Switching from cigarettes to IQOS: the relative importance of IQOS-associated reward, reinforcement and abstinence relief.

INTRODUCTION: This study investigated whether IQOS, a heated tobacco product, can fully substitute for combustible cigarettes and the factors that promote substitution. METHODS: Adults who smoked cigarettes daily (N=90; 21-65 years) completed a baseline ad-lib smoking period (days 1-5), two laboratory visits (days 6-7) and a 2-week period where they were instructed to switch from smoking cigarettes to using IQOS 3.0 (days 8-21). Mixed-effect modelling estimated the changes in cigarettes per day (CPD) and the percentage of baseline CPD substituted by HeatSticks during the switch period. Predictors included IQOS-associated subjective reward, relative reinforcing value, craving relief and withdrawal relief. RESULTS: Participants reduced their CPD to about 30% of their baseline smoking rate by the end of the 14-day switch period (p<0001). A lower versus higher reinforcing value of smoking relative to IQOS (RRV; break point <5 vs ≥5) predicted greater reductions in CPD (ß=-1.31 (95% CI -2.35 to -0.27) p=0.013). Initially, IQOS use was 72% of the baseline smoking rate (ß=71.64 (95% CI 42.79 to 100.48) p<0.0001) and climbed by 0.8% per day (ß=0.82 (95% CI 0.01 to 1.64) p=0.05), for an average substitution rate of 83%. The subjective reward of IQOS was the only predictor of a higher substitution rate (ß=4.26 (95% CI 1.03 to 7.50) p=0.01). CONCLUSIONS: IQOS fully substituted for cigarettes in ~20% of people who were not immediately interested in quitting smoking while the remainder significantly reduced their smoking. Positive reinforcing effects of IQOS foster use and the transition away from combustible cigarettes. TRIAL REGISTRATION NUMBER: NCT05076708.

The interacting effects of depression symptoms and sweet flavoring on the rewarding and reinforcing value of cigarillo use among young adults.

Background: Young adults 18-24 years old have the highest prevalence of cigarillo use, exposing young adults to comparable or higher nicotine levels and many of the same toxicants as combustible cigarettes. Identifying individual and product characteristics that increase the potential for persistent use is warranted. We sought to examine the interacting effects of depression symptoms and sweet flavoring on the rewarding and reinforcing value of cigarillo use. Methods: 86 young adults (18-24 years old, 73.3 % male, 38.4 % White, 33.7 % Black, and 27.9 % Other) completed three laboratory visits assessing the subjective rewarding value (exposure paradigm), relative reinforcing value (computerized choice task), and absolute reinforcing value (ad libitum cigarillo smoking session) of sweet-flavored versus non-flavored cigarillos. Depression symptoms were measured with the 20-item Center for Epidemiologic Studies of Depression Scale and treated as a continuous variable. Results: General linear models with the appropriate family link tested differences in depressive symptomology for each outcome. Irrespective of flavor, greater cigarillo subjective reward was reported across increasing depressive symptomology (B=.0.03 [95%CI=0.00, 0.05], p=.017). Across symptom levels, no significant differences were observed in the subjective reward and relative and absolute reinforcing values of sweet-flavored versus non-flavored cigarillos (p's >.05). Conclusions: Young adults with elevated depression find cigarillos more rewarding but not more reinforcing. They are not more vulnerable than young adults with lower symptom levels to sweet cigarillo flavoring. Public health prevention campaigns and tobacco product regulations aimed at preventing the initiation and escalation of young adult cigarillo use may impact young adults broadly.

Effect of sweet flavouring on the rewarding and reinforcing value of cigarillo use among young adults.

INTRODUCTION: Cigarillos dominate the US cigar market, and young adults largely drive use. While young adults prefer flavoured to non-flavoured cigarillos, especially those flavoured to taste like fruit or other sweets, the factors that underlie this preference have received little attention. We sought to determine if key indicators of abuse liability, the rewarding and reinforcing effects, are greater for sweet versus non-flavoured cigarillos. METHODS: Young adults (18-24 years old) completed three laboratory visits assessing the subjective rewarding value (exposure paradigm), relative reinforcing value (computerised choice task) and absolute reinforcing value (ad libitum cigarillo smoking session) of sweet-flavoured versus non-flavoured cigarillos. General linear regression models were fit with the appropriate family link for each outcome measure. RESULTS: Young adults rated sweet-flavoured cigarillos as more rewarding (estimated marginal mean (EMM) =4.52, 95% CI 4.00 to 5.03) than the non-flavoured cigarillo (EMM=3.31, 95% CI 2.80 to 3.83; B=1.20, 95% CI 0.80 to 1.60, p<0.001). The reinforcing value of sweet-flavoured cigarillos, measured by break point, was higher relative to non-flavoured cigarillos (6.34 out of 10), especially among young adults with a preference for flavoured cigarillos (B=1.94, 95% CI 0.71 to 3.18, p=0.003). Young adults took 1.9 times the number of puffs (35.75 vs 19.95) from sweet-flavoured cigarillos compared with non-flavoured cigarillos (Rate Ratio =1.94, 95% CI 1.30 to 2.90, p<0.001). CONCLUSIONS: Sweet flavouring increases the abuse liability of cigarillos among young adults as reflected in greater liking, motivation to use and actual use. Banning sweet flavouring in cigarillos may diminish their use in young adults.Trial registration number CT.gov (NCT05092919).