Email updates

Keep up to date with the latest news and content from BMC Public Health and BioMed Central.

Open Access Research article

Prevalence and factors associated with difficulty and intention to quit smoking in Switzerland

Pedro Marques-Vidal12*, João Melich-Cerveira3, Fred Paccaud1, Gérard Waeber4, Peter Vollenweider4 and Jacques Cornuz5

Author Affiliations

1 Institute of Social and Preventive Medicine (IUMSP), Centre Hospitalier Universitaire Vaudois and University of Lausanne, Bugnon 17, 1005 Lausanne, Switzerland

2 Clinical Trials Unit, University Hospital (CHUV), Lausanne, Switzerland

3 Medical Faculty of the University of Lisbon, Lisbon, Portugal

4 Department of Medicine, University Hospital (CHUV), Lausanne, Switzerland

5 Department of Ambulatory Care and Community Medicine, University of Lausanne, Bugnon 44, 1011 Lausanne, Switzerland

For all author emails, please log on.

BMC Public Health 2011, 11:227  doi:10.1186/1471-2458-11-227

The electronic version of this article is the complete one and can be found online at: http://www.biomedcentral.com/1471-2458/11/227


Received:20 September 2010
Accepted:13 April 2011
Published:13 April 2011

© 2011 Marques-Vidal et al; licensee BioMed Central Ltd.

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Background

recent data indicate a slight decrease in the prevalence of smoking in Switzerland, but little is known regarding the intention and difficulty to quit smoking among current smokers. Hence, we aimed to quantify the difficulty and intention to quit smoking among current smokers in Switzerland.

Methods

cross-sectional study including 607 female and 658 male smokers. Difficulty, intention and motivation to quit smoking were assessed by questionnaire.

Results

90% of women and 85% of men reported being "very difficult" or "difficult" to quit smoking. Almost three quarters of smokers (73% of women and 71% of men) intended to quit; however, less than 20% of them were in the preparation stage and 40% were in the precontemplation stage. On multivariate analysis, difficulty to quit was lower among men (Odds ratio and 95% [confidence interval]: 0.51 [0.35-0.74]) and increased with nicotine dependence and number of previous quitting attempts (OR = 3.14 [1.75 - 5.63] for 6+ attempts compared to none). Intention to quit decreased with increasing age (OR = 0.48 [0.30-0.75] for ≥65 years compared to < 45 years) and increased with nicotine dependence, the number of previous quitting attempts (OR = 4.35 [2.76 - 6.83] for 6+ attempts compared to none) and among non-cigarette smokers (OR = 0.51 [0.28 - 0.92]). Motivation to quit was inversely associated with nicotine dependence and positively associated with the number of previous quitting attempts and personal history of lung disease.

Conclusion

over two thirds of Swiss smokers want to quit. However, only a small fraction wishes to do so in the short term. Nicotine dependence, previous attempts to quit or previous history of lung disease are independently associated with difficulty and intention to quit.

Background

Cigarette smoking is the most important modifiable risk factor for premature death in the world causing 5.4 million deaths every year [1], and it is expected that by 2030 an estimated 7.4 to 9.7 million deaths will be attributable to tobacco smoking [1]. In Switzerland, health costs related to smoking have been estimated at 10 billion CHF a year [2]. The Swiss Federal Office of Public Health has launched comprehensive tobacco prevention program focusing on specific interventions and cooperation between partners for tobacco prevention [3], and recent data indicate a slight decrease in the prevalence of smoking [4] but little is known regarding the intention and difficulty to quit smoking among current smokers in Switzerland [5].

Hence, we used the data from a large, population-based, cross-sectional study (CoLaus study) to assess the prevalence and clinical factors related to intention and difficulty to quit smoking among Swiss smokers. The population of Lausanne (from which the CoLaus study is drawn) can be considered as representative of the whole country as a considerable proportion of the Lausanne population is non-Swiss or comes from other cantons: in 2006, out of the 128,231 Lausanne inhabitants, 38% were non-Swiss, 30% came from other cantons (including Italian and German-speaking cantons) and only 32% were actually from the Vaud canton [6].

Methods

Recruitment process and inclusion criteria

This study was focused on current smokers from the CoLaus study, the design of which has been previously described [7]. Briefly, it is a population-based study conducted between 2003 and 2006 which recruited over 6,000 subjects aged 35-75 years in Lausanne, Switzerland. The following inclusion criteria were applied: a) voluntary participation to the examination, including blood sample, b) aged 35-75 years, and c) Caucasian origin defined as having both parents and grand-parents Caucasian (determined by birth place). The Institutional Review Board of the Centre Hospitalier Universitaire Vaudois (CHUV) in Lausanne and the Cantonal Ethics Committee approved the study protocol and signed informed consent was obtained from participants. Participants were asked to attend the outpatient clinic at the CHUV, Lausanne, in the morning after an overnight fast. Data were collected by trained field interviewers during a single visit lasting about 60 minutes. Overall participation rate was 41%.

Smoking status

The amount of tobacco smoked (number of cigarettes, cigarillos, cigars, or pipes per day) was asked and converted into cigarette equivalents. Cigarette equivalents were assessed as described previously [8]: 1 cigarillo or 1 pipe = 2.5 cigarettes; 1 cigar = 5 cigarettes. Smokers who consumed tobacco products other than cigarettes were considered as non-cigarette smokers. Nicotine dependence was assessed by the heaviness of smoking index (HSI) [9]. The HSI is the sum of two categorical measures: number of cigarettes smoked per day (codes 0:0-10 cigarettes per day; 1: 11-20; 2: 21-30; 3: 31+), and time to first cigarette after waking (coded: 0: 61+ minutes; 1: 31-60 min; 2: 6-30 min; 3: 5 min or less). Values for HSI range from 0 to 6.

Difficulty and intention to quit smoking were addressed by questionnaire. The questions included a) difficulty to stop smoking (4 possible answers: "very difficult", "difficult", "easy" and "very easy"; difficulty was considered for the first two answers); b) the number of attempts to quit smoking during the last 12 months and c) intention to quit smoking (4 possible answers: "yes, definitely", "yes"; "no" and "not at all"; intention to quit smoking was considered for the first two answers).

If participants intended to quit smoking, motivation to quit was measured using a modified algorithm [10] of the state of change construct as suggested previously [11] and applied in Switzerland [12]. Briefly, the groups were defined as follows: Precontemplation, not interested in quitting smoking in next 6 months; Contemplation, interested in quitting smoking in next 6 months but not next 30 days; Preparation, interested in quitting smoking in next 30 days.

Other data

Information on demographic data, socio-economic and marital status, lifestyle factors, personal and family history of cardiovascular and lung disease (defined as emphysema and/or chronic bronchitis) was collected. Educational level was categorized into basic, apprenticeship, secondary and university. Participants were then categorized as drinkers if they had consumed at least one alcohol drink the last seven days and as non-drinkers otherwise. Subjects were also categorized according to their level of alcohol consumption: none, low (1-6 drinks/week); moderate (7-13 drinks/week), high (14-34 drinks/week) and very high (≥35 drinks/week) [13]. Participants were considered as physically active if they reported practicing at least 2 hours of leisure-time physical activity per week.

Statistical analysis

Statistical analyses were conducted using Stata v10.1 (Stata Corp, Texas, USA) and SAS v9.2 (SAS, Cary, USA) for Windows. As the number of quitting attempts during the last 12 months was considerably skewed, three groups were made: no attempt, < 6 attempts and ≥6 attempts. Also, HIS values were categorized into low (0-1), medium (2-4) and high (5-6) as suggested [14]. Results were expressed as mean ± standard deviation or as number of participants and (percentage). Bivariate comparisons were performed using the Student's t-test or chi-square test for continuous and discrete variables, respectively. The clinical factors independently and significantly related with difficulty and intention to quit were assessed by stepwise multivariate logistic regression. Statistical significance was considered for p < 0.05.

Results

Characteristics of the sample

Overall, 1385 current smokers were invited to participate, of which 1265 (91%) responded and 1234 (89%) provided complete information on difficulty and intention to quit. The characteristics of the 1234 participants according to gender are summarized in table 1. Men were more educated, more frequently married but less active than women; men also reported a higher frequency of alcohol consumption and of personal history of coronary heart disease than women. Men smoked more and had higher nicotine dependence (assessed by HSI) than women. Men also tended to smoke more frequently tobacco products other than cigarettes, while no differences were found for the number of quitting attempts (table 1). Finally, 19.6% of the participants smoked within 5 minutes after waking up, and 51.4% within 30 minutes, no differences being found between genders (not shown).

Table 1. participants' characteristics, overall and by gender

Factors associated with difficulty and intention to quit

Almost nine out of ten smokers reported difficulty quitting smoking, and two thirds intended to quit. The factors associated with difficulty and intention to quit smoking are summarized in table 2. Difficulty to quit was significantly and positively associated with female gender, personal and family history of lung disease, nicotine dependence (as assessed by heaviness of smoking index) and number of attempts to quit, and negatively associated with leisure-time physical activity. Conversely, no association was found with marital status, education, leisure-time physical activity, alcohol drinker, personal history of coronary heart disease and family history of cardiovascular or lung disease (not shown). Intention to quit was significantly and positively associated with nicotine dependence, number of attempts to quit and personal and family history of lung disease, while it was negatively associated with age and alcohol consumption.

Table 2. factors associated with difficulty and intention to quit smoking

Stepwise multivariate logistic regression was applied to identify the variables significantly associated with difficulty and intention to quitting smoking, and the results are summarized in table 3. Difficulty to quit was lower among men and increased with increasing nicotine dependence and the number of previous quitting attempts. Intention to quit decreased with increasing age and increased with nicotine dependence, the number of previous quitting attempts and among non-cigarette smokers (table 3).

Table 3. multivariate analysis of the factors associated with difficulty, intention and motivation to quit smoking

Factors associated with motivation to quit

Motivation to quit was assessed in the 883 subjects who indicated they wanted to quit (429 women and 454 men). Slightly less than one-fifth (19.5%) of them was in the preparation stage and four out of ten in the precontemplation stage. The factors associated with motivation to quit are summarized in table 4. Nicotine dependence was associated with a lower motivation to quit, while the number of previous quitting attempts and being physically active were positively associated. Conversely, no differences in motivation were found for gender, age group, alcohol consumption or personal/family history of lung disease.

Table 4. factors associated with motivation to quit smoking

Stepwise multivariate logistic regression was applied to identify the variables significantly associated with being in the preparation stage, and the results are summarized in table 3. Nicotine dependence was negatively associated while number of quitting attempts and personal history of lung disease were positively associated with a higher motivation.

Comparison with non-responders

The comparison of responders with non-responders is summarized in table 5. Non-responders were better educated, had a higher prevalence of alcohol consumption and physical activity and a lower frequency of family history of lung disease. Non-responders also smoked considerably less than responders.

Table 5. comparison between responders and non responders

Discussion

There is few data regarding intention to quit smoking in Switzerland. This cross-sectional, population-based study thus provides important information regarding the current intention to quit among current smokers, as well as the associated clinical factors. Furthermore, the ongoing follow-up of the entire CoLaus cohort will enable a better assessment of the factors associated with successful quitting.

Apprentices had a higher smoking prevalence. These findings are in agreement with the literature [15] and might be related to the fact that, compared to their high school counterparts, apprentices receive a monthly wage, are in contact with more adults and are not systematically submitted to smoking bans in their working places, thus making them more prone to start smoking.

Nicotine dependence, assessed by HSI, smoking amount or the percentage of subjects who smoked within 5 minutes after waking up, was within the values reported in the literature. For instance, almost one out of five smokers smoked within 5 minutes after waking, a figure comparable to Poland, the UK or Sweden [16], but lower than Greece [16] and considerably higher than Germany [16] or than previous Swiss studies [5]. Overall, our data indicate that the level of nicotine dependence among smokers in Switzerland is comparable to other countries. The higher nicotine dependence found in this study compared to other Swiss studies might be related to sampling issues, as subjects from other studies were recruited by phone, and it has been suggested that phone surveys tend to underestimate the number of heavy smokers [17].

Almost nine out of ten smokers reported difficulty quitting smoking. In agreement with the literature [18], men reported a lower difficulty quitting smoking. Possible explanations for the increased difficulty in quitting smoking by women are the fear of weight gain after smoking cessation [19] and increased nicotine dependency in women [20], although the last possibility is not substantiated in this study. Increased nicotine dependence and the number of previous attempts to quit were also independently related with difficulty in quitting smoking. As smoking prevalence and smoking amount have been decreasing in Switzerland [4], it is likely that support measures aimed at quitting smoking will become more successful in the future.

Smoking cessation is positively associated with non-cigarette smoking [21], possibly due to the fact that this group may represent smokers in the process of transition to non-smoking. Indeed, in this study, non-cigarette smokers reported a lower difficulty in quitting smoking, but reported also a lower intention to quit, which was further confirmed on multivariate analysis. Possible explanations include their self-reported lower difficulty to quit or the false belief that non-cigarette smoking is less harmful than cigarette smoking, but further studies are needed to better assess this point.

Almost 72% of smokers wished to quit. This value is considerably higher than previously reported for Switzerland [5,22,23], Greece [24], the UK [25], Finland [26] and France [27], lower than Canada [25] and comparable to Australia, the USA [25] and other countries [16]. This high value might be due to the higher nicotine dependence among the study participants as indicated previously. Indeed, nicotine dependence was independently and positively related with intention to quit, a finding in agreement with the literature [14,28]. These findings suggest that heavy smokers are aware of their nicotine dependence and that adequate support should be provided. Similarly, the number of previous quitting attempts was positively related with intention to quit. These findings are in agreement with the literature [29] and suggest that several failures, known to cause frustration and loss of self-esteem in smokers [30], do not deter them from quitting smoking and that support should be provided irrespective of the number of previous quitting attempts. In agreement with the literature [27], personal history of lung disease was also positively related with intention to quit. In fact, health concern is the most frequently mentioned reason for abandoning tobacco consumption found in the literature [31]. Nevertheless, from a Public Health point of view, it would be better to motivate smokers to quit before serious smoking-related health problems arise. Conversely, the fact that old smokers do not wish to stop smoking is in agreement with some literature [25,32] but not with other [24,33] and might be associated with a more tolerant environment, namely if relatives or friends also smoke [18]. Another possible explanation is that elderly smokers do not perceive any benefit from quitting at an advanced age [34] or perceive themselves as less vulnerable to the harms of smoking [35]. Hence, our results indicate that efforts aimed at helping smokers to quit should be started at an early age as the older the smoker, the less likely he/she intended to quit; nevertheless, interventions adequately tailored to elderly smokers also achieve significant quitting rates [36]. Finally, no independent association was found between intention to quit smoking and alcohol consumption, marital status or education. Those findings are in agreement with some studies [24] but not with others [25,26,37,38] and suggest that family environment, alcohol consumption or educational level might exert a lower effect on intention to quit than age, nicotine dependence and personal history of lung disease.

A considerable percentage of smokers (29%, corresponding to 40.5% of smokers intending to quit) was in the contemplation state, a value higher than previously reported for Switzerland [5,22,23], Germany [39] and other countries [32], but within or even below values reported for Canada [40]. Also, circa 14% of smokers (19.5% of smokers intending to quit) were in the preparation state, a value higher than previously reported for Switzerland [5] but lower than in Canada [40]. This rise in the percentage of smokers in the contemplation and preparation states can be explained by the rising public awareness in Switzerland concerning tobacco-related illness and suggest that Swiss smokers are slightly more motivated to quit than in other countries, although further improvements are still achievable. As for intention to quit, nicotine dependency was negatively related and previous quitting attempts were positively related with motivation to quit, while no significant independent relationships were found with gender, age, marital status and alcohol consumption. Overall, our results indicate that the factors that or which influence intention to quit also influence the motivation of quitters; namely, previous unsuccessful quitting attempts do not appear to de-motivate smokers from quitting. Our results also suggest that physical activity might be a good adjunct to promote quitting smoking and smoking abstinence, perhaps by improving mood and self-efficacy [41]. However, further studies are needed, as physical activity was no longer related with motivation on multivariate analysis.

This study has some limitations. First, the overall participation rate of the CoLaus study was low (41%), which might limit the generalization of the findings; however, this participation rate is similar to other epidemiological studies [42]. Further, not all smokers answered the questionnaire and significant differences were found between responders and non-responders regarding age, personal or family history of lung disease and amount of tobacco smoked (table 5). Further, comparing the CoLaus data with the data from the Swiss Health Surveys from 2002 and 2007 for the same age groups showed a lower prevalence of current smokers and a higher prevalence of former smokers in our study (table 6), although the differences were less strong when compared with data from the same canton (table 6). Hence, it is possible that our study includes more health-conscious participants, which might overestimate rates of willingness to quit and underestimate the rates of difficulty to quit. Still, in the absence of other studies, our results provide a first estimation of the willingness and motivation to quit smoking in Switzerland. For instance, the National Survey on Tobacco indicates that 34% of current smokers have been advised to quit, but no information regarding individual willingness and motivation to quit smoking was collected [43]. Also, state of change might not distinguish properly (pre)contemplators [44] and it has been suggested that individual components should be used instead [45]. Still, similar findings were obtained when using intention to quit within 30 days or within 6 months instead of the state of change, or when using overall tobacco consumption or time between waking up and first cigarette instead of HSI (not shown). Only subjects of Caucasian origin were included in this study, and inference should be done accordingly, as genetic differences regarding intention and easiness to quit smoking may exist [46]. Further, some studies [47-49] but not others [50] suggest that alcohol dependent individuals have more difficulty to quit smoking than drinkers without alcohol dependence. However, the methods of the present study did not allow us to measure adequately alcohol dependence and no clear association was found with increased alcohol consumption. Also, no information was available regarding unemployment status, a factor known to be associated with increased smoking [51,52] and decreased quitting rates [53,54], which would represent a particular target group for health promotion or smoking cessation. Finally, as Switzerland has been recently placed in stage 4 of the smoking epidemic model, a stage characterized by the peak of social awareness concerning the hazards of tobacco smoking [55], the rise in the percentage of smokers wishing to quit may simply be a reflection of this rise in public consciousness.

Table 6. comparison of smoking rates between the CoLaus study and the Swiss Health Surveys 2002-7, overall and for the Vaud canton

Conclusion

In summary, our results indicate that two thirds of Swiss smokers want to quit, but only a small fraction is in the preparation state. Nicotine dependence, previous attempts to quit, physical activity or previous history of lung disease are independently associated with difficulty and intention to quit.

Competing interests

The authors declare that they have no competing interests.

Authors' contributions

PMV and JMC analysed the data, drafted and revised the paper. GW and PV initiated the CoLaus study, monitored data collection for the whole study and revised the paper. FP and JC monitored data collection and revised the draft paper. All authors read and approved the final manuscript.

Acknowledgements

The CoLaus study was supported by research grants from GlaxoSmithKline and from the Faculty of Biology and Medicine of Lausanne, Switzerland, and is currently supported by Swiss National Science Foundation (grant no: 33CSCO-122661).

We thank Yolande Barreau, Anne-Lise Bastian, Binasa Ramic, Martine Moranville, Martine Baumer, Marcy Sagette, Jeanne Ecoffey and Sylvie Mermoud for data collection.

References

  1. World Health Organization: WHO Report on the Global Tobacco Epidemic, 2008: The MPOWER package. Geneva, Switzerland; 2008.

  2. Office Fédéral de la Santé Publique: Programme national tabac 2008-2012. Bern, Switzerland; 2008.

  3. Office Fédéral de la Santé Publique: Dossier sur la politique en matière de tabagisme dans les cantons et en Europe. Etat au 1er Janvier 2008. Bern, Switzerland; 2008.

  4. Marques-Vidal P, Cerveira J, Paccaud F, Cornuz J: Smoking trends in Switzerland, 1992-2007: a time for optimism?

    J Epidemiol Community Health 2010. PubMed Abstract | Publisher Full Text OpenURL

  5. Etter JF: Smoking prevalence, cigarette consumption and advice received from physicians: Change between 1996 and 2006 in Geneva, Switzerland.

    Addict Behav 2010, 35:355-358. PubMed Abstract | Publisher Full Text OpenURL

  6. Evolution mensuelle de la population [http://www.lausanne.ch/view.asp?docId=22884&domId=63584&language=F] webcite

  7. Firmann M, Mayor V, Marques-Vidal P, Bochud M, Pécoud A, Hayoz D, Paccaud F, Preisig M, Song KS, Yuan X, et al.: The CoLaus study: a population-based study to investigate the epidemiology and genetic determinants of cardiovascular risk factors and metabolic syndrome.

    BMC Cardiovasc Disord 2008, 8:6. PubMed Abstract | BioMed Central Full Text | PubMed Central Full Text OpenURL

  8. Section de Santé Office Fédéral de la Statistique: Enquête Suisse sur la Santé 2007. Les indices. [Swiss Health Survey 2007. Indexes]. Neuchâtel, Switzerland; 2008.

  9. Heatherton TF, Kozlowski LT, Frecker RC, Rickert W, Robinson J: Measuring the heaviness of smoking: using self-reported time to the first cigarette of the day and number of cigarettes smoked per day.

    Br J Addict 1989, 84:791-799. PubMed Abstract | Publisher Full Text OpenURL

  10. Prochaska JO, DiClemente CC: Stages of change in the modification of problem behaviors.

    Prog Behav Modif 1992, 28:183-218. PubMed Abstract OpenURL

  11. Wewers ME, Stillman FA, Hartman AM, Shopland DR: Distribution of daily smokers by stage of change: Current Population Survey results.

    Prev Med 2003, 36:710-720. PubMed Abstract | Publisher Full Text OpenURL

  12. Keller R, Willi M, Krebs H, Hornung R: Tabakmonitoring- Schweizerische Umfrage zum Tabakkonsum. Aufhör- bzw. Reduktionsbereitschaft der Raucherinnen und Raucher in der Schweiz. Zurich, Switzerland; 2004.

  13. Clerc O, Nanchen D, Cornuz J, Marques-Vidal P, Gmel G, Daeppen JB, Paccaud F, Mooser V, Waeber G, Vollenweider P, et al.: Alcohol drinking, the metabolic syndrome and diabetes in a population with high mean alcohol consumption.

    Diabet Med 2010, 27:1241-1249. PubMed Abstract | Publisher Full Text OpenURL

  14. Chaiton MO, Cohen JE, McDonald PW, Bondy SJ: The Heaviness of Smoking Index as a predictor of smoking cessation in Canada.

    Addict Behav 2007, 32:1031-1042. PubMed Abstract | Publisher Full Text OpenURL

  15. Konings E, Dubois-Arber F, Narring F, Michaud PA: Identifying adolescent drug users: results of a national survey on adolescent health in Switzerland.

    J Adolesc Health 1995, 16:240-247. PubMed Abstract | Publisher Full Text OpenURL

  16. Thyrian JR, Panagiotakos DB, Polychronopoulos E, West R, Zatonski W, John U: The relationship between smokers' motivation to quit and intensity of tobacco control at the population level: a comparison of five European countries.

    BMC Public Health 2008, 8:2. PubMed Abstract | BioMed Central Full Text | PubMed Central Full Text OpenURL

  17. Rönmark EP, Ekerljung L, Lotvall J, Torén K, Rönmark E, Lundbäck B: Large scale questionnaire survey on respiratory health in Sweden: effects of late- and non-response.

    Respir Med 2009, 103:1807-1815. PubMed Abstract | Publisher Full Text OpenURL

  18. Leatherdale ST: What modifiable factors are associated with cessation intentions among smoking youth?

    Addict Behav 2008, 33:217-223. PubMed Abstract | Publisher Full Text OpenURL

  19. Aubin HJ, Peiffer G, Stoebner-Delbarre A, Vicaut E, Jeanpetit Y, Solesse A, Bonnelye G, Thomas D: The French Observational Cohort of Usual Smokers (FOCUS) cohort: French smokers perceptions and attitudes towards smoking cessation.

    BMC Public Health 2010, 10:100. PubMed Abstract | BioMed Central Full Text | PubMed Central Full Text OpenURL

  20. Perkins KA, Scott J: Sex differences in long-term smoking cessation rates due to nicotine patch.

    Nicotine Tob Res 2008, 10:1245-1250. PubMed Abstract | Publisher Full Text OpenURL

  21. Osler M, Prescott E, Godtfredsen N, Hein HO, Schnohr P: Gender and determinants of smoking cessation: a longitudinal study.

    Prev Med 1999, 29:57-62. PubMed Abstract | Publisher Full Text OpenURL

  22. Eckert T, Junker C: Motivation for smoking cessation: what role do doctors play?

    Swiss Med Wkly 2001, 131:521-526. PubMed Abstract OpenURL

  23. Miedinger D, Chhajed PN, Karli C, Lupi GA, Leuppi JD: Respiratory symptoms and smoking behaviour in Swiss conscripts.

    Swiss Med Wkly 2006, 136:659-663. PubMed Abstract OpenURL

  24. Loumakou M, Brouskeli V, Sarafidou JO: Aiming at Tobacco Harm Reduction: a survey comparing smokers differing in readiness to quit.

    Harm Reduct J 2006, 3:13. PubMed Abstract | BioMed Central Full Text | PubMed Central Full Text OpenURL

  25. Siahpush M, McNeill A, Borland R, Fong GT: Socioeconomic variations in nicotine dependence, self-efficacy, and intention to quit across four countries: findings from the International Tobacco Control (ITC) Four Country Survey.

    Tob Control 2006, 15(Suppl 3):iii71-iii75. PubMed Abstract | Publisher Full Text | PubMed Central Full Text OpenURL

  26. Haukkala A, Laaksonen M, Uutela A: Smokers who do not want to quit--is consonant smoking related to lifestyle and socioeconomic factors?

    Scand J Public Health 2001, 29:226-232. PubMed Abstract | Publisher Full Text OpenURL

  27. Peretti-Watel P: Demain, j'arrête...Portraits statistiques des "fumeurs dissonants" [I will quit tomorrow... Statistical portrayals of "dissonant smokers"].

    Rev Epidemiol Sante Publique 2003, 51:215-226. PubMed Abstract | Publisher Full Text OpenURL

  28. Peretti-Watel P, Halfen S, Gremy I: Risk denial about smoking hazards and readiness to quit among French smokers: an exploratory study.

    Addict Behav 2007, 32:377-383. PubMed Abstract | Publisher Full Text OpenURL

  29. Yu DK, Wu KK, Abdullah AS, Chai SC, Chai SB, Chau KY, Jeong AK, Liu CY, Tam WK, Yu WH, et al.: Smoking cessation among Hong Kong Chinese smokers attending hospital as outpatients: impact of doctors' advice, successful quitting and intention to quit.

    Asia Pac J Public Health 2004, 16:115-120. PubMed Abstract | Publisher Full Text OpenURL

  30. Reichert J, Araújo AJ, Gonçalves CM, Godoy I, Chatkin JM, Sales MP, Santos SR: Smoking cessation guidelines--2008.

    J Bras Pneumol 2008, 34:845-880. PubMed Abstract | Publisher Full Text OpenURL

  31. McCaul KD, Hockemeyer JR, Johnson RJ, Zetocha K, Quinlan K, Glasgow RE: Motivation to quit using cigarettes: a review.

    Addict Behav 2006, 31:42-56. PubMed Abstract | Publisher Full Text OpenURL

  32. Hyland A, Borland R, Li Q, Yong HH, McNeill A, Fong GT, O'Connor RJ, Cummings KM: Individual-level predictors of cessation behaviours among participants in the International Tobacco Control (ITC) Four Country Survey.

    Tob Control 2006, 15(Suppl 3):iii83-iii94. PubMed Abstract | Publisher Full Text | PubMed Central Full Text OpenURL

  33. Ladwig KH, Baumert J, Lowel H, Doring A, Wichmann HE: Contemplating to quit current smoking status: differences in behavioural and psychosocial patterns in a population-based cohort of current smokers.

    Prev Med 2005, 41:134-140. PubMed Abstract | Publisher Full Text OpenURL

  34. Donze J, Ruffieux C, Cornuz J: Determinants of smoking and cessation in older women.

    Age Ageing 2007, 36:53-57. PubMed Abstract | Publisher Full Text OpenURL

  35. Yong HH, Borland R, Siahpush M: Quitting-related beliefs, intentions, and motivations of older smokers in four countries: findings from the International Tobacco Control Policy Evaluation Survey.

    Addict Behav 2005, 30:777-788. PubMed Abstract | Publisher Full Text OpenURL

  36. Tait RJ, Hulse GK, Waterreus A, Flicker L, Lautenschlager NT, Jamrozik K, Almeida OP: Effectiveness of a smoking cessation intervention in older adults.

    Addiction 2007, 102:148-155. PubMed Abstract | Publisher Full Text OpenURL

  37. Siahpush M, Borland R, Yong HH, Kin F, Sirirassamee B: Socio-economic variations in tobacco consumption, intention to quit and self-efficacy to quit among male smokers in Thailand and Malaysia: results from the International Tobacco Control-South-East Asia (ITC-SEA) survey.

    Addiction 2008, 103:502-508. PubMed Abstract | Publisher Full Text OpenURL

  38. Sohn M, Stotts NA, Benowitz N, Christopherson D, Kim KS, Jang YS, Ahn MS, Froelicher ES: Beliefs about health, smoking, and future smoking cessation among South Korean men hospitalized for cardiovascular disease.

    Heart Lung 2007, 36:339-347. PubMed Abstract | Publisher Full Text OpenURL

  39. Rüge J, Broda A, Ulbricht S, Klein G, Rumpf HJ, John U, Meyer C: Beschränkungen des Tabakrauchens am Arbeitsplatz: Rauchverhalten und die Intention zur Verhaltensanderung bei fortgesetztem Rauchen [Workplace smoking restrictions: smoking behavior and the intention to change among continuing smokers].

    Int J Public Health 2009. OpenURL

  40. Bondy SJ, Victor JC, O'Connor S, McDonald PW, Diemert LM, Cohen JE: Predictive validity and measurement issues in documenting quit intentions in population surveillance studies.

    Nicotine Tob Res 2010, 12:43-52. PubMed Abstract | Publisher Full Text OpenURL

  41. Prochaska JJ, Hall SM, Humfleet G, Muñoz RF, Reus V, Gorecki J, Hu D: Physical activity as a strategy for maintaining tobacco abstinence: a randomized trial.

    Prev Med 2008, 47:215-220. PubMed Abstract | Publisher Full Text | PubMed Central Full Text OpenURL

  42. Tolonen H, Koponen P, Aromaa A, Conti S, Graff-Iversen S, Grøtvedt L, Kanieff M, Mindel J, Natunen S, Primatesta P, et al.: Reivew of health examination surveys in Europe. Helsinki, Finland; 2008.

  43. Krebs H, Keller R, Radtke T, Hornung R: Raucherberatung in der ärztlichen und zahnmedizinischen Praxis aus Sicht der Rauchenden und ehemals Rauchenden (Befragung 2010). Zurich, Switzerland; 2010.

  44. Balmford J, Borland R, Burney S: Is contemplation a separate stage of change to precontemplation?

    Int J Behav Med 2008, 15:141-148. PubMed Abstract | Publisher Full Text OpenURL

  45. Etter JF, Sutton S: Assessing 'stage of change' in current and former smokers.

    Addiction 2002, 97:1171-1182. PubMed Abstract | Publisher Full Text OpenURL

  46. Shiffman S, Brockwell SE, Pillitteri JL, Gitchell JG: Individual differences in adoption of treatment for smoking cessation: demographic and smoking history characteristics.

    Drug Alcohol Depend 2008, 93:121-131. PubMed Abstract | Publisher Full Text OpenURL

  47. Augustson EM, Wanke KL, Rogers S, Bergen AW, Chatterjee N, Synder K, Albanes D, Taylor PR, Caporaso NE: Predictors of sustained smoking cessation: a prospective analysis of chronic smokers from the alpha-tocopherol Beta-carotene cancer prevention study.

    Am J Public Health 2008, 98:549-555. PubMed Abstract | Publisher Full Text | PubMed Central Full Text OpenURL

  48. McKee SA, Krishnan-Sarin S, Shi J, Mase T, O'Malley SS: Modeling the effect of alcohol on smoking lapse behavior.

    Psychopharmacology (Berl) 2006, 189:201-210. PubMed Abstract | Publisher Full Text | PubMed Central Full Text OpenURL

  49. Leeman RF, McKee SA, Toll BA, Krishnan-Sarin S, Cooney JL, Makuch RW, O'Malley SS: Risk factors for treatment failure in smokers: relationship to alcohol use and to lifetime history of an alcohol use disorder.

    Nicotine Tob Res 2008, 10:1793-1809. PubMed Abstract | Publisher Full Text | PubMed Central Full Text OpenURL

  50. Kahler CW, Borland R, Hyland A, McKee SA, Thompson ME, Cummings KM: Alcohol consumption and quitting smoking in the International Tobacco Control (ITC) Four Country Survey.

    Drug Alcohol Depend 2009, 100:214-220. PubMed Abstract | Publisher Full Text | PubMed Central Full Text OpenURL

  51. Moulin JJ, Labbe E, Sass C, Gerbaud L: Santé et instabilité professionnelle: résultats issus des centres d'examens de santé de l'assurance-maladie [Job insecurity, unemployment and health: results from the health examination centers of the French General Health Insurance].

    Rev Epidemiol Sante Publique 2009, 57:141-149. PubMed Abstract | Publisher Full Text OpenURL

  52. Schunck R, Rogge BG: Unemployment and its association with health-relevant actions: investigating the role of time perspective with German census data.

    Int J Public Health 2010, 55:271-278. PubMed Abstract | Publisher Full Text OpenURL

  53. Kriegbaum M, Larsen AM, Christensen U, Lund R, Osler M: Reduced probability of smoking cessation in men with increasing number of job losses and partnership breakdowns.

    J Epidemiol Community Health 2010. PubMed Abstract | Publisher Full Text OpenURL

  54. Burgess DJ, Fu SS, Noorbaloochi S, Clothier BA, Ricards J, Widome R, van RM: Employment, gender, and smoking cessation outcomes in low-income smokers using nicotine replacement therapy.

    Nicotine Tob Res 2009, 11:1439-1447. PubMed Abstract | Publisher Full Text OpenURL

  55. Lopez AD, Collishaw NE, Piha T: A descriptive model of the cigarette epidemic in developed countries.

    Tob Control 1994, 3:242-247. Publisher Full Text OpenURL

Pre-publication history

The pre-publication history for this paper can be accessed here:

http://www.biomedcentral.com/1471-2458/11/227/prepub