Shiffman S, et al. - Researchers compared cigarette consumption in intermittent smokers (ITS) receiving very low-nicotine-content cigarettes (VLNCCs) or identical normal-nicotine-content cigarettes (NNCCs) in this randomized double-blind clinical trial. Among ITS, switching to VLNCCs did not significantly increase abstinence, however, it caused substantial smoking reduction. These results suggest that nicotine-seeking motivates ITS’ smoking.

Methods

• This trial was conducted from June 2015 to July 2017 at a single US site.
• Via media, volunteer ITS not planning to quit were enrolled.
• Two hundred ninety-seven people enrolled, and 238 were randomized in this investigation.
• Analyses were intent-to-treat.
• ITS were randomized to VLNCCs or NNCCs for 10 weeks after a 2-week baseline of smoking their own brand of cigarettes provided for free.
• Researchers evaluated the number of cigarettes per day (CPD) by real-time reporting, timeline follow-back reports, and cigarette butt counts.
• Change in CPD from baseline to weeks 9 to 10 of intervention, adjusting for baseline CPD was the primary outcome.

Results

• The mean (SD) age of the 238 randomized participants was 37.9 (13.8) years; out of 238 study participants, 108 (45%) were men.
• The mean (SD) CPD was 3.1 (2.9) at baseline.
• 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) in intent-to-treat analyses using multiple imputation to address missing data.
• By sex, race/ethnicity, or history of daily smoking, treatment group differences were not materially moderated.
• 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 displayed significant VLNCC impacts among the compliant participants as well.
• The VLNCC and NNCC groups varied 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 in longitudinal analysis of CPD over time with random intercept and slope.
• It was noted that abstinence (intent-to-treat, biochemically verified) in weeks 9 to 10 postrandomization did not vary significantly by treatment group (VLNCC, 10.2% vs NNNC, 5.0%; P=.28).