Dependence Motives [WISDM], and Hooked on Nicotine Checklist [HONC]) at Baseline and 2, 6, and 10 weeks after randomization. A principal component factor score captured common variance among these measures (except FTND). Cigarettes per day (CPD) was assessed by three convergent methods. RESULTS: Switching ITS to VLNCCs reduced dependence on all measures except the WISDM Secondary Dependence Motives and HONC. Except for the effects on the factor score, these effects of VLNCCs could be accounted for by contemporaneous CPD. Week-2 dependence measures did not prospectively predict weeks 3-4 CPD, once antecedent dependence and CPD were accounted for. "Cheating" among participants who appear to have smoked conventional cigarettes did not affect the findings. DISCUSSION: Among ITS, switching to VLNCCs results in reduced tobacco dependence. However, the reductions in dependence appear to be secondary to effects on cigarette consumption, and do not appear to be an independent predictor or cause of reduced cigarette consumption.

Do non-daily smokers compensate for reduced cigarette consumption when smoking very-low-nicotine-content cigarettes?

RATIONALE: The Food and Drug Administration is considering severely restricting the nicotine in cigarettes, to reduce smoking. A study showed that non-daily, intermittent smokers (ITS) randomized to very-low-nicotine-content cigarettes (VLNCCs) reduced their cigarette consumption. OBJECTIVES: To assess whether increased smoking intensity of VLNCCs compensated for some of the reduced cigarette consumption. METHODS: After a 2-week baseline smoking their own-brand cigarettes, 118 ITS were randomized to VLNCCs (~ 1 mg nicotine/g tobacco), and 120 to normal-nicotine-content cigarettes (NNCCs; ~ 16 mg/g) for 10 weeks. Laboratory measures of smoking intensity-total puff volume and carbon monoxide (CO) boost-assessed single cigarettes smoked in up to three laboratory topography sessions. Field measures assessed returned cigarette butts, averaged over up to five 2-week intervals: the mass of tobacco burned (computed from residual mass of butts) and the intensity of smoking (by scanning of returned filters). Analysis was by mixed model random effects models using baseline values as covariates. RESULTS: ITS in the VLNCC group puffed less smoke in topography sessions (-38.50 mL [-75.21, -1.78]; p < 0.04), but showed no difference in CO boost. Participants in the VLNCC group burned 0.02 [0.04, 0.002] grams less tobacco per cigarette (p < 0.03). Analysis of filters showed their smoking intensity declined over time, compared to NNCC participants (p < 0.04). "Cheating" by smoking normal cigarettes did not moderate these effects. CONCLUSIONS: ITS did not increase their smoking intensity when switched to VLNCCs; indeed, their smoking intensity decreased. Reductions in cigarette consumption seen when ITS are switched to VLNCCs were not compensated by increased smoking intensity.

Nondaily Smokers' Changes in Cigarette Consumption With Very Low-Nicotine-Content Cigarettes: A Randomized Double-blind Clinical Trial.

Importance: The US Food and Drug Administration is considering limiting cigarettes to very low nicotine levels. Cigarette consumption of nondaily intermittent smokers (ITS), who compose one-third of US adult smokers, could feasibly increase or could be unaffected if their smoking is not motivated by nicotine seeking. Objective: To compare cigarette consumption in ITS receiving very low-nicotine-content cigarettes (VLNCCs) or identical normal-nicotine-content cigarettes (NNCCs). Design, Setting, and Participants: This randomized double-blind clinical trial was conducted from June 2015 to July 2017 at a single US site. Volunteer ITS not planning to quit were recruited via media. Overall, 297 individuals enrolled, and 238 were randomized. Analyses were intent-to-treat. Interventions: After a 2-week baseline of smoking their own brand of cigarettes provided gratis, ITS were randomized to VLNCCs or NNCCs for 10 weeks. Main Outcomes and Measures: The number of cigarettes per day (CPD) was assessed by real-time reporting, timeline follow-back reports, and cigarette butt counts. The primary outcome was change in CPD from baseline to weeks 9 to 10 of intervention, adjusting for baseline CPD. Results: The mean (SD) age of the 238 randomized participants was 37.9 (13.8) years. Of 238 participants, 108 (45%) were men. At baseline, the mean (SD) CPD was 3.1 (2.9). In intent-to-treat analyses using multiple imputation to address missing data, the VLNCC group had a mean decrease of 1.6 CPD (95% CI, 1.1-2.0; 51% of baseline) vs 0.05 decrease with NNCCs (95% CI, -0.5 to 0.4; 2% of baseline). Treatment group differences were not materially moderated by sex, race/ethnicity, or history of daily smoking. Cheating with conventional cigarettes, inferred from cotinine assays, was more common in the VLNCC group (OR, 2.95; 95% CI, 1.54-5.66), but sensitivity analyses showed significant VLNCC effects among the compliant participants as well. In longitudinal analysis of CPD over time with random intercept and slope, the VLNCC and NNCC groups differed significantly in both linear (-0.15; 95% CI, -0.22 to -0.08; P < .001) and quadratic (0.0026; 95% CI, 0.0010-0.0042; P = .002) trends: CPD dropped by 43.8% in the VLNCC group over 4 weeks, then leveled off thereafter. Abstinence (intent-to-treat, biochemically verified) in weeks 9 to 10 postrandomization did not differ significantly by treatment group (VLNCC, 10.2% vs NNNC, 5.0%; P = .28). Conclusions and Relevance: Switching to VLNCCs caused substantial smoking reduction among ITS but did not significantly increase abstinence. Response to a VLNCC intervention suggests that nicotine-seeking motivates ITS' smoking. Trial Registration: ClinicalTrials.gov Identifier: NCT02228824.