Citation

Gravely, S., Driezen, P., McClure, E., Hammond, D., Cummings, K.M., Chan, G.C.K., Hyland, A., Borland, R., East, K., Fong, G.T., Schauer, G.L., Quah, A.C.K., Ouimet, J., Smith, D.M. (2022). Differences between adults who smoke cigarettes daily and do and do not co-use cannabis: Findings from the 2020 ITC Four Country Smoking and Vaping Survey. Addictive Behaviours, 135, 107434. doi: 10.1016/j.addbeh.2022.107434.

Abstract

Background: Little is known about population-level differences between adults who exclusively smoke cigarettes and those who smoke cigarettes and also use cannabis (co-consumers). Thus, this study describes differences on sociodemographic, cigarette-dependence, health and behavioral variables, and risk perceptions associated with smoking cannabis.

Methods: This cross-sectional study included 6941 respondents from the 2020 ITC Four Country Smoking and Vaping Survey (US, Canada, Australia, England). Adult daily cigarette smokers were included and categorized as: cigarette-only smokers (never used cannabis/previously used cannabis, but not in the past 12 months, n=4857); occasional co-consumers (cannabis use in the past 12 months, but<weekly use, n=739); or regular co-consumers (use cannabis ≥weekly, n=1345). All outcomes were self-reported. Regression models were conducted on weighted data.

Results: Overall, 19.9% of respondents reported regular cannabis co-use and 10.1% reported occasional co-use. Regular co-use was highest in Canada (27.2%), followed by the US (24.4%), England (12.7%) and Australia (12.3%). Compared to cigarette-only smokers, regular co-consumers were more likely to be male and report chest/breathing problems (p<0.001). All co-consumers were more likely to be younger, have lower income, be experiencing financial stress, reside in Canada, have depressive symptoms, use alcohol more frequently and binge drink, use other tobacco/nicotine products, and perceive smoking cannabis as low health risk and less harmful than smoking cigarettes (all p><0.001). Cigarette dependence measures were similar between co-consumers and cigarette-only smokers (all p≥0.05).

Conclusions: Although there were no differences on cigarette dependence measures between daily cigarette smokers who do and do not use cannabis, there are several other risk factors that may affect tobacco use and abstinence among co-consumers (e.g., greater depression, high-risk alcohol consumption). Thus, tobacco cessation treatment may require multi-pronged strategies to address other health behaviors. Continued surveillance is needed to determine the nature and health implications of co-use considering changing policies, markets, and products.

Citation

Schneller, L., Kasza, K, Hammond, D., Bansal-Travers, M., O’Connor, R.J., Hyland, A. (2022). E-cigarette and tobacco product use among NYS youth before and after a state-wide vaping flavour restriction policy, 2020-2021. Tobacco Control, 31 (Suppl3), s161-s166.

Abstract

Significance: Reducing youth e-cigarette use is a New York State (NYS) public health priority. In May 2020, a state-wide restriction on flavoured e-cigarettes, except tobacco flavour, was passed. This study examines changes in nicotine product use behaviour among youth around the time of the state-wide vaping flavour restriction.

Methods: NYS data from the US International Tobacco Control Policy Evaluation Project Youth Tobacco and E-cigarette Tobacco and Vaping Survey were analysed cross-sectionally from February 2020 (n=955), August 2020 (n=946), February 2021 (n=1030), and August 2021 (n=753). Online surveys were conducted among youth 16–19 years. Weighted descriptive statistics and regression models were used to describe changes in nicotine product use behaviour. Models were adjusted for age, sex, race/ethnicity and perceived family socioeconomic status.

Results: Significant decreases in past 30-day e-cigarette use (20%–11%), cigarette (7%-4%), and dual use of e-cigarettes and cigarettes (5%–2%) were observed over the 2-year period in NYS. Over 95% of vapers still reported using a non-tobacco-flavoured e-cigarette following the restriction, with fruit-flavoured being the most popular at each time point.

Conclusions: Nearly all NYS youth continued to vape flavours that were restricted in NYS. While youth past 30-day vaping prevalence decreased significantly from 2020 to 2021, increased flavour restriction compliance could result in an even greater decrease. Continuous monitoring is important to better understand perceptions, use patterns and access at the individual level, retail level and population level to inform future enforcement and restrictions.

Citation

Freitas Lemos, R., Stein, J.S., Tegge, A.N., Kaplan, B.A., Heckman, B.W., McNeill, A., Cummings, K.M., Fong, G.T., Bickel, W.K. (2022). The Illegal Experimental Tobacco Marketplace II: Effects of vaping product bans - findings from the 2020 International Tobacco Control Project. Tobacco Control, 31(Suppl 3), s214-s222.

Abstract

Significance: Restrictive e-cigarette policies may increase purchases from illegal sources. The Illegal Experimental Tobacco Marketplace (IETM) allows examination of how restrictions impact illegal purchases. We investigated (1) the effect of a vaping ban, total flavour vaping ban and partial flavour vaping ban on the probability of purchasing illegal vaping products among different regulatory environments (USA, Canada and England) and tobacco user types (cigarette smokers, dual users and e-cigarette users); and (2) the relation between ban endorsement and illegal purchases.

Methods: Participants (N=459) from the International Tobacco Control Survey rated their support of bans and chose to purchase from a hypothetical legal experimental tobacco marketplace or IETM under control and the three ban conditions.

Results: In total, 25% of cigarette smokers, 67% of dual users and 79% of e-cigarette users made IETM purchases. Cross-country comparisons depicted dual users from Canada (OR: 19.8), and e-cigarette users from the USA (OR: 12.9) exhibited higher illegal purchases odds than the same user type in England. Within-country comparisons showed e-cigarette and dual users are more likely to purchase from the IETM than cigarette smokers in the most restrictive condition, with the largest effects in e-cigarette users (England-OR: 1722.6, USA-OR: 22725.3, Canada-OR: 6125.0). Increased opposition towards partial or total flavour ban was associated with increased IETM purchasing in the corresponding condition.

Conclusions: Vaping restrictions may shift users' preference to the illegal marketplace in a regulatory environment. Evidence of the IETM generalisability in a geographically dispersed sample enhances its utility in tobacco regulatory science.

Citation

Le Grande, M., Balmford, J., Borland, R., McNeill, A. (2022). Perceived health and capacity to cope with stress in recent ex-smokers: Impact of vaping vs quitting all nicotine. Nicotine and Tobacco Research, [Published online November 1, doi: 10.1093/ntr/ntac252].

Abstract

Background: Little is known about the continued use of nicotine following smoking cessation on perceived well-being in comparison to complete cessation of nicotine use. Aims: To explore aspects of perceived well-being and coping among recent ex-smokers as a function of vaping status.

Methods: Ever-daily smokers in the International Tobacco Control 4 country smoking and vaping surveys in 2016 (W1 N=883) and 2018 (W2 N=1088). Cross-sectional associations and longitudinal samples for those who quit between waves and those quit at W1 who maintained abstinence to W2.

Main outcome measures were: past 30 days depression symptoms, perceived stress, stress management since quitting and change in perceived day-to-day health.

Results: In the cross-sectional analyses vapers were more likely to report both improved stress management (aOR = 1.71, 95% CI 1.23-2.36) and perceived day-to-day health (aOR = 1.65, 95% CI 1.26-2.16) than nicotine abstainers. In the longitudinal analyses, smokers who switched to vaping between waves (n=372) were more likely to report depression symptoms at W2 (aOR = 2.00, 95% CI 1.09-3.65) but reported improved perceived health (aOR = 1.92, 95% CI 1.16-3.20). For the past daily smokers who remained quit between waves (n=382), vapers were more likely to report improved stress management relative to abstainers (RRR =5.05. 95% CI 1.19-21.40). There were no other significant differences between vapers and nicotine abstainers.

Conclusions: There is little evidence to support the view that perceptions of well-being deteriorate in vapers compared to complete nicotine abstainers in the immediate years after smoking cessation.

Implications: This study could find no conclusive evidence that the continued use of nicotine via e-cigarettes was detrimental to health compared to completely stopping nicotine intake altogether. Our results would suggest that continuing to use nicotine may even result in some benefits in the short term such as improved stress management, however further longitudinal studies are required to examine if these effects are restricted to the early post-quitting phase and whether other positive or negative effects on psychosocial health emerge in the future.

Citation

Craig, L., Chung-Hall, J., Meng, G., Fong, G.T. (2022). Calculating the potential environmental impact of a menthol cigarette ban in the United States. Tobacco Control, [Published online October 13, doi: 10.1136/tc-2022-057563].

Infographics: Oct 2022 | Calculating the Potential Environmental Impact of a Menthol Cigarette Ban in the USA

Press Release: Oct 13, 2022 | Proposed menthol ban in U.S. would cut littering by 3.8 billion cigarettes butts annually

Media & Related Documents:

Nov 7, 2022 | The environmental argument for banning menthol cigarettes - Popular Science, Carla Delgado

Nov 7, 2022 | Craig, L.V., & Fong, G.T. (2022). Answers to questions about the impact of a proposed US menthol cigarette ban on reducing cigarette litter. Sent to Carla Delgado, Popular Science.

Citation

Geboers, C., Nagelhout, G.E., de Vries, H., Candel, M.J.J.M., Driezen, P., Mons, U., Andler, R., Fong, G.T., Willemsen, M.C. (2022). Price minimizing behaviours by smokers in Europe (2006-2020): Evidence from the International Tobacco Control Project. European Journal of Public Health, [Published online, doi:10.1093/eurpub/ckac115].

Abstract

Background: Effectiveness of tobacco taxation can be undermined through smokers applying price-minimizing behaviours rather than quitting or reducing consumption. Common price-minimizing strategies are buying cheaper tobacco [discount brands or roll-your-own (RYO) tobacco], bulk buying and cross-border purchasing. This study analyses trends in and factors associated with such behaviours in four European countries from 2006 to 2020.

Methods: Data came from adult smokers participating in the International Tobacco Control (ITC) Surveys conducted between 2006 and 2020 in England (9 waves, n = 768-4149), France (4 waves, n = 1415-1735), Germany (5 waves, n = 513-1515) and the Netherlands (10 waves, n = 1191-2177). Country-specific generalized estimating equation regression models were fit to assess trends in smoking RYO tobacco, discount brands, bulk buying and cross-border purchasing within the European Union.

Results: Buying discount brands or RYO tobacco was the most common strategy in all countries, except France. Except for buying discount brands, estimates of price-minimizing behaviours were highest in France (2019: RYO = 27.2%, discount brands = 17.3%, bulk buying = 34.1%, cross-border purchasing = 34.2%), and lowest in Germany (2018: RYO = 18.6%, discount brands = 43.7%, bulk buying = 8.0%, cross-border purchasing = 9.8%). Direction and magnitude of trends differed by country, and behaviour. Young smokers were less likely to buy in bulk. Low-income and low-education smokers were more likely to purchase RYO tobacco or discount brands. The association with discount brands was not found for French low-income smokers.

Conclusions: Smoking cheaper tobacco is the most prevalent price-minimizing strategy in three countries (England, Germany and Netherlands), and more prevalent among low-income individuals. Harmonizing prices across products and countries would reduce switching to cheaper tobacco.

Citation

Kyriakos, C.N., Driezen, P., Fong, G.T., Chung-Hall, J., Hyland, A., Geboers, C., Quah, A.C.K., Willemsen, M.C., Filippidis, F. (2022). Impact of the European Union’s menthol cigarette ban on smoking cessation outcomes: Longitudinal findings from the 2020-2021 ITC Netherlands Surveys. Tobacco Control, [Published online September 26, doi: 10.1136/tc-2022-057428].

Abstract

Introduction: To reduce the appeal of tobacco, the European Union (EU) banned menthol as a characterising flavour in cigarettes in May 2020. This pre/post-study evaluated the impact of the menthol ban on smoking cessation outcomes among a representative cohort of Dutch smokers.

Methods: Adult (18+ years) smokers were recruited at wave 1 (pre-ban) of the International Tobacco Control Netherlands Surveys (February–March 2020) and followed post-ban at wave 2 (September–November 2020) and wave 3 (June–July 2021) (N=1326 participated in all three waves). Weighted bivariate, logistic regression and generalised estimating equation model analyses were conducted.

Results: Usual menthol use decreased from pre-ban (7.8%) to post-ban (4.0% at wave 2 and 4.4% at wave 3) (p<0.001). Pre-ban menthol smokers had greater odds of making a post-ban quit attempt than non-menthol smokers (66.9% vs 49.6%, adjusted OR (aOR)=1.89, 95% CI: 1.13 to 3.16). Compared with pre-ban non-menthol smokers, a higher proportion of menthol smokers quit by wave 2 (17.8% vs 10.2%, p=0.025) and by wave 3 (26.1% vs 14.1%, p=0.002), although this was not significant after adjusting for other factors. Female pre-ban menthol smokers had greater odds of quitting by wave 3 than female non-menthol smokers (aOR=2.23, 95% CI: 1.10 to 4.51). Most pre-ban menthol smokers (n=99) switched to non-menthol cigarettes (40.0%) or reported that they continued to smoke menthol cigarettes (33.0%) at wave 3.

Conclusions: The EU menthol ban was effective in reducing menthol use and in increasing quit attempts and quitting among pre-ban menthol smokers. Impact could be maximised by closing gaps that allow post-ban menthol cigarette use.

Citation

East, K., Miller, C., Hitchman, S.C., McNeill, A., Tompkins, C. (2022). 'It's not what you'd term normal smoking': A qualitative exploration of language used to describe Heated Tobacco Product (HTP) use and associated user identity. Addiction, [Published online, doi:10.1111/add.16051]

Abstract

Background and aims: Tobacco and nicotine marketplaces have diversified over the past decade, including with the introduction of heated tobacco products (HTPs), such as the brand IQOS. HTPs typically heat tobacco to generate an aerosol that is inhaled. HTP nomenclature is lacking, and how HTP users define and identify themselves remains understudied. Research in this area is important because language can construct identity, and identity can shape behaviour. This study aimed to explore users' language choice when describing IQOS use, and how language relates to user identity.

Methods: Qualitative interviews in London, United Kingdom, with 30 adult current and former IQOS users. Analyses were guided by Iterative Categorization.

Results: Overall, participants expressed confusion and a lack of suitable terminology for how to describe IQOS use. Verbs such as heating and IQOSing were rarely endorsed. Most often, participants reverted to smoking when describing IQOS use and commonly referred to HEETS (tobacco sticks) as cigarettes. Yet the lack of combustion, electronic device, cleaner experience and perceived reductions in health risks led some to frame IQOS as distinct from smoking. Vaping was generally considered inappropriate for describing IQOS use. Participants also manipulated language to suit their circumstances and manage their identity, whereas some IQOS users embraced the terms smoking and smoker, most were eager to distinguish between using IQOS and being labelled a smoker because of the associated negative connotations and to align with perceptions of IQOS use as a better, less harmful behaviour. Instead, when describing their identity, IQOS users more willingly identified as vapers, or ex-smokers, or created new identities (e.g. HEET user).

Conclusions: People who use or have used IQOS (a brand of heated tobacco product) are ambiguous about IQOS terminology. Participants in this study commonly referred to IQOS use as smoking for lack of a more suitable term, but also resisted being labelled as smokers, a choice that may influence smoking cessation. Clear terminology must be used in surveys and by healthcare professionals when asking about cigarette smoking and e-cigarette and heated tobacco product use.

Citation

Subramaniyan, M., Yee, A., Mohd Hairi, F., Kaai, S.C., Amer Nordin, A.S., Danaee, M., Pravinassh, R., Mohamad, A.S., Kamaludin, I.S., Hasan, S.I., Yan, M., Quah, A.C.K., Driezen, P., Fong, G.T. (2022). Are smoking restrictions at public venues and psychosocial beliefs associated with intentions to quit smoking among smokers in Malaysia? Journal of Ethnicity in Substance Abuse, [Published online, doi:10.1080/15332640.2022.2123421].

Abstract

The Malaysian government reinforced smoking restrictions at public venues to protect nonsmokers from secondhand smoke (SHS) exposure. This study examined whether smokers' reports about smoking restrictions and psychosocial beliefs were associated with quit intentions among Malaysian smokers. Data from 1047 cigarette smokers (103 females and 944 males) aged 18 and older from the 2020 International Tobacco Control (ITC) Malaysia Wave 1 Survey were analyzed with bivariate and multivariable logistic regression models. Most Malaysian smokers (85.2%) reported having quit intentions. Smoking was completely restricted in 34.8% of the nighttime venues, 85.3% of air-conditioned (AC) food and beverage (F&B) venues (restaurants, food courts, coffee shops), 87.3% of non-AC F&B, and 69.4% of indoor workplaces. Smokers who visited nighttime entertainment venues where smoking was fully restricted were less likely to have quit intentions. There was no significant association found with quit intentions for smokers who visited AC and non-AC F&B venues and indoor workplaces where smoking was fully restricted. All five psychosocial beliefs assessed, age, and education were positively associated with quit intentions. Malaysian smokers are interested in quitting and psychosocial beliefs were positively associated with quit intentions. There is a need for the Malaysian government to implement and reinforce comprehensive smoking restrictions in all public venues and indoor workplaces to protect nonsmokers from SHS exposure and to encourage smokers to think about quitting, which may influence their quit intentions.

Citation

Sidhu, A., Pednekar, M.S., Fong, G.T., Gupta, P.C., Quah, A.C.K., Unger, J.B., Sussman, S., Wipfli, H.L., Sood, N., Valente, T. (2022). Smoking-related psychosocial beliefs and justifications among smokers in India: Findings from Tobacco Control Policy (TCP) India Surveys. BMC Public Health, 22, 1738

Abstract

Background: Previous research in high-income countries (HICs) has shown that smokers reduce their cognitive dissonance through two types of justifications over time: risk minimizing and functional beliefs. To date, however, the relationship between these justifications and smoking behaviors over time has limited evidence from low- and middle-income countries. This study examines these of justifications and their relation to quitting behavior and intentions among smoking tobacco users in India.

Methods: The data are from the Tobacco Control Policy (TCP) India Survey, a prospective cohort of nationally representative sample of tobacco users. The respondents include smoked tobacco (cigarettes and bidi) users (n = 1112) who participated in both Wave 1 (W1; 2010-2011) and Wave 2 (W2; 2012-2013) surveys. Key measures include questions about psychosocial beliefs such as functional beliefs (e.g., smoking calms you down when you are stressed or upset) and risk-minimizing beliefs (e.g., the medical evidence that smoking is harmful is exaggerated) and quitting behavior and intentions at Wave 2.

Findings: Of the 1112 smokers at W1, 78 (7.0%) had quit and 86 (7.8%) had intentions to quit at W2. Compared to W1, there was a significant increase in functional beliefs at W2 among smokers who transitioned to mixed use (using both smoking and smokeless tobacco) and a significant decrease among those who quit. At W2, smokers who quit held significantly lower levels of functional beliefs, than continuing smokers, and mixed users (M = 2.96, 3.30, and 3.93, respectively, p < .05). In contrast, risk minimizing beliefs did not change significantly between the two waves. Additionally, higher income and lower functional beliefs were significant predictors of quitting behavior at W2.

Conclusion: These results suggest that smokers in India exhibit similar patterns of dissonance reduction as reported in studies from HICs: smokers who quit reduced their smoking justifications in the form of functional beliefs, not risk-minimizing beliefs. Smokers' beliefs change in concordance with their smoking behavior and functional beliefs tend to play a significant role as compared to risk-minimizing beliefs. Tobacco control messaging and interventions can be framed to target these functional beliefs to facilitate quitting

Citation

Kasza, K.A., Hammond, D., Gravely, S., O’Connor, R.J., Meng, G., East, K., Borland, R., Cummings, K.M., Fong, G.T., Hyland, A. (2022). Associations between nicotine vaping uptake and cigarette smoking cessation vary by smokers’ plans to quit: Longitudinal findings from the International Tobacco Control (ITC) Four Country Smoking and Vaping Surveys. Addiction, [Published online, doi:10.1111/add.16050].

Abstract

Background and aims: Most population studies that evaluate the relationship between nicotine vaping and cigarette cessation focus on limited segments of the smoker population. We evaluated vaping uptake and smoking cessation considering differences in smokers' plans to quit.

Design: Longitudinal ITC Four Country Smoking and Vaping Surveys conducted in 2016, 2018, and 2020. Setting: US, Canada, England, Australia.

Participants: Adult daily cigarette smokers who had not vaped in the past 6 months at baseline and had participated in two or more consecutive waves of the ITC Four Country Smoking and Vaping Surveys (n= 2,815).

Measurements: Plans to quit cigarette smoking at baseline (within 6 months, beyond 6 months, not planning to quit) and at follow-up (within 6 months versus not within 6 months); cigarette smoking cessation at follow-up (smoking less than monthly [including complete cessation] versus daily/weekly/monthly smoking); inter-wave vaping uptake (none, only nondaily vaping, any daily vaping). Generalized estimating equations were used to evaluate whether inter-wave vaping uptake was associated with smoking cessation at follow-up, and with planning to quit at follow-up, each stratified by plans to quit smoking at baseline.

Findings: Overall, 12.7% of smokers quit smoking. Smokers not initially planning to quit within 6 months experienced higher odds of smoking cessation when they took up daily vaping (32.4%) versus no vaping (6.8%; adjusted odds ratio [AOR]=8.58, 95% confidence interval [CI]:5.06-14.54). Among smokers planning to quit, smoking cessation rates were similar between those who did and did not take up daily vaping (25.1% vs. 16.8%; AOR=1.91, 95%CI:0.91-4.00), though we could not account for potential use of cessation aids. Daily vaping uptake was associated with planning to quit smoking at follow-up among those initially not planning to quit (AOR=6.32, 95%CI:4.17-9.59).

Conclusions: Uptake of nicotine vaping appears to be strongly associated with cigarette smoking cessation among smokers with no initial plans to quit smoking. Excluding smokers not planning to quit from studies on vaping and smoking cessation may underestimate potential benefit of daily vaping for daily smokers.

Citation

Levy, D.T., Gartner, C., Liber, A.C., Sanchez-Romero, L.M., Yuan, Z., Cummings, K.M., Borland, R. (2022). The Australia Smoking and Vaping Model: The potential impact of removing a ban on nicotine vaping products (NVPs). Nicotine and Tobacco Research, [Published online September 8, doi: 10.1093/ntr/ntac210].

Abstract

Background: We model the potential impact of relaxing current nicotine vaping product (NVP) restrictions on public health in Australia.

Methods: A Restricted NVP Scenario was first developed to project current smoking and vaping rates, where a US smoking model was calibrated to recent Australian trends. To model less restrictive NVP policies, a Permissive NVP Scenario applied rates of switching from smoking to vaping, initiation into NVP and cigarette use, and cessation from smoking and vaping based on US trends. The model measures vaping risk relative to the excess mortality rate of smoking. The public health impacts are measured as the difference between smoking- and vaping-attributable deaths (SVADs) and life years lost (LYLs) in the Restricted and Permissive NVP Scenarios with sensitivity analysis regarding the NVP excess risk and other factors.

Results: Assuming an NVP excess risk of 5% that of smoking, 104.2 thousand SVADs (7.7% reduction) and 2.05 million LYLs (17.3% reduction) are averted during 2017-2080 in the Permissive NVP Scenario compared to the Restricted NVP Scenario. Assuming 40% NVP excess risk, 70 thousand SVADs and 1.2 million LYLs are averted. The impact is sensitive to the rate at which smokers switch to NVPs and quit smoking, and relatively insensitive to the smoking initiation and NVP initiation and cessation rates.

Conclusions: The model suggests the potential for public health gains to be achieved by relaxing NVP access regulations. However, the model would benefit from better information regarding the impact of NVPs on smoking under a relaxation of current restrictions.

Implications: Australia has implemented a strong array of cigarette-oriented policies but has restricted access to nicotine vaping products (NVPs). The Smoking and Vaping Model offers a framework for modeling hypothetical policy scenarios. The Australian model shows the potential for public health gains by maintaining cigarette-oriented policies while relaxing the current restrictive NVP policy. Modeling results under a permissive NVP policy are particularly sensitive to the estimated rates of smoking cessation and switching to vaping, which are not well established and will likely depend on past and future cigarette-oriented policies and the specific NVP policies implemented in Australia.

Citation

Gravely, S., Meng, G., Hammond, D., Hyland, A., Cummings, K.M., Borland, R., Kasza, K., Yong, H.H., Thompson, M.E., Quah, A.C.K., Ouimet, J., Martin, N., O’Connor, R.J., East, K.A., McNeill, A., Boudreau, C., Levy, D.T., Sweanor, D.T., Fong, G.T. (2022). Differences in cigarette smoking quit attempts and cessation between adults who did and did not take up nicotine vaping: Findings from the ITC Four Country Smoking and Vaping Surveys. Addictive Behaviors, 132, 107339.

Abstract

Introduction: There is mixed evidence as to whether nicotine vaping products (NVPs) can help adults who smoke transition away from cigarettes. This study investigated if rates of self-reported attempts to quit smoking and smoking cessation over a period of either 18 or 24 months differed between respondents who initiated nicotine vaping versus those who did not. Outcome comparisons were made between those who: (1) initiated vaping vs. those who did not; (2) initiated daily or non-daily vaping vs. those who did not; and (3) initiated daily or non-daily vaping between surveys and continued to vape at follow-up (daily or non-daily) vs. those who did not initiate vaping.

Methods: This cohort study included 3516 respondents from the ITC Four Country Smoking and Vaping Surveys (Australia, Canada, England, US), recruited at Wave 1 (2016) or 2 (2018) and followed up at Wave 2 (12 months) and/or 3 (2020, 24 months). Adults who smoked daily at baseline and did not have a history of regular vaping were included. Initiation of vaping was defined as beginning to vape at least monthly between surveys. Respondents indicated whether they made an attempt to quit smoking between surveys. Smoking cessation was defined as those who self-reported no longer smoking cigarettes at follow-up.

Results: Relative to those who did not initiate vaping, any daily vaping was associated with a greater likelihood of smokers making a cigarette quit attempt (p<0.001) and quitting smoking (p<0.001). Among smokers who attempted to quit smoking, any daily vaping was associated with a greater likelihood of being abstinent from smoking at follow-up (p=0.001). Respondents who initiated vaping between surveys and were vaping daily at follow up were significantly more likely to have attempted to quit smoking (p<0.001) and to have quit smoking (p<0.001) than those who did not initiate vaping. Respondents who initiated non-daily vaping did not differ significantly from those who did not initiate vaping on any of the outcome measures.

Conclusions: Daily NVP use was associated with increased attempts to quit smoking and abstinence from smoking cigarettes. These findings are consistent with the concept that complete cigarette substitution may be more likely to be achieved when smokers vape nicotine daily.

Citation

Cheng, K.W., Liu, F., Pesko, M.F., Levy, D.T., Fong, G.T., & Cummings, K.M. (2022). Impact of vaping restrictions in public places on smoking and vaping in the US: Evidence using a difference-in-differences approach. Addiction, [Published online August 31, doi:10.1111/add.16039].

Abstract

Aims: To estimate whether and to what extent extending indoor smoking restrictions to include electronic cigarettes (ECs) impact the use of ECs and cigarette smoking among adults in the US. Design: Observational study using a linear probability model and applying a difference-in-differences analysis SETTING: USA PARTICIPANTS: People aged 18 to 54 who lived in US counties where comprehensive indoor smoking laws in bars, restaurants, and private workplaces have been in place prior to 2010 (N = 45,111 for EC use analysis, N = 75,959 for cigarette use analysis). Measurements: Data on cigarette smoking, use of ECs, and place of residence from the Tobacco Use Supplement of the Current Population Survey (TUS-CPS 2010-2011, 2014-2015, and 2018-2019) were combined with the American Nonsmokers' Rights Foundation (ANRF) database of state and local indoor smoking and vaping restriction laws. Findings: Indoor vaping restriction (IVR) coverage was not significantly associated with the likelihood of adult EC use (coefficient estimate = 0.001; 95% confidence interval [CI] =-0.009, 0.013, P-value = 0.783). In addition, IVR coverage was not significantly associated with adult cigarette smoking (coefficient estimate = -0.00; 95% CI = -0.016, 0.015, P-value = 0.954). The non-significant results appeared in different socio-demographic subgroups. Conclusions: Indoor vaping restrictions do not appear to decrease electronic cigarette use among US adults. There is no evidence that indoor vaping restrictions increase or decrease cigarette smoking among US adults.

Citation

Han, M., Seo, D., Kim, Y., Seo, H.G., Cho, S., Lee, S., Lim, S., Kaai, S.C., Quah, A.C.K., Yan, M., Xu, S., Fong, G.T. (2022). Factors associated with quit intentions among adult smokers in South Korea: Findings from the 2020 ITC Korea Survey. International Journal of Environmental Research and Public Health, [Published online August 31, doi: 10.3390/ijerph191710839].

Abstract

Background: South Korea has made substantial progress on tobacco control, but cigarette smoking prevalence is still high. Previous studies were conducted before the use of nicotine vaping products (NVPs) or heated tobacco products (HTPs) became popular. Thus, whether the concurrent use of NVPs or HTPs affects quit intentions among Korean smokers remains a question that needs to be explored. This study aims to identify predictors of quit intentions among cigarette-only smokers and concurrent users of cigarettes and NVPs or HTPs.

Methods: Data were from the 2020 International Tobacco Control Korea Survey. Included in the analysis were 3778 adult cigarette smokers: 1900 at-least-weekly exclusive smokers and 1878 at-least-weekly concurrent smokers and HTP or NVP users. Bivariate and multivariable logistic regression analyses were conducted.

Results: Quit intentions were reported by 66.4% of respondents. Factors significantly associated with quit intentions included younger age, having a spouse/partner, lower nicotine dependence, reporting a past quit attempt, regretting starting smoking, believing that smoking had damaged health, worrying that smoking will damage future health, and perceiving health benefits of quitting. Current use of NVPs or HTPs was not significantly associated with quit intentions.

Conclusions: This study contributes the following to current literature: intrinsic health-related beliefs were more important than societal norms in shaping quit intentions. These findings should be considered in shaping future smoking cessation policies, such as reinforcing education programs that emphasize the benefits of quitting for personal health reasons, lowering nicotine dependence, and encouraging multiple quit attempts and successful quitting.

Citation

Hammond, D., Reid, J., Rynard, V.L., O’Connor, R.J., Goniewicz, M.L., McNeill, A., Piper, M.E., Bansal-Travers, M. (2022). Indicators of dependence and efforts to quit vaping and smoking among youth in Canada, England, and the United States. Tobacco Control, 31, e25-e34. doi: 10.1136/tobaccocontrol-2020-056269

Abstract

Objective: The current study examined indicators of dependence among youth cigarette smokers and e-cigarette users in Canada, England and the USA, including changes between 2017 and 2019.

Methods: Data are from repeated cross-sectional online surveys conducted in 2017, 2018 and 2019 with national samples of youth aged 16-19 years, in Canada (n=12 018), England (n=11 362) and the USA (n=12 110). Measures included perceived addiction to cigarettes/e-cigarettes, frequency of experiencing strong urges to smoke/use an e-cigarette, plans to quit smoking/using e-cigarettes and past attempts to quit. Logistic regression models were fitted to examine differences between countries and changes over time.

Results: The proportion of ever-users who vaped frequently was significantly higher in 2019 compared with 2017 for all outcomes in each country. Between 2017 and 2019, the proportion of past 30-day vapers reporting strong urges to vape on most days or more often increased in each country (Canada: 35.3%, adjusted OR (AOR) 1.69, 95% CI 1.20 to 2.38; England: 32.8%, AOR 1.55, 1.08 to 2.23; USA: 46.1%, AOR 1.88, 1.41 to 2.50), along with perceptions of being 'a little' or 'very addicted' to e-cigarettes (Canada: 48.3%, AOR 1.99, 1.44 to 2.75; England: 40.1%, AOR 1.44, 1.03 to 2.01; USA: 53.1%, AOR 1.99, 1.50 to 2.63). Indicators of dependence among smokers were consistently greater than e-cigarette users, although differences had narrowed by 2019, particularly in Canada and the USA.

Conclusions: Prevalence of dependence symptoms among young e-cigarette users increased between 2017 and 2019, more so in Canada and the USA compared with England. Dependence symptom prevalence was lower for e-cigarettes than smoking; however, the gap has narrowed over time.

Citation

Li, L., Borland, R., Yong, H.H., Gravley, S., Fong, G.T., Cummings, K.M., East, K.A., Le Grande, M. (2022). Experienced effects on well-being following smoking cessation: Findings from the 2020 ITC Four Country Smoking and Vaping Survey. International Journal of Environmental Research and Public Health, 19(16), 10037. doi: 10.3390/ijerph191610037

Abstract

Background and Aims: There has been limited research addressing changes in subjective well-being as a result of quitting smoking. This paper examines recent ex-smokers’ well-being related experiences overall and as a function of (1) duration of cessation and (2) continued nicotine use from vaping.

Methods: A sample of 1379 ever-daily smoking ex-smokers (quit for up to 5 years) from the 2020 ITC Four Country Smoking and Vaping Survey (Australia, Canada, the UK, and the US), of which 27.1% currently vaped daily. Well-being measures were perceived changes post-quitting in emotion coping (stress and negative emotions), enjoyment of life, and day-to-day functioning. We also assessed the level of persisting worry about past smoking leading to future health problems.

Results: Overall, among those answering all four well-being measures, 51.8% of the ex-smokers reported positive effects and no negatives, but 27.3% reported at least one negative effect, with the remainder reporting no change in any measure. Positive effects were greater among those who had quit more than 1 year prior. The largest improvement (56.3%) was for daily functioning, which showed improvement over time since having quit. Current daily vapers reported similar well-being as those not vaping; however, fewer daily vapers reported worsening ability to cope with stress (10.2% vs. 20.7%). Overall, 84% reported being worried about future negative health effects of smoking, with no clear differences by quitting duration or vaping status.

Conclusions: Most ex-smokers reported changes in their well-being since quitting, with more reporting improvements than declines. Well-being improved with duration of time since quitting, but did not appear to be influenced by daily vaping use, but stress coping may be better among vapers. Persisting worries about possible future health effects from smoking may be reducing the experienced benefits of quitting smoking for some.

Citation

East, K., Reid, J., Hitchman, S.C., Hammond, D. (2022). Purchasing and sourcing of e-cigarettes among youth in Scotland and England following Scotland's implementation of an e-cigarette retail register and prohibition of e-cigarette sales to under-18s. Qeios, [Published online, doi:10.32388/1JZU74].

Abstract

Background. Scotland implemented new e-cigarette regulations in April 2017 prohibiting sales to under18s, requiring age verification, and requiring retailer registration. This study examined purchasing and sourcing of e-cigarettes among minors aged 16-17, and youth aged 18-19, in the short- (4 months) and longer-term (16 months) after regulations were implemented, compared with England.

Methods. Data were from the July/August 2017 and August/September 2018 cross-sectional online ITC Youth Tobacco and Vaping Surveys of 16- to 19-year-olds in Scotland (n2017/2018=434/377) and England (n2017/2018=3,791/3,743). Logistic regressions were used to examine differences in past-12- month purchasing, past-12-month sale refusal, and past-30-day sourcing of e-cigarettes between 2017 and 2018, by country and age group.

Results. Among vapers aged 16-17 in Scotland, from 4 to 16 months post-regulations, e-cigarette purchasing increased from 21% to 50% and sale refusal increased from 14% to 16%, but these changes were not significant and did not differ from changes observed in 18-19-year-olds or England (p>.05). Purchasing and sale refusal were most common in vape shops. Purchasing from a vape shop increased among vapers aged 16-17 in Scotland from 4 to 16 months post-regulations (17% to 85%, p=.003) but not among 18-19-year-olds or in England (p>.05). Among past-30-day vapers, social sources were most common.

Conclusions. Youth vapers in Scotland showed no significant changes in overall purchasing, sale refusal, or sourcing of e-cigarettes, from 4 to 16 months post-regulations, and changes did not differ by age group or from England. Findings suggest low compliance with age-of-sale regulations in Scotland and England.

Citation

Li, L., Borland, R., Cummings, K.M., Fong, G.T., Hyland, A., Le Grande, M., McNeill, A. (2022). Non-cigarette combustible tobacco use and its associations with subsequent cessation of smoking among daily cigarette smokers: Findings from the International Tobacco Control Four Country Smoking and Vaping Surveys (2016-2020). Addiction, [Published online August 8, doi: 10.1111/add.16023

Abstract

Aims: To examine whether poly-use of cigarettes and other smoked products (poly-smoking) is predictive of quit attempts and quit success.

Design: A prospective multi-country cohort design.

Setting: Australia, Canada, England and the US.

Participants: 3983 adult daily cigarette smokers were surveyed in 2016 (Wave 1 of data collection) and were recontacted in 2018 (Wave 2) (i.e., Wave 1–Wave 2 cohort) in the International Tobacco Control Four Country Smoking and Vaping (ITC 4CV) Surveys; and 3736 smokers were surveyed in 2018 and recontacted in 2020 (Wave 3) (i.e., Wave 2–Wave 3 cohort).

Measurements: Participants were asked about their cigarette smoking and use of cigars, cigarillos, pipes, and waterpipes. Outcomes were quit attempts between two survey waves and success, defined as having quit smoking all the combustible tobacco at the subsequent survey for 1 month or more.

Findings: Levels of poly-smoking were 12.7% in the Wave 1–Wave 2 cohort and 10.5% for the Wave 2–Wave 3 cohort. Compared with cigarette-only smokers, poly-smokers were more likely to attempt between Waves 1 and 2 (54.9% vs. 42.7%, adjusted odds ratio (aOR)=1.37, 95% confidence interval [CI] 1.08-1.74, p<0.01), but not between Waves 2 and 3 (43.8% vs. 40.1%, aOR=0.94, 95%CI 0.72-1.22). Poly-smoking predicted reduced likelihood of success in both cohorts among attempters and the overall samples. Between Waves 2 and 3 there were significantly more transitions to non-daily smoking among the poly-smokers (12.4% vs. 5.3%, 2=40.4, p<0.001).

Conclusions: There is a consistent association between poly-smoking (use of cigarettes along with other smoked products) and reduced quit success for combustible tobacco, but it is likely due to increased likelihood of transitioning to non-daily use rather than complete cessation.

Citation

Yong, H.H., Gravely, S., Borland, R., Gartner, C., Cummings, K.M., East, K., Tagliaferri, S., Elton-Marshall, T., Hyland, A., Bansal-Travers, M., Fong, G.T. (2022). Do smokers’ perceptions of the harmfulness of nicotine replacement therapy and nicotine vaping products as compared to cigarettes influence their use as an aid for smoking cessation? Findings from the ITC Four Country Smoking and Vaping Surveys. Nicotine & Tobacco Research, 24(9), 1413-1421. doi: 10.1093/ntr/ntac087.

Abstract

Aim: This study examined whether smokers' harm perceptions of nicotine replacement therapy (NRT) and nicotine vaping products (NVPs) relative to cigarettes predicted their subsequent use as smoking cessation aids during their last quit attempt (LQA).

Methods: We analyzed data from 1,315 current daily smokers (10+ cigarettes per day) who were recruited at Wave 1 (2016), and who reported making a quit attempt by Wave 2 (2018) of the International Tobacco Control Four Country Smoking and Vaping Surveys in Australia, Canada, England, and the US. We used multinomial logistic regression models to examine prospective associations between harm perceptions of a) NRT and b) NVPs and their use at LQA, controlling for socio-demographic and other potential confounders.

Results: Smokers who perceive that a) NRT and b) NVPs are much less harmful than cigarettes were more likely to subsequently use the respective product as an aid than using no aid or other aids during LQA (adjusted relative risk ratio [aRRR]=3.79, 95%CI=2.16-6.66; and aRRR=2.11, 95%CI=1.29-3.45, respectively) compared to smokers who perceive these products as equally or more harmful. Additionally, those who perceive NVPs as much less harmful than cigarettes were less likely to use NRT as a quit aid (aRRR=0.34, 95%CI=0.20-0.60). No country variations for these associations were found.

Conclusion: This study found that smokers' perceptions of the harmfulness of a) NRT and b) NVPs relative to cigarettes predicted the respective product use when trying to quit smoking. Corrective education targeting misperceptions of nicotine products' relative harmfulness may facilitate their use for smoking cessation.

Implications: What this study adds: Nicotine replacement therapy and nicotine vaping products are two commonly used smoking cessation aids. This study demonstrates that misperceptions of the harms of nicotine products relative to cigarettes influence their use for smoking cessation. Believing that nicotine vaping products are much less harmful than cigarette smoking may lead some smokers to prefer these products over nicotine replacement therapy to aid smoking cessation. Education targeting misperceptions of nicotine products' harmfulness relative to cigarettes may enable smokers to make informed choices about which are appropriate to aid smoking cessation.

Citation

Felicione, N., Fix, B., McNeill, A., Cummings, K.M., Goniewicz, M.L., Hammond, D., Borland, R., Heckman, B.W., Bansal-Travers, M., Gravely, S., Hitchman, S.C., Levy, D.T., Fong, G.T., O’Connor, R.J. (2022). Characteristics and changes over time of nicotine vaping products used by participants in the 2016 and 2018 ITC Four Country Smoking and Vaping Surveys. Tobacco Control, 31(e1), e66-e73. doi: 10.1136/tobaccocontrol-2020-056239

Abstract

Objectives: Regulation of nicotine vaping products (NVPs) varies between countries, impacting the availability and use of these products. This study updated the analyses of O'Connor et al on types of NVPs used and examined changes in NVP features used over 18 months in four countries with differing regulatory environments.

Design: Data are from 4,734 adult current vapers in Australia, Canada, England, and the USA from Waves 1 (2016) and 2 (2018) of the International Tobacco Control Four Country Smoking and Vaping Survey. NVP characteristics included device description, adjustable voltage, nicotine content and tank size. Longitudinal analyses (n=1,058) assessed movement towards or away from more complex/modifiable NVPs. A logistic regression was used to examine factors associated with changes in device description from 2016 to 2018.

Results: Like 2016, box-tanks were the most popular NVP (37.3%) in all four countries in 2018. Over 80% of vapers continued using the same NVP and nicotine content between waves, though movement tended towards more complex/modifiable devices (14.4% of vapers). Box-tank users, exclusive daily vapers and older vapers were most likely to continue using the same device description. Certain NVPs and features differed by country, such as higher nicotine contents in the USA (11.5% use 21+ mg/mL) and greater device stability over time in Australia (90.8% stability).

Conclusions: Most vapers continued using the same vaping device and features over 18 months. Differences in NVP types and features were observed between countries, suggesting that differing NVP regulations affect consumer choices regarding the type of vaping device to use.

Citation

Freitas Lemos, R., Tegge, A.N., Craft, W.H., Tomlinson, D.C., Stein, J., Bickel, W.K. (2022). Understanding data quality: Instructional comprehension as a practical metric in crowdsourced investigations of behavioural economic cigarette demand. Experimental and Clinical Psychopharmacology, 30(4),415-423.

Abstract

Crowdsourcing platforms allow researchers to quickly recruit and collect behavioral economic measures in substance-using populations, such as cigarette smokers. Despite the broad utility and flexibility, data quality issues have been an object of concern. In two separate studies recruiting cigarette smokers, we sought to investigate the association between a practical quality control measure (accuracy on an instruction quiz), on internal consistency of number of cigarettes smoked per day and purchasing patterns of tobacco products in an experimental tobacco marketplace (ETM; Study 1), and in a cigarette purchase task (CPT; Study 2). Participants (N = 312 in Study 1; N = 119 in Study 2) were recruited from Amazon mechanical turk. Both studies included task instructions, a quiz, a purchase task, cigarette usage and dependence questions, and demographics. The results show that participants who answered all instruction items correctly: (a) reported the number of cigarettes per day more consistently (partial η2 = 0.11, p < .001, Study 1; partial η2 = 0.09, p = .016, Study 2), (b) demonstrated increased model fit among the cigarette demand curves (partial η2 = 0.23, p < .001, Study 1; partial η2 = 0.08, p = .002, Study 2), and purchased tobacco products in the ETM more consistently with their current usage. We conclude that instruction quizzes before purchase tasks may be useful for researchers evaluating demand data. Instruction quizzes with multiple items may allow researchers to choose the level of data quality appropriate for their studies.

Citation

Cho, Y., Thrasher, J.F., Gravely, S., Alberg, A.J., Borland, R., Yong, H.H., Cummings, K.M., Hitchman, S.C., Fong, G.T. (2022). Adult smokers’ discussions about vaping with health professionals and subsequent behavior change: a cohort study. Addiction, 117(11), 2933-2942. doi: 10.1111/add.15994.

Abstract

Aims: To measure the prevalence and changes in smokers' discussions with health professionals (HPs) about nicotine vaping products (NVPs) and HPs' recommendations about NVPs between 2016 and 2020, and their associations with tobacco product use transitions.

Design: Cohort study using multinomial logistic regression analyses on data from Waves 1 (2016), 2 (2018), and 3 (2020) from the International Tobacco Control Four Country Smoking and Vaping Surveys.

Setting: Four countries with varying NVP regulatory environments: 'most restrictive' (Australia), 'somewhat restrictive' (Canada), and 'less restrictive' (England and the US).

Participants: Adult exclusive daily smokers who did not report NVP use at the time of their baseline survey and had visited a HP in the last 12-24 months. Prevalence data came from 4,125, 4,503, and 4,277 respondents respectively for each year. Longitudinal data were from 4,859 respondents who participated in at least two consecutive surveys.

Measurements: (1) Prevalence of self-reported discussions with HPs and recommendations from HPs about NVPs and (2) longitudinal transitions from smoking to vaping (either exclusively or concurrently with smoking) and quitting (regardless of NVP uptake).

Findings: The prevalence of NVP discussions was low across countries with varying regulatory environments and study waves (range=1.4%-6.2%). In 2020, a low percentage of smokers who discussed NVPs with a HP reported that their HPs recommended they use NVPs in the US (14.7%), Australia (20.2%), Canada (25.7%), with a higher percentage in England (55.7%) where clinical guidelines for smoking cessation include NVPs. Compared with 12.0% of smokers who reported no discussion, 37.0% of those whose HPs recommended NVPs transitioned to vaping at follow-up. Transition to quitting was 9.6% with HPs' recommendation of NVPs versus 13.5% without discussion, a non-significant difference.

Conclusions: In Australia, Canada, England, and the United States between 2016 and 2020, health professionals' discussions with smokers about nicotine vaping products (NVPs) were infrequent. NVP discussions were associated with NVP uptake, but not with quitting smoking.

Citation

Chung-Hall, J., Fong, G.T., Meng, G., Cummings, K.M., Hyland, A., O’Connor, R.J., Quah, A.C.K., Craig, L. (2022). Evaluating the impact of menthol cigarette bans on cessation and smoking behaviours in Canada: Longitudinal findings from the Canadian arm of the 2016-2018 ITC 4 Country Smoking and Vaping Surveys. Tobacco Control, 31(4), 556-563. doi: 10.1136/tobaccocontrol-2020-056259.

Abstract

Objective To evaluate the impact of menthol cigarette bans in seven Canadian provinces between 2016 and 2018.

Methods Longitudinal data from the Canadian arm of the 2016 and 2018 ITC Four Country Smoking and Vaping Survey. 1098 non-menthol and 138 menthol smokers were surveyed pre-menthol and post-menthol cigarette bans. Multivariate logistic regression models examined associations between pre-post ban changes in smoking behaviour, including differences between menthol and non-menthol smokers in quit attempts and quitting.

Results At follow-up, 59.1% of pre-ban menthol smokers switched to non-menthol cigarettes; 21.5% quit smoking and 19.5% still smoked menthols, primarily purchased from First Nations reserves. Menthol smokers were more likely than non-menthol smokers to make a quit attempt (adjusted OR (aOR)=1.61, 95% CI 1.03 to 2.51), and to remain quit (aOR=2.30, 95% CI 1.06 to 5.01). Menthol smokers did not differ significantly from non-menthol smokers in quit success (aOR=1.72, 95% CI 0.98 to 3.01); however, daily menthol smokers were more likely than daily non-menthol smokers to quit (aOR=2.21, 95% CI 1.15 to 4.24), and daily menthol smokers who quit before the ban were more likely than daily non-menthol smokers to remain quit (aOR=2.81, 95% CI 1.15 to 6.85).

Conclusions Although menthol smokers were most likely to switch to non-menthol cigarettes, the menthol ban was also significantly associated with higher rates of quit attempts and quit success among menthol smokers compared with non-menthol smokers, and may have helped to prevent relapse among menthol smokers who had quit smoking before the ban. Results confirm and extend evaluation of Ontario’s menthol ban across provinces covering 83% of the Canadian population.

Related reports:

Apr 28, 2021 | Impact of Canada's Menthol Ban on Quitting: Implications for the United States | English

Apr 25, 2021 | ITC Evaluation of Canada's Menthol Ban: Infographic | English

Apr 5, 2021 | Canada's Menthol Ban Did NOT Increase Illicit Purchasing | English

Apr 5, 2021 | Impact of Canada's Menthol Ban on Quitting: Implications for California | English

Citation

Zhao, Y., Yong, H., Borland, R., Cummings, K.M., Thrasher, J., Hitchman, S.C., Bansal-Travers, M., Fong, G.T. (2022). Do numbers of smoking friends and changes over time predict smoking relapse? Findings from the International Tobacco Control Four-Country Survey. Journal of Substance Abuse Treatment, 138, 108763.

Abstract

Background: Past research indicates that smokers with a large number of smoking friends within their social network are less interested in quitting, less likely to attempt to quit, and less likely to successfully quit. The extent to which a pro-smoking social network may increase relapse risk among ex-smokers is unclear. This study investigated among ex-smokers whether the number of close friends who smoke and changes in this number influence relapse risk.

Methods: The study was a prospective cohort study of 551 adults who participated in the Australian and UK arms of the International Tobacco Control (ITC) project and were ex-smokers at wave 9 (2013) and followed up to wave 10 (2014). Logistic models regressed smoking relapse at follow-up on the baseline number of their five closest friends who smoked and changes in this number over time.

Results: Ex-smokers who reported having 4 or 5 smokers among their five closest friends were more likely to relapse than those who had no smokers among their five closest friends (adjusted odds ratio [AOR] = 4.86, 95% confidence interval [CI] = 1.48-15.99, p = .009). Ex-smokers who gained smoking friends over time, but not those who lost smoking friends, were also more likely to relapse compared to those with the same number of smoking friends over time (AOR = 4.52, 95% CI = 2.15-9.52, p < .001; AOR = 1.08, 95% CI = 0.49-2.36, p = .848, respectively).

Conclusions: This study demonstrated that relapse risk was elevated among ex-smokers who had more smokers among their close friends and also among those where the number of smokers in their social network increased over time.