Abstract

Introduction: To date, no studies have explored how different regulatory environments may influence the effectiveness of ECs as a smoking cessation aid.

Objective: This study compares the real-world effectiveness of adult smokers using ECs for quitting compared with quitting unassisted or quitting with NRT and/or prescription medications in two countries with restrictive policies towards ECs (i.e., Canada and Australia) versus two countries with less restrictive policies (i.e., US and UK).

Methods: Data were drawn from the International Tobacco Control Four Country surveys, from the US and Canada (2 waves, n=318 and 380, respectively), the UK (3 waves, n=439) and Australia (4 waves, n=662), collected 2010-2014. Smokers at baseline wave who reported making a quit attempt at follow-up were included. The primary outcome was self-reported abstinence for at least 30 days regardless of smoking status at follow-up assessment. Data across waves were combined and analysed using generalised estimating equations.

Results: Compared to unassisted quitting (i.e. no medications or ECs), smokers who used ECs for quitting from countries with less restrictive EC policy environments were more likely (OR=1.95, 95%CI=1.19-3.20, p<0.01), whereas smokers who used ECs for quitting from countries with more restrictive EC policies were less likely (OR=0.36, 95%CI=0.18-0.72, p<0.01), to report sustained abstinence for at least 30 days.

Conclusion: Use of ECs in the real world during a quit attempt appears only effective for sustaining smoking abstinence in a less restrictive EC environment suggesting that the benefits of ECs for smoking cessation are likely highly dependent on the regulatory environment.

Implications: What this study adds: This is the first study to examine the impact of regulatory environment for electronic cigarettes (ECs) on their real-world effectiveness for smoking cessation. This study shows that in a less restrictive EC regulatory environment, use of ECs during a quit attempt facilitates, but in a more restrictive environment, it inhibits, short-term sustained abstinence. The findings underscore the need for careful consideration on how best to regulate this emerging product so that EC benefits for smoking cessation are maximised and its risks to public health are minimised.

Citation

Kasza, K.A., Hyland, A., Borland, R., McNeill, A., Fong, G.T., Carpenter, M.J., Partos, T.R., Cummings, K.M. (2017). Cross-country comparison of smokers’ reasons for thinking about quitting over time: Findings from the International Tobacco Control Four Country Survey (ITC-4C), 2002-2015. Tobacco Control, 26(6), 641-648.

Abstract

Objective: To explore between-country differences and within-country trends over time in smokers' reasons for thinking about quitting and the relationship between reasons and making a quit attempt.

Methods: Participants were nationally representative samples of adult smokers from the UK (N=4717), Canada (N=4884), the USA (N=6703) and Australia (N=4482), surveyed as part of the International Tobacco Control Four Country Survey between 2002 and 2015. Generalised estimating equations were used to evaluate differences among countries in smokers' reasons for thinking about quitting and their association with making a quit attempt at follow-up wave.

Results: Smokers' concern for personal health was consistently the most frequently endorsed reason for thinking about quitting in each country and across waves, and was most strongly associated with making a quit attempt. UK smokers were less likely than their counterparts to endorse health concerns, but were more likely to endorse medication and quitline availability reasons. Canadian smokers endorsed the most reasons, and smokers in the USA and Australia increased in number of reasons endorsed over the course of the study period. Endorsement of health warnings, and perhaps price, appears to peak in the year or so after the change is introduced, whereas other responses were not immediately linked to policy changes.

Conclusions: Differences in reasons for thinking about quitting exist among smokers in countries with different histories of tobacco control policies. Health concern is consistently the most common reason for quitting and the strongest predictor of future attempts.

Citation

Kasza, K.A., Hyland, A., Cummings, K.M., Carpenter, M.J., Fong, G.T., Borland, R., McNeill, A. (2017). A cross-country comparison of smokers’ reasons for thinking about quitting over time: Findings from the International Tobacco Control Four Country Survey (ITC-4C), 2002-2015. Tobacco Control, 26(6), 641-48.

Abstract

Objective: To explore between-country differences and within-country trends over time in smokers' reasons for thinking about quitting and the relationship between reasons and making a quit attempt.

Methods: Participants were nationally representative samples of adult smokers from the UK (N=4717), Canada (N=4884), the USA (N=6703) and Australia (N=4482), surveyed as part of the International Tobacco Control Four Country Survey between 2002 and 2015. Generalised estimating equations were used to evaluate differences among countries in smokers' reasons for thinking about quitting and their association with making a quit attempt at follow-up wave.

Results: Smokers' concern for personal health was consistently the most frequently endorsed reason for thinking about quitting in each country and across waves, and was most strongly associated with making a quit attempt. UK smokers were less likely than their counterparts to endorse health concerns, but were more likely to endorse medication and quitline availability reasons. Canadian smokers endorsed the most reasons, and smokers in the USA and Australia increased in number of reasons endorsed over the course of the study period. Endorsement of health warnings, and perhaps price, appears to peak in the year or so after the change is introduced, whereas other responses were not immediately linked to policy changes.

Conclusions: Differences in reasons for thinking about quitting exist among smokers in countries with different histories of tobacco control policies. Health concern is consistently the most common reason for quitting and the strongest predictor of future attempts.

Citation

Levy, D., Borland, R., Lindblom, E., Goniewicz, M., Meza, R., Holford, T.R., Yuan, Z., Luo, Y., O’Connor, R.J., Niaura, R., Abrams, D.B. (2018). Potential deaths averted in USA by replacing cigarettes with e-cigarettes. Tobacco Control, 27(1), 18-25.

Abstract

Introduction: US tobacco control policies to reduce cigarette use have been effective, but their impact has been relatively slow. This study considers a strategy of switching cigarette smokers to e-cigarette use ('vaping') in the USA to accelerate tobacco control progress.

Methods: A Status Quo Scenario, developed to project smoking rates and health outcomes in the absence of vaping, is compared with Substitution models, whereby cigarette use is largely replaced by vaping over a 10-year period. We test an Optimistic and a Pessimistic Scenario, differing in terms of the relative harms of e-cigarettes compared with cigarettes and the impact on overall initiation, cessation and switching. Projected mortality outcomes by age and sex under the Status Quo and E-Cigarette Substitution Scenarios are compared from 2016 to 2100 to determine public health impacts.

Findings: Compared with the Status Quo, replacement of cigarette by e-cigarette use over a 10-year period yields 6.6 million fewer premature deaths with 86.7 million fewer life years lost in the Optimistic Scenario. Under the Pessimistic Scenario, 1.6 million premature deaths are averted with 20.8 million fewer life years lost. The largest gains are among younger cohorts, with a 0.5 gain in average life expectancy projected for the age 15 years cohort in 2016.

Conclusions: The tobacco control community has been divided regarding the role of e-cigarettes in tobacco control. Our projections show that a strategy of replacing cigarette smoking with vaping would yield substantial life year gains, even under pessimistic assumptions regarding cessation, initiation and relative harm

Citation

Heckman, B.W., Cummings, K.M., Kasza, K.A., Borland, R., Burris, J.L., Fong, G.T., McNeill, A., Carpenter, M.J. (2017). Effectiveness of switching smoking cessation medications following relapse: A population-based study. American Journal of Preventive Medicine, 53(2), e63-e70.

Abstract

Introduction: Nicotine dependence is a chronic disorder often characterized by multiple failed quit attempts (QAs). Yet, little is known about the sequence of methods used across multiple QAs or how this may impact future ability to abstain from smoking. This prospective cohort study examines the effectiveness of switching smoking-cessation medications (SCMs) across multiple QAs.

Methods: Adult smokers (aged ≥18 years) participating in International Tobacco Control surveys in the United Kingdom, U.S., Canada, and Australia (N=795) who: (1) completed two consecutive surveys between 2006 and 2011; (2) initiated a QA at least 1 month before each survey; and (3) provided data for the primary predictor (SCM use during most recent QA), outcome (1-month point prevalence abstinence), and relevant covariates. Analyses were conducted in 2016.

Results: Five SCM user classifications were identified: (1) non-users (43.5%); (2) early users (SCM used for initial, but not subsequent QA; 11.4%); (3) later users (SCM used for subsequent, but not initial QA; 18.4%); (4) repeaters (same SCM used for both QAs; 10.7%); and (5) switchers (different SCM used for each QA; 14.2%). Abstinence rates were lower for non-users (15.9%, OR=0.48, p=0.002), early users (16.6%, OR=0.27, p=0.03), and repeaters (12.4%, OR=0.36, p=0.004) relative to switchers (28.5%).

Conclusions: Findings suggest smokers will be more successful if they use a SCM in QAs and vary the SCM they use across time. That smokers can increase their odds of quitting by switching SCMs is an important message that could be communicated to smokers.

Citation

Heckman, B.W., Cummings, K.M., Kasza, K.A., Borland, R., Burris, J.L., Fong, G.T., McNeill, A., Carpenter, M.J. (2017). Effectiveness of switching smoking cessation medications following relapse: A population-based study. American Journal of Preventive Medicine, 53(2), e63-e70.

Abstract

Introduction: Nicotine dependence is a chronic disorder often characterized by multiple failed quit attempts (QAs). Yet, little is known about the sequence of methods used across multiple QAs or how this may impact future ability to abstain from smoking. This prospective cohort study examines the effectiveness of switching smoking-cessation medications (SCMs) across multiple QAs.

Methods: Adult smokers (aged ≥18 years) participating in International Tobacco Control surveys in the United Kingdom, U.S., Canada, and Australia (N=795) who: (1) completed two consecutive surveys between 2006 and 2011; (2) initiated a QA at least 1 month before each survey; and (3) provided data for the primary predictor (SCM use during most recent QA), outcome (1-month point prevalence abstinence), and relevant covariates. Analyses were conducted in 2016.

Results: Five SCM user classifications were identified: (1) non-users (43.5%); (2) early users (SCM used for initial, but not subsequent QA; 11.4%); (3) later users (SCM used for subsequent, but not initial QA; 18.4%); (4) repeaters (same SCM used for both QAs; 10.7%); and (5) switchers (different SCM used for each QA; 14.2%). Abstinence rates were lower for non-users (15.9%, OR=0.48, p=0.002), early users (16.6%, OR=0.27, p=0.03), and repeaters (12.4%, OR=0.36, p=0.004) relative to switchers (28.5%).

Conclusions: Findings suggest smokers will be more successful if they use a SCM in QAs and vary the SCM they use across time. That smokers can increase their odds of quitting by switching SCMs is an important message that could be communicated to smokers.

Citation

Levy, D., Borland, R., Fong, G.T., Villanti, A.C., Niaura, R., Meza, R., Holford, T.R., Cummings, K.M., Abrams, D.B. (2017). Developing consistent and transparent models of e-cigarette use: Reply to Glantz and Soneji et al. Nicotine and Tobacco Research, 19(2), 268-270.

There is no abstract available for this publication.

Citation

Cooper, J., Borland, R., McKee, S., Yong, H.H., Dugué, P.A. (2016). Depression motivates quit attempts but predicts relapse: Differential findings for gender from the International Tobacco Control Study. Addiction, 111(8), 1438-47.

Abstract

Aims: To determine whether signs of current depression predict attempts to quit smoking, and short-term abstinence among those who try, and to test moderating effects of gender and cessation support (pharmacological and behavioural).

Design: Prospective cohort with approximately annual waves. Among smokers at one wave we assessed outcomes at the next wave using mixed-effects logistic regressions.

Setting: Waves 5-8 of the Four Country International Tobacco Control Study: a quasi-experimental cohort study of smokers from Canada, USA, UK and Australia.

Participants: A total of 6811 tobacco smokers who participated in telephone surveys.

Measurements: Three-level depression index: (1) neither low positive affect (LPA) nor negative affect (NA) in the last 4 weeks; (2) LPA and/or NA but not diagnosed with depression in the last 12 months; and (3) diagnosed with depression. Outcomes were quit attempts and 1-month abstinence among attempters.

Findings: Depression positively predicted quit attempts, but not after controlling for quitting history and motivational variables. Controlling for all covariates, depression consistently negatively predicted abstinence. Cessation support did not moderate this effect. There was a significant interaction with gender for quit attempts (P = 0.018) and abstinence (P = 0.049) after controlling for demographics, but not after all covariates. Depression did not predict abstinence among men. Among women, depressive symptoms [odds ratio (OR) = 0.63, 95% confidence interval (CI) = 0.49-0.81] and diagnosis (OR = 0.46, 95% CI = 0.34-0.63) negatively predicted abstinence.

Conclusions: Smokers with depressive symptoms or diagnosis make more quit attempts than their non-depressed counterparts, which may be explained by higher motivation to quit, but they are also more likely to relapse in the first month. These findings are stronger in women than men.

Citation

Guindon, E., Burkhalter, R., Brown, S.K. (2016). Levels and trends in cigarette contraband in Canada. Tobacco Control, 26(5), 518-525.

Abstract

Background: There is overwhelming evidence that increases in tobacco taxes reduce tobacco use, save lives and increase government tax revenue. High taxes, however, create an incentive to devise ways to avoid or evade tobacco taxes through contraband tobacco. The associated consequences are significant and call for an accurate measurement of contraband's magnitude. However, its illegal nature makes the levels and trends in contraband intrinsically difficult to measure accurately.

Objective: To examine levels and trends in cigarette contraband in Canada.

Methods: We employed 2 approaches: first, we contrasted estimates of tax-paid cigarettes sales with consumption estimates based on survey data; second, we used data from several individual-level surveys that examined smokers' purchasing and use behaviours. We placed a particular emphasis on the provinces of Québec and Ontario because existing research suggests that cigarette contraband levels are far higher than in any other province.

Results: The estimates presented show a clear upward trend from the early 2000s in cigarette contraband in Québec and Ontario followed by, on the whole, a decreasing trend from about 2007 to 2009. None of the data presented provide support to the narrative that cigarette contraband has been increasing in recent years. Of note are Québec estimates which suggest relatively low levels of cigarette contraband since 2010, at levels no higher than in the early 2000s.

Conclusions: The data presented suggest that policies to tackle cigarette contraband introduced from the mid-2000s to late 2000s, at both federal and provincial levels, may have dampened the demand for contraband cigarettes.

Citation

Cooper, J., Borland, R., Yong, H.H., Fotuhi, O. (2016). The impact of quitting smoking on depressive symptoms: Findings from the International Tobacco Control Four-Country Survey. Addiction, 111(8), 1448-1456.

Abstract

Aims: To determine whether abstinence or relapse on a quit attempt in the previous year is associated with current depressive symptoms.

Design: Prospective cohort with approximately annual waves. Mixed effect logistic regressions tested whether Time 2 (T2) quitting status was associated with reporting symptoms at T2, and whether Time 1 (T1) symptoms moderated this relationship.

Setting: Waves 5 to 8 of the Four Country International Tobacco Control Study: a quasi-experimental cohort study of smokers from Canada, USA, UK and Australia.

Participants: 6978 smokers who participated in telephone surveys.

Measurements: T1 and T2 depressive symptoms in the last 4 weeks assessed with two screening items from the PRIME-MD questionnaire. Quitting status at T2: 1) No attempt since T1; 2) Attempted and relapsed; 3) Attempted and abstinent at T2.

Findings: Compared with no attempt, relapse was associated with reporting T2 symptoms (OR = 1.46, 95% CI:1.33,1.59). Associations between T2 quitting status and T2 symptoms were moderated by T1 symptoms. Relapse was positively associated with T2 symptoms for those without T1 symptoms (OR = 1.71, 95% CI:1.45,2.03) and those with T1 symptoms (OR = 1.45, 95% CI:1.23,1.70). Abstinence was positively associated for those without T1 symptoms (OR = 1.37, 95% CI:1.10,1.71) and negatively associated for those with T1 symptoms (OR = 0.74, 95% CI:0.59,0.94). Age significantly moderated these associations. Relapse did not predict T2 symptoms for those aged 18 to 39 irrespective of T1 symptoms. The negative effect of abstinence on T2 symptoms for those with T1 symptoms was significant only for those aged 18 to 39 (OR = 0.61, 95% CI = 0.40, 0.94) and 40 to 55 (OR = 0.58, 95% CI = 0.40, 0.84). The positive effect of abstinence on T2 symptoms for those without T1 symptoms was significant only for those aged over 55 (OR = 1.97, 95% CI = 1.35, 2.87).

Conclusions: Most people who stop smoking appear to be at no greater risk of developing symptoms of depression than if they had continued smoking. However, people over age 55 who stop smoking may be at greater risk of developing symptoms of depression than if they had continued smoking.

Citation

Smith, P.H., Kasza, K.A., Hyland, A., Fong, G.T., Borland, R., McNeill, A., Brady, K., Carpenter, M.J., Hartwell, K., Prohmmo, A., McKee, S. (2015). Gender differences in medication use and cigarette smoking cessation: Results from the ITC Four Country Survey. Nicotine & Tobacco Research, 17(4), 463-472

Abstract

Introduction: There is conflicting evidence for gender differences in smoking cessation, and there has been little research on gender differences in smoking cessation medication (SCM) use and effectiveness. Using longitudinal data from the International Tobacco Control Four Country Surveys (ITC-4) conducted in the United Kingdom, the United States, Canada, and Australia, we examined gender differences in the incidence of quit attempts, reasons for quitting, use of SCMs, reasons for discontinuing use of SCMs, and rates of smoking cessation.

Methods: Data were analyzed from adult smokers participating in the ITC-4, annual waves 2006-2011 (n = 7,825), as well as a subsample of smokers (n = 1,079) who made quit attempts within 2 months of survey. Adjusted modeling utilized generalized estimating equations.

Results: There were no gender differences in the likelihood of desire to quit, plans to quit, or quit attempts between survey waves. Among quit attempters, women had 31% lower odds of successfully quitting (OR = 0.69; 95% CI = 0.51, 0.94). Stratified by medication use, quit success was lower among women who did not use any SCMs (OR = 0.59; 95% CI = 0.39, 0.90), and it was no different from men when medications were used (OR = 0.73; 95% CI = 0.46, 1.16). In particular, self-selected use of nicotine patch and varenicline contributed to successful quitting among women.

Conclusions: Women may have more difficulty quitting than men, and SCMs use may help attenuate this difference.

Citation

Cowie, G.A., Swift, E., Partos, T.R., Borland, R. (2015). Quitting activity and tobacco brand switching: Findings from the ITC-4 Country Survey. Australian and New Zealand Journal of Public Health, 39(2), 109-113.

Abstract

Objective: Among Australian smokers, to examine associations between cigarette brand switching, quitting activity and possible causal directions by lagging the relationships in different directions.

Methods: Current smokers from nine waves (2002 to early 2012) of the ITC-4 Country Survey Australian dataset were surveyed. Measures were brand switching, both brand family and product type (roll-your-own versus factory-made cigarettes) reported in adjacent waves, interest in quitting, recent quit attempts, and one month sustained abstinence.

Results: Switching at one interval was unrelated to concurrent quit interest. Quit interest predicted switching at the following interval, but the effect disappeared once subsequent quit attempts were controlled for. Recent quit attempts more strongly predicted switching at concurrent (OR 1.34, 95%CI=1.18-1.52, p<0.001) and subsequent intervals (OR 1.31, 95%CI=1.12-1.53, p=0.001) than switching predicted quit attempts, with greater asymmetry when both types of switching were combined. One month sustained abstinence and switching were unrelated in the same interval; however, after controlling for concurrent switching and excluding type switchers, sustained abstinence predicted lower chance of switching at the following interval (OR=0.66, 95%CI=0.47-0.93, p=0.016).

Conclusions: The asymmetry suggests brand switching does not affect subsequent quitting.

Implications: Brand switching does not appear to interfere with quitting.

Citation

Thrasher, J.F., Osman, A., Moodie, C., Hammond, D., Bansal-Travers, M., Cummings, K.M., Borland, R., Yong, H.H., Hardin, J. (2015). Promoting cessation resources through cigarette package warning labels: A longitudinal survey with adult smokers in Canada, Australia and Mexico. Tobacco Control, 24 (e1), 23-31.

Abstract

Introduction: Health warning labels (HWLs) on tobacco packaging can be used to provide smoking cessation information, but the impact of this information is not well understood.

Methods: Online consumer panels of adult smokers from Canada, Australia and Mexico were surveyed in September 2012, January 2013 and May 2013; replenishment was used to maintain sample sizes of 1000 participants in each country at each wave. Country-stratified logistic Generalised Estimating Equation (GEE) models were estimated to assess correlates of citing HWLs as a source of information on quitlines and cessation websites. GEE models also regressed having called the quitline, and having visited a cessation website, on awareness of these resources because of HWLs.

Results: At baseline, citing HWLs as a source of information about quitlines was highest in Canada, followed by Australia and Mexico (33%, 19% and 16%, respectively). Significant increases over time were only evident in Australia and Mexico. In all countries, citing HWLs as a source of quitline information was significantly associated with self-report of having called a quitline. At baseline, citing HWLs as a source of information about cessation websites was higher in Canada than in Australia (14% and 6%, respectively; Mexico was excluded because HWLs do not include website information), but no significant changes over time were found for either country. Citing HWLs as a source of information about cessation websites was significantly associated with having visited a website in both Canada and Australia.

Conclusions: HWLs are an important source of cessation information.

Citation

Shang, C., Chaloupka, F., Fong, G.T., Thompson, M.E., Siahpush, M., Ridgeway, W. (2014, June). Weight control belief and its impact on cigarettes consumption and quit attempts: Findings from the ITC Project. Oral presentation at the American Society of Health Economists Conference, Los Angeles, California, United States.

Abstract

Background: Weight concerns are widely documented as one of the major barriers for girls and young adult women to quit smoking. Therefore, it is important to investigate whether smokers who have weight concerns respond to tobacco control policies differently than smokers who do not in terms of quit attempts, and how this difference varies by gender and country.

Objective: This study aims to investigate, by gender and country, whether smokers who believe that smoking helps control weight are less responsive to tobacco control policies with regards to quit attempts than those who do not.

Methods: We use longitudinal data from the International Tobacco Control Policy Evaluation Project in the USA, Canada, the UK and Australia to conduct the analysis. We first constructed a dichotomous indicator for smokers who have the weight control belief and then examined the disparity in policy responsiveness in terms of quit attempts by directly estimating the interaction terms of policies and the weight control belief indicator using generalised estimating equations.

Findings: We find that weight control belief significantly attenuates the policy impact of tobacco control measures on quit attempts among US female smokers and among UK smokers. This pattern was not found among smokers in Canada and Australia.

Conclusions: Although our results vary by gender and country, the findings suggest that weight concerns do alter policy responsiveness in quit attempts in certain populations. Policy makers should take this into account and alleviate weight concerns to enhance the effectiveness of existing tobacco control policies on promoting quitting smoking.

Citation

Li, L., Borland, R., Yong, H.H., Prohmmo, A., Thrasher, J.F., Hitchman, S.C., Fong, G.T., Hammond, D., Bansal-Travers, M. (2015). Longer term impact of cigarette package warnings in Australia compared to the United Kingdom and Canada: Findings from the International Tobacco Control (ITC) Four Country Survey. Health Education Research, 30(1), 67-80.

Abstract

This study examines the effects of different cigarette package warnings in Australia, Canada and the United Kingdom up to 5 years post-implementation. The data came from the International Tobacco Control Surveys. Measures included salience of warnings, cognitive responses, forgoing cigarettes and avoiding warnings. Although salience of the UK warnings was higher than the Australian and Canadian pictorial warnings, this did not lead to greater levels of cognitive reactions, forgoing or avoiding. There was no difference in ratings between the Australian and UK warnings for cognitive responses and forgoing, but the Canadian warnings were responded to more strongly. Avoidance of the Australian warnings was greater than to UK ones, but less than to the Canadian warnings. The impact of warnings declined over time in all three countries. Declines were comparable between Australia and the United Kingdom on all measures except avoiding, where Australia had a greater rate of decline; and for salience where the decline was slower in Canada. Having two rotating sets of warnings does not appear to reduce wear-out over a single set of warnings. Warning size may be more important than warning type in preventing wear-out, although both probably contribute interactively.

Citation

Partos, T.R., Borland, R., Thrasher, J.F., Li, L., Yong, H.H., O’Connor, R.J., Siahpush, M. (2014). The predictive utility of micro indicators of concern about smoking: Data from the International Tobacco Control Four Country Survey. Addictive Behaviours, 39(8), 1235-1242.

Abstract

This study explored the association between six “micro indicators” of concern about smoking (1. stubbing out cigarettes before finishing; 2. forgoing cigarettes due to packet warning labels; thinking about… 3. the harms to oneself of smoking; 4. the harms to others of one's smoking; 5. the bad conduct of tobacco companies; and 6. money spent on cigarettes) and cessation outcomes (making quit attempts, and achieving at least six months of sustained abstinence) among adult smokers from Australia, Canada, the United Kingdom, and the United States of America. Participants were 12,049 individuals from five survey waves of the International Tobacco Control Four Country Survey (interviewed between 2002 and 2006, and followed-up approximately one year later). Generalized estimating equation logistic regression analysis was used, enabling us to control for within participant correlations due to possible multiple responses by the same individual over different survey waves. The frequency of micro indicators predicted making quit attempts, with premature stubbing out, forgoing, and thinking about the harms to oneself of smoking being particularly strong predictors. An interaction effect with expressed intention to quit was observed, such that stubbing out and thinking about the harms on oneself predicted quit attempts more strongly among smokers with no expressed plans to quit. In contrast, there was a negative association between some micro indicators and sustained abstinence, with more frequent stubbing out, forgoing, and thinking about money spent on cigarettes associated with a reduced likelihood of subsequently achieving sustained abstinence. In countries with long-established tobacco control programs, micro indicators index both high motivation by smokers to do something about their smoking at least partly independent of espoused intention and, especially those indicators not part of a direct pathway to quitting, reduced capacity to quit successfully.

Citation

Hall, P.A., Fong, G.T., Meng, G. (2014). Time perspective as a determinant of smoking cessation in four countries: Direct and mediated effects from the International Tobacco Control (ITC) 4-Country Surveys. Addictive Behaviours, 39(7), 1183-1190.

Abstract

Background: Future oriented time perspective predicts a number of important health behaviors and outcomes, including smoking cessation. However, it is not known how future orientation exerts its effects on such outcomes, and no large scale cross-national studies have examined the question prospectively. The aim of the current investigation was to examine the relationship between time perspective and success in smoking cessation, and social cognitive mediators of the association.

Methods: The ITC-4 is a multi-wave, four country survey (Australia, Canada, United States, United Kingdom) of current smokers (N=9772); the survey includes baseline measurements of time perspective, intentions, quit attempts, and self-reported quit status at follow-up over 8years. We examined the predictive power of time perspective for smoking cessation, as mediated through strength of quit intentions and prior history of quit attempts.

Results: Findings indicated that those smokers with a stronger future orientation at baseline were more likely to have successfully quit at follow-up. This effect was partially explained by intention-mediated effects of future orientation on quit attempts. CONCLUSIONS: Future orientation predicts smoking cessation across four English-speaking countries; the cessation-facilitating effects of future orientation may be primarily due to future oriented individuals' motivated and sustained involvement in the quit cycle over time.

Citation

Hitchman, S.C., Fong, G.T., Zanna, M.P., Thrasher, J.F., Laux, F. (2014). The relation between number of smoking friends, and quit intentions, attempts, and success: Findings from the International Tobacco Control (ITC) Four Country Survey. Psychology of Addictive Behaviours, 28(4), 1144-1152.

Abstract

Smokers who inhabit social contexts with a greater number of smokers may be exposed to more positive norms toward smoking and more cues to smoke. This study examines the relation between number of smoking friends and changes in number of smoking friends, and smoking cessation outcomes. Data were drawn from Wave 1 (2002) and Wave 2 (2003) of the International Tobacco Control (ITC) Project Four Country Survey, a longitudinal cohort survey of nationally representative samples of adult smokers in Australia, Canada, United Kingdom, and United States (N = 6,321). Smokers with fewer smoking friends at Wave 1 were more likely to intend to quit at Wave 1 and were more likely to succeed in their attempts to quit at Wave 2. Compared with smokers who experienced no change in their number of smoking friends, smokers who lost smoking friends were more likely to intend to quit at Wave 2, attempt to quit between Wave 1 and Wave 2, and succeed in their quit attempts at Wave 2. Smokers who inhabit social contexts with a greater number of smokers may be less likely to successfully quit. Quitting may be particularly unlikely among smokers who do not experience a loss in the number of smokers in their social context.

Citation

Shang, C., Chaloupka, F., Zahra, N., Fong, G.T. (2014). The distribution of cigarette prices under different tax structures: Findings from the International Tobacco Control Policy Evaluation (ITC) Project. Tobacco Control, 23(Suppl 1), i23-i29.

Abstract

Background: The distribution of cigarette prices has rarely been studied and compared under different tax structures. Descriptive evidence on price distributions by countries can shed light on opportunities for tax avoidance and brand switching under different tobacco tax structures, which could impact the effectiveness of increased taxation in reducing smoking.

Objective: This paper aims to describe the distribution of cigarette prices by countries and to compare these distributions based on the tobacco tax structure in these countries.

Methods: We employed data for 16 countries taken from the International Tobacco Control Policy Evaluation Project to construct survey-derived cigarette prices for each country. Self-reported prices were weighted by cigarette consumption and described using a comprehensive set of statistics. We then compared these statistics for cigarette prices under different tax structures. In particular, countries of similar income levels and countries that impose similar total excise taxes using different tax structures were paired and compared in mean and variance using a two-sample comparison test.

Findings: Our investigation illustrates that, compared with specific uniform taxation, other tax structures, such as ad valorem uniform taxation, mixed (a tax system using ad valorem and specific taxes) uniform taxation, and tiered tax structures of specific, ad valorem and mixed taxation tend to have price distributions with greater variability. Countries that rely heavily on ad valorem and tiered taxes also tend to have greater price variability around the median. Among mixed taxation systems, countries that rely more heavily on the ad valorem component tend to have greater price variability than countries that rely more heavily on the specific component. In countries with tiered tax systems, cigarette prices are skewed more towards lower prices than are prices under uniform tax systems. The analyses presented here demonstrate that more opportunities exist for tax avoidance and brand switching when the tax structure departs from a uniform specific tax.

Citation

Huang, J., Chaloupka, F., Fong, G.T. (2014). Cigarette graphic warning labels and smoking preference in Canada: A critical examination and reformulation of the FDA regulatory impact analysis. Tobacco Control, 23(Suppl 1), i7-i12.

Abstract

Background: The estimated effect of cigarette graphic warning labels (GWL) on smoking rates is a key input to the Food and Drug Administration's (FDA) regulatory impact analysis (RIA), required by law as part of its rulemaking process. However, evidence on the impact of GWLs on smoking prevalence is scarce.

Objective: The goal of this paper is to critically analyse FDA's approach to estimating the impact of GWLs on smoking rates in its RIA, and to suggest a path forward to estimating the impact of the adoption of GWLs in Canada on Canadian national adult smoking prevalence.

Methods: A quasi-experimental methodology was employed to examine the impact of adoption of GWLs in Canada in 2000, using the USA as a control.

Findings: We found a statistically significant reduction in smoking rates after the adoption of GWLs in Canada in comparison with the USA. Our analyses show that implementation of GWLs in Canada reduced smoking rates by 2.87-4.68 percentage points, a relative reduction of 12.1-19.6%; 33-53 times larger than FDA's estimates of a 0.088 percentage point reduction. We also demonstrated that FDA's estimate of the impact was flawed because it is highly sensitive to the changes in variable selection, model specification, and the time period analysed.

Conclusions: Adopting GWLs on cigarette packages reduces smoking prevalence. Applying our analysis of the Canadian GWLs, we estimate that if the USA had adopted GWLs in 2012, the number of adult smokers in the USA would have decreased by 5.3-8.6 million in 2013. Our analysis demonstrates that FDA's approach to estimating the impact of GWLs on smoking rates is flawed. Rectifying these problems before this approach becomes the norm is critical for FDA's effective regulation of tobacco products.

Citation

Yong, H.H., Thompson, M.E., Thrasher, J.F., Borland, R., Fong, G.T., Hammond, D., Cummings, K.M., Nagelhout, G.E., Meng, G., McNeill, A. (2014). Mediational pathways of the impact of cigarette warning labels on quit attempts. Health Psychology, 33(11), 1410-1420.

Abstract

Objective: To test and develop, using structural equation modeling, a robust model of the mediational pathways through which health warning labels exert their influence on smokers' subsequent quitting behavior.

Method: Data come from the International Tobacco Control Four-Country Survey, a longitudinal cohort study conducted in Australia, Canada, the United Kingdom, and the United States. Waves 5-6 data (n = 4,988) were used to calibrate the hypothesized model of warning label impact on subsequent quit attempts via a set of policy-specific and general psychosocial mediators. The finalized model was validated using Waves 6-7 data (n = 5065).

Results: As hypothesized, warning label salience was positively associated with thoughts about risks of smoking stimulated by the warnings (β = .58, p < .001), which in turn were positively related to increased worry about negative outcomes of smoking (β = .52, p < .001); increased worry in turn predicted stronger intention to quit (β = .39, p < .001), which was a strong predictor of subsequent quit attempts (β = .39, p < .001). This calibrated model was successfully replicated using Waves 6-7 data.

Conclusion: Health warning labels seem to influence future quitting attempts primarily through their ability to stimulate thoughts about the risks of smoking, which in turn help to raise smoking-related health concerns, which lead to stronger intentions to quit, a known key predictor of future quit attempts for smokers. By making warning labels more salient and engaging, they should have a greater chance to change behavior.

Citation

Hitchman, S.C., Fong, G.T., Zanna, M.P., Thrasher, J.F., Chung-Hall, J., Siahpush, M. (2014). Socioeconomic status and smokers' number of smoking friends: Findings from the International Tobacco Control (ITC) Four Country Survey. Drug and Alcohol Dependence, 143, 158-166.

Abstract

Background: Smoking rates are higher among low socioeconomic (SES) groups, and there is evidence that inequalities in smoking are widening over time in many countries. Low SES smokers may be more likely to smoke and less likely to quit because smoking is heavily concentrated in their social contexts. This study investigated whether low SES smokers (1) have more smoking friends, and (2) are more likely to gain and less likely to lose smoking friends over time. Correlates of having more smoking friends and gaining or losing smoking friends were also considered.

Method: Respondents included 6321 adult current smokers (at recruitment) from Wave 1 (2002) and Wave 2 (2003) of the International Tobacco Control Project (ITC) Four Country Survey, a nationally representative longitudinal cohort survey of smokers in Australia, Canada, UK, and US.

Results: Low SES smokers reported more smoking friends than moderate and high SES smokers. Low SES smokers were also more likely to gain smoking friends over time compared with high SES smokers. Smokers who were male, younger, and lived with other smokers reported more smoking friends, and were also more likely to gain and less likely to lose smoking friends. Smoking behaviours, such as higher nicotine dependence were related to reporting more smoking friends, but not to losing or gain smoking friends.

Conclusions: Smoking is highly concentrated in the social networks of lower SES smokers and this concentration may be increasing over time. Cessation interventions should consider how the structure of low SES smokers' social networks affects quitting.

Citation

Mutti, S., Kennedy, R.D., Thompson, M.E., Fong, G.T. (2014). Prepaid monetary incentives - Predictors of taking the money and completing the survey: Results from the International Tobacco Control (ITC) Four-Country Survey. Sociological Methods & Research, 43(2), 338-355.

Abstract

Prepaid monetary incentives are used to address declining response rates in random-digit dial surveys. There is concern among researchers that some respondents will accept the prepayment but not complete the survey. There is little research to understand check cashing and survey completing behaviors among respondents who receive prepayment. Data from the International Tobacco Control Four-Country Study—a longitudinal survey of smokers in Canada, the United States, the United Kingdom, and Australia—were used to examine the impact of prepayment (in the form of checks, approximately US$10) on sample profile. Approximately 14 percent of respondents cashed their check, but did not complete the survey, while about 14 percent did not cash their checks, but completed the survey. Younger adults (Canada and United States), those of minority status (United States), and those who had been in the survey for only two waves or less (Canada and United States) were more likely to cash their checks and not complete the survey.

Citation

Gravely, S., Fong, G.T., Cummings, K.M., Yan, M., Quah, A.C.K., Borland, R., Yong, H.H., Hitchman, S.C., McNeill, A., Hammond, D., Thrasher, J.F., Willemsen, M.C., Seo, H.G., Jiang, Y., Cavalcante, T.M., Perez, C., Omar, M., Hummel, K. (2015). Awareness, trial, and current use of electronic cigarettes in 10 countries: findings from the ITC Project. International Journal of Environmental Research and Public Health, 12(5), 4631-4637.

Abstract

Background: In recent years, electronic cigarettes (e-cigarettes) have generated considerable interest and debate on the implications for tobacco control and public health. Although the rapid growth of e-cigarettes is global, at present, little is known about awareness and use. This paper presents self-reported awareness, trial and current use of e-cigarettes in 10 countries surveyed between 2009 and 2013; for six of these countries, we present the first data on e-cigarettes from probability samples of adult smokers.

Methods: A cross-sectional analysis of probability samples of adult (≥ 18 years) current and former smokers participating in the International Tobacco Control (ITC) surveys from 10 countries. Surveys were administered either via phone, face-to-face interviews, or the web. Survey questions included sociodemographic and smoking-related variables, and questions about e-cigarette awareness, trial and current use.

Results: There was considerable cross-country variation by year of data collection and for awareness of e-cigarettes (Netherlands (2013: 88%), Republic of Korea (2010: 79%), United States (2010: 73%), Australia (2013: 66%), Malaysia (2011: 62%), United Kingdom (2010: 54%), Canada (2010: 40%), Brazil (2013: 35%), Mexico (2012: 34%), and China (2009: 31%)), in self-reports of ever having tried e-cigarettes (Australia, (20%), Malaysia (19%), Netherlands (18%), United States (15%), Republic of Korea (11%), United Kingdom (10%), Mexico (4%), Canada (4%), Brazil (3%), and China (2%)), and in current use (Malaysia (14%), Republic of Korea (7%), Australia (7%), United States (6%), United Kingdom (4%), Netherlands (3%), Canada (1%), and China (0.05%)).

Conclusions: The cross-country variability in awareness, trial, and current use of e-cigarettes is likely due to a confluence of country-specific market factors, tobacco control policies and regulations (e.g., the legal status of e-cigarettes and nicotine), and the survey timing along the trajectory of e-cigarette awareness and trial/use in each country. These ITC results constitute an important snapshot of an early stage of what appears to be a rapid progression of global e-cigarette use.

Abstract

Introduction: The Heaviness of Smoking Index (HSI) is the measure of dependence most strongly predictive of relapse. However, recent research suggests it may not be predictive of longer term relapse. Our aim was to examine its predictive power over the first 2 years after quitting and explore whether use of stop-smoking medications is a moderator.

Methods: Data (n = 7,093) came from the first 7 waves (2002-2009) of the International Tobacco Control Four-Country Survey, an annual cohort survey of smokers in Canada, United States, United Kingdom, and Australia. HSI and its 2 components (cigarettes per day [CPD] and time to first cigarette [TTFC]) were used to predict smoking relapse risk in the 2 years after the start of a quit attempt.

Results: Scores on HSI and its components all strongly predicted relapse, but there was an interaction with time (p < .001). These measures were strong predictors of relapse within the first week of quitting (hazard ratios [HR] = 1.17, 1.24, and 1.30 for HSI, CPD, and TTFC, respectively, all p < .001), less predictive of relapse occurring between 1 week and 1 month, and not clearly predictive beyond 1 month. Among those using medication to quit, hazard ratio for HSI (HR = 1.11, p < .001) was significantly lower than for those not using (HR = 1.24, p < .001) in the first week, but not beyond.

Conclusions: HSI and its 2 components are strong predictors of short-term smoking relapse, but they rapidly lose predictive power over the first weeks of an attempt, becoming marginally significant at around 1 month, and not clearly predictive beyond that.