Scientific Journal Articles
Showing 51-75 of 157 Results
Smith, et al. 2015. Gender differences in mediation use and cigarette smoking cessation: Results from the ITC Four Country Survey [access full article]
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.[download PDF]
Cowie, et al. 2015. Quitting activity and tobacco brand switching: Findings from the ITC 4-Country Survey [access full article]
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.[download PDF]
Thrasher, et al. 2015. Promoting cessation resources through cigarette package warning labels: A longitudinal survey with adult smokers in Canada, Australia, and Mexico [access full article]
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.[download PDF]
Li, et al. 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 [access full article]
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.[download PDF]
Shang, et al. 2015. Weight control belief and its impact on the effectiveness of tobacco control policies on quit attempts: Findings from the ITC 4 Country Project [access full article]
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.[download PDF]
Partos, et al. 2014. The predictive utility of micro indicators of concern about smoking: Data from the International Tobacco Control 4-Country Survey [access full article]
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.[download PDF]
Hall, et al. 2014. Time perspective as a determinant of smoking cessation in four countries: Direct and mediated effects from the International Tobacco Control (ITC) 4-Country Survey [access full article]
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.[download PDF]
Hitchman, et al. 2014. The relation between number of smoking friends, and quit intentions, attempts, and success: Findings from the International Tobacco Control (ITC) Four Country Survey [access full article]
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.[download PDF]
Ce, et al. 2014. The distribution of cigarette prices under different tax structures: Findings from the International Tobacco Control Policy Evaluation (ITC) Project [access full article]
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.[download PDF]
Yong, et al. 2014. Mediational pathways of cigarette warning labels' impact on smoking cessation attempts in four countries: An application of the International Tobacco Control (ITC) Conceptual Model [access full article]
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.[download PDF]
Hitchman, et al. 2014. Socioeconomic status and smokers' number of smoking friends: Findings from the International Tobacco Control (ITC) Four Country Survey [access full article]
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.[download PDF]
Mutti, et al. 2014. Prepaid monetary incentives—Predictors of taking the money and completing the survey: Results from the International Tobacco Control (ITC) Four-Country Survey [access full article]
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.[download PDF]
Gravely, et al. 2014. Awareness, trial, and current use of electronic cigarettes in 10 countries: Findings from the ITC Project [access full article]
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.[download PDF]
Yong, et al. 2014. Heaviness of Smoking Index only predicts smoking abstinence in the first month of a quit attempt: Findings from the International Tobacco Control Four Country Survey [access full article]
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.[download PDF]
Balmford, et al. 2014. Reported planning before and after quitting and quit success: Retrospective data from the ITC 4-Country Survey [access full article]
Planning before quitting smoking is widely believed to be beneficial and is usually recommended in cessation counseling, but there is little evidence on the efficacy of specific planning activities. Using data from 1140 respondents who reported quit attempts at Wave 8 of the ITC 4-Country Survey, we analyzed use of 8 specific planning strategies before (5) and after (3) implementation of a quit attempt, in relation to cessation outcomes, delay in implementation of the attempt, and recent quitting history. Most participants reported some planning both before and after quitting, even among those reporting quitting ‘spontaneously.’ Younger smokers, those who cut down before quitting, and users of stop-smoking medication were more likely to report planning. Those who planned prequit were also more likely to plan postquit. Unexpectedly, we found no clear benefit of planning on short-term (1 month) cessation outcomes, whereas one prequit strategy (practicing not smoking) was negatively related to outcome. There was evidence for a predicted moderating effect of recent quitting experience on planning for the prequit task ‘practice replacement strategies.’ This predicted quit success among those with multiple quit attempts in the past year, but failure among those without. This finding suggests that the quality of planning may be critical. More research, particularly on the moderating effect of quit experience, and where measures of planning are collected before outcomes become evident, is needed before clear recommendations can be made on the utility of various forms of planning for the success of quit attempts.[download PDF]
Huang, et al. 2014. Cigarette graphic warning labels and smoking prevalence in Canada: A critical examination and reformulation of the FDA regulatory impact analysis
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.[download PDF]
Hitchman, et al. 2013. Changes in effectiveness of cigarette health warnings over time in Canada and the United States, 2002-2011 [access full article]
Introduction: Article 11 of the World Health Organization's Framework Convention on Tobacco Control (FCTC) requires countries to implement health warnings on tobacco products. The Article 11 Guidelines advise countries to periodically rotate warnings to prevent “wearout” of the health warnings. This study investigates potential wearout of cigarette health warnings over a period of 9 years in 2 countries: Canada, where larger pictorial warnings were implemented approximately 1 year prior to the study, and in the United States, where small text-only warnings were in place for 17 years at the beginning of the study.
Methods: Data were drawn from national samples of smokers from the International Tobacco Control (ITC) Surveys in Canada (N = 5,309), and the United States (N = 6,412) recruited originally by telephone using random digit dialing. Changes in 4 measures of health warning effectiveness and in a composite Labels Impact Index were examined over 8 waves of survey data (2002-2011). Analyses were conducted in 2012.
Results: The health warning effectiveness measures and the Labels Impact Index indicated that the effectiveness of both the Canadian, and the U.S. warnings declined significantly over time. The Canadian warnings showed greater declines in effectiveness than the U.S. warnings, likely due to the initial novelty of the Canadian warnings. Despite the greater decline in Canada, the Canadian pictorial warnings were significantly more effective than the U.S. text-only warnings throughout the study.
Conclusions: Health warnings decline in effectiveness over time. Health warnings on tobacco products should be changed periodically to maintain effectiveness.[download PDF]
Li, et al. 2013. Impact of point-of-sale tobacco display bans: Findings from the International Tobacco Control Four Country Survey [access full article]
This study examined the impact of point-of-sale (POS) tobacco marketing restrictions in Australia and Canada, in relation to the United Kingdom and the United States where there were no such restrictions during the study period (2006–10). The data came from the International Tobacco Control Four Country Survey, a prospective multi-country cohort survey of adult smokers. In jurisdictions where POS display bans were implemented, smokers’ reported exposure to tobacco marketing declined markedly. From 2006 to 2010, in Canada, the percentages noticing POS tobacco displays declined from 74.1 to 6.1% [adjusted odds ratio (OR)¼0.26, P<0.001]; and reported exposure to POS tobacco advertising decreased from 40.3 to 14.1% (adjusted OR¼0.61, P<0.001). Similarly, in Australia, noticing of POS displays decreased from 73.9 to 42.9%. In contrast, exposure to POS marketing in the United States and United Kingdom remained high during this period. In parallel, there were declines in reported exposures to other forms of advertising/promotion in Canada and Australia, but again, not in the United States or United Kingdom. Impulse purchasing of cigarettes was lower in places that enacted POS display bans. These findings indicate that implementing POS tobacco display bans does result in lower exposure to tobacco marketing and less frequent impulse purchasing of cigarettes.[download PDF]
Nargis, et al. 2013. The choice of discount brand cigarettes: A comparative analysis of International Tobacco Control Surveys in Canada and the USA (2002-2005) [access full article]
Background: Increasing tobacco taxes to increase price is a proven tobacco control measure. This article investigates how smokers respond to tax and price increases in their choice of discount brand cigarettes versus premium brands.
Objective: To estimate how increase in the tax rate can affect smokers' choice of discount brands versus premium brands.
Methods: Using data from International Tobacco Control surveys in Canada and the USA, a logit model was constructed to estimate the probability of choosing discount brand cigarettes in response to its price changes relative to premium brands, controlling for individual-specific demographic and socioeconomic characteristics and regional effects. The self-reported price of an individual smoker is used in a random-effects regression model to impute price and to construct the price ratio for discount and premium brands for each smoker, which is used in the logit model.
Findings: An increase in the ratio of price of discount brand cigarettes to the price of premium brands by 0.1 is associated with a decrease in the probability of choosing discount brands by 0.08 in Canada. No significant effect is observed in case of the USA.
Conclusions: The results of the model explain two phenomena: (1) the widened price differential between premium and discount brand cigarettes contributed to the increased share of discount brand cigarettes in Canada in contrast to a relatively steady share in the USA during 2002-2005 and (2) increasing the price ratio of discount brands to premium brands-which occurs with an increase in specific excise tax-may lead to upward shifting from discount to premium brands rather than to downward shifting. These results underscore the significance of studying the effectiveness of tax increases in reducing overall tobacco consumption, particularly for specific excise taxes.[download PDF]
Partos, et al. 2013. Cigarette packet warning labels can prevent relapse: Findings from the International Tobacco Control 4-Country Policy Evaluation Cohort Study [access full article]
Objectives: To investigate the links between health warning labels (WLs) on cigarette packets and relapse among recently quit smokers.
Design: Prospective longitudinal cohort survey.
Setting: Australia, Canada, the UK and the USA.
Participants: 1936 recent ex-smokers (44.4% male) from one of the first six waves (2002–2007) of the International Tobacco Control 4-Country policy evaluation survey, who were followed up in the next wave.
Main outcome measures: Whether participants had relapsed at follow-up (approximately 1 year later).
Results: In multivariate analysis, very frequent noticing of WLs among ex-smokers was associated with greater relapse 1 year later (OR: 1.52, 95% CI 1.11 to 2.09, p<0.01), but this effect disappeared after controlling for urges to smoke and self-efficacy (OR: 1.29, 95% CI 0.92 to 1.80, p=0.135). In contrast, reporting that WLs make staying quit ‘a lot’ more likely (compared with ‘not at all’ likely) was associated with a lower likelihood of relapse 1 year later (OR: 0.65, 95% CI 0.49 to 0.86, p<0.01) and this effect remained robust across all models tested, increasing in some.
Conclusions: This study provides the first longitudinal evidence that health warnings can help ex-smokers stay quit. Once the authors control for greater exposure to cigarettes, which is understandably predictive of relapse, WL effects are positive. However, it may be that ex-smokers need to actively use the health consequences that WLs highlight to remind them of their reasons for quitting, rather than it being something that happens automatically. Ex-smokers should be encouraged to use pack warnings to counter urges to resume smoking. Novel warnings may be more likely to facilitate this.[download PDF]
Kasza, et al. 2013. Effectiveness of stop-smoking medications: Findings from the International Tobacco Control (ITC) Four Country Survey
Aim: To evaluate the population effectiveness of stop-smoking medications while accounting for potential recall bias by controlling for quit attempt recency.
Design: Prospective cohort survey.
Setting: United Kingdom, Canada, Australia and the United States.
Participants: A total of 7436 adult smokers (18+ years) selected via random digit dialling and interviewed as part of the International Tobacco Control Four Country Survey (ITC-4) between 2002 and 2009. Primary analyses utilized the subset of respondents who participated in 2006 or later (n = 2550).
Measurements: Continuous abstinence from smoking for 1 month/6 months.
Findings: Among participants who recalled making a quit attempt within 1 month of interview, those who reported using varenicline, bupropion or nicotine patch were more likely to maintain 6-month continuous abstinence from smoking compared to those who attempted to quit without medication [adjusted odds ratio (OR) 5.84, 95% confidence interval (CI) (2.12–16.12), 3.94 (0.87–17.80), 4.09 (1.72–9.74), respectively]; there were no clear effects for oral NRT use. Those who did not use any medication when attempting to quit tended to be younger, to be racial/ethnic minorities, to have lower incomes and to believe that medications do not make quitting easier.
Conclusions: Consistent with evidence from randomized controlled trials, smokers in the United Kingdom, Canada, Australia and the United States are more likely to succeed in quit attempts if they use varenicline, bupropion or nicotine patch. Previous population studies that failed to find an effect failed to control adequately for important sources of bias.[download PDF]
McKee, et al. 2013. Longitudinal associations between smoking cessation medications and alcohol consumption among smokers in the International Tobacco Control Four Country Survey [access full article]
Background: Available evidence suggests that quitting smoking does not alter alcohol consumption. However, smoking cessation medications may have a direct impact on alcohol consumption independent of any effects on smoking cessation. Using an international longitudinal epidemiological sample of smokers, we evaluated whether smoking cessation medications altered alcohol consumption independent of quitting smoking.
Methods: Longitudinal data were analyzed from the International Tobacco Control Four Country (ITC-4) Survey between 2007 and 2008, a telephone survey of nationally representative samples of smokers from the United Kingdom, Australia, Canada, and the United States (n = 4,995). Quantity and frequency of alcohol consumption, use of smoking cessation medications (varenicline, nicotine replacement [NRT], and no medications), and smoking behavior were assessed across 2 yearly waves. Controlling for baseline drinking and changes in smoking status, we evaluated whether smoking cessation medications were associated with reduced alcohol consumption.
Results: Varenicline was associated with a reduced likelihood of any drinking compared with nicotine replacement (OR = 0.56; 95% CI = 0.34 to 0.94), and consuming alcohol once a month or more compared to nicotine replacement (OR = 0.43; 95% CI = 0.27 to 0.69) or no medication (OR = 0.63; 95% CI = 0.41 to 0.99). Nicotine replacement was associated with an increased likelihood of consuming alcohol once a month or more compared to no medication (OR = 1.14; 95% CI = 1.03 to 1.25). Smoking cessation medications were not associated with more frequent drinking (once a week or more) or typical quantity consumed per episode. Medication effects on drinking frequency were independent of smoking cessation.
Conclusions: This epidemiological investigation demonstrated that varenicline was associated with a reduced frequency of alcohol consumption. Continued work should clarify under what conditions nicotine replacement therapies may increase or decrease patterns of alcohol consumption.[download PDF]
Adkison, et al. 2013. Electronic nicotine delivery systems: International Tobacco Control Four-Country Survey
Background: Electronic nicotine delivery systems (ENDS) initially emerged in 2003 and have since become widely available globally, particularly over the Internet.
Purpose: Data on ENDS usage patterns are limited. The current paper examines patterns of ENDS awareness, use, and product-associated beliefs among current and former smokers in four countries.
Methods: Data come from Wave 8 of the International Tobacco Control Four-Country Survey, collected July 2010 to June 2011 and analyzed through June 2012. Respondents included 5939 current and former smokers in Canada (n_1581); the U.S. (n_1520); the United Kingdom (UK; n_1325); and Australia (n_1513).
Results: Overall, 46.6% were aware of ENDS (U.S.: 73%, UK: 54%, Canada: 40%, Australia: 20%); 7.6% had tried ENDS (16% of those aware of ENDS); and 2.9% were current users (39% of triers). Awareness of ENDS was higher among younger, non-minority smokers with higher incomes who were heavier smokers. Prevalence of trying ENDS was higher among younger, nondaily smokers with a high income and among those who perceived ENDS as less harmful than traditional cigarettes. Current use was higher among both nondaily and heavy (_20 cigarettes per day) smokers. In all, 79.8% reported using ENDS because they were considered less harmful than traditional cigarettes; 75.4% stated that they used ENDS to help them reduce their smoking; and 85.1% reported using ENDS to help them quit smoking.
Conclusions: Awareness of ENDS is high, especially in countries where they are legal (i.e., the U.S. and UK). Because trial was associated with nondaily smoking and a desire to quit smoking, ENDS may have the potential to serve as a cessation aid.[download PDF]
Partos, et al. 2013. The quitting rollercoaster: How recent quitting history affects future cessation outcomes (data from the International Tobacco Control 4-Country Cohort Study)
Introduction: Most smokers have a history of unsuccessful quit attempts. This study used data from 7 waves (2002–2009) of the International Tobacco Control 4-country cohort study to examine the role of smokers’ quitting history (e.g., recency, length, and number of previous quit attempts) on their subsequent likelihood of making a quit attempt and achieving at least 6 months of sustained abstinence.
Methods: Generalized estimating equations were used, allowing for estimation of relationships between variables across repeated observations while controlling for correlations from multiple responses by the same individual (29,682 observations from 13,417 individuals).
Results: The likelihood of a future quit attempt increased independently with recency and number of prior attempts. By contrast, the likelihood of achieving sustained abstinence of at least 6 months was reduced for smokers with a failed quit attempt within the last year (15.1% vs. 27.1% for those without, p < .001). Two or more failed attempts (vs. only one) in the previous year were also associated with a lower likelihood of achieving sustained abstinence (OR: 0.57, 95% CI: 0.38–0.85). Effects persisted after controlling for levels of addiction, self-efficacy to quit, and use of stop-smoking medications.
Conclusions: There appears to be a subset of smokers who repeatedly attempt but fail to remain abstinent from tobacco. Understanding why repeated attempts might be less successful in the long term is an important research priority because it implies a need to tailor treatment approaches for those who are motivated to quit but persistently relapse back to smoking.[download PDF]
Cooper, et al. 2013. Variations in daily cigarette consumption on work days compared with nonwork days and associations with quitting: Findings from the International Tobacco Control Four-Country Survey
Introduction: We explore whether reported daily cigarette consumption differs between work days and nonwork days and whether variation in consumption between work days and nonwork days influences quitting and abstinence from smoking. We also explore whether effects are independent of measures of addiction and smoking restrictions at work and home.
Methods: Data were from 5,732 respondents from the first five waves of the International Tobacco Control FourCountry Survey, occurring between 2002 and 2006. Respondents were current smokers employed outside the home. Variation in daily cigarette consumption on work days compared with nonwork days at one wave was used to predict the likelihood of making an attempt and the likelihood of maintaining a quit attempt for at least a month at the next wave. Generalized estimating equations were used to combine data for multiple waves.
Results: Just under half reported smoking more on a nonwork day, a little over a third reported no difference, and around one fifth reported smoking more on a work day. Controlling for possible confounding factors, smoking more on a work day was associated with making quit attempts. Among people who made a quit attempt, variation in consumption did not consistently predict one month's abstinence, being positive in Australia, but negative in the United Kingdom.
Conclusion: Those who smoke more on work days try to quit more. Country differences for success may be related to the extent of bans on smoking, with those smoking more on work days more likely to succeed where bans in workplaces and public places were more prevalent, such as Australia at the time.[download PDF]