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

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].

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.

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.