Tobacco use prevalence patterns
Occasional (non‐daily) snus use was very uncommon (3% in men and 1% in women) whereas occasional smoking was more common (9% and 6% in men and women, respectively). However, as daily use is typical for both snus and smoking, and as both the level of dependence and magnitude of health effects are much greater for daily users, the subsequent analyses focus on daily use.
Table 1 presents the overall patterns of daily smoking and snus use by sex and age.
Table 1Prevalence of daily tobacco use by sex and age
More women than men were current daily smokers, 19% (95% CI 17.7% to 20.3%) v
15% (95% CI 13.8% to 16.2%). Conversely, current daily use of snus was much higher in men than women, 21%
(95% CI 19.6% to 22.4%) v
2% (95% CI 1.5% to 2.5%). More women than men smoke in every age group except 65–79. Daily snus use is most common in ages 25–44, while daily smoking is most common in ages 45–64. Daily dual use, using both smoking and snus daily, was rare, with just 2% of the men and no women reporting this pattern. Absence of any daily tobacco use was more common among women than among men.
Initiation of tobacco use
The answers to questions regarding age at onset of daily tobacco use showed that among men almost all daily smoking (91%) has been initiated by age 22, while initiation of daily snus use continued throughout the age range (33% occurring after age 22). In a comparison between two birth cohorts of men (current age 22–41 and 42–61, respectively) with regard to initiation in young ages (below 23) we found a shift in patterns of initiation. In the older cohort initiation in young ages was dominated by onset of smoking, while onset of snus use was dominating in the younger cohort. The emergence of dominating snus use in young men was accompanied by decreased initiation of smoking and also by a decrease of total initiation of tobacco use in young men.
Initiation patterns were analysed also with respect to the order of initiation of daily smoking and daily snus use, respectively, as illustrated in fig 1.
Figure 1Pathways of male tobacco use (percentages in boxes based on all men ages 16–79). The left section of the figure shows the proportions of men who started daily snus use, smoking, both (and if so, in what order) or no tobacco use. (more ...)
Firstly, two main groups were identified: primary snus users (PSNU)—started daily tobacco use as snus users; and non‐primary snus users (NPSNU).
By subdivision with regard to subsequent steps in the initiation process, five final initiation categories were identified:
- Primary snus users who never started daily smoking
- Primary snus users who started secondary daily smoking (secondary smokers)
- Primary smokers (PSMO) who never started daily snus use.
- Primary smokers who started secondary daily snus use (secondary snus users).
- Never daily tobacco users (NTOB).
In 91% of the male primary snus users, the age of onset of daily snus use was lower than 23 years, whereas in the majority (66%) of the secondary snus users (category 4 above) the onset of daily snus use occurred after the age of 22 years. Further, in ages below 23, a majority (79%) of those starting daily snus use are primary snus users, while in ages 23+ the majority (83%) of those starting daily snus use are secondary snus users (a subgroup of primary smokers). These patterns suggest that secondary snus use is initiated in a context of using snus as an aid to smoking cessation.
The data shown in fig 1 demonstrate that 16% of the men started daily tobacco use as a snus user. Among these primary snus users 20% started daily smoking compared to 47% among non‐primary snus users (OR 0.28, 95% CI 0.22 to 0.36). Thus, the odds of initiating daily smoking were significantly lower for those who had started using snus than for those who had not. This association pattern remained the same (and still significant) across age groups and levels of education. Among primary smokers, 28% started secondary daily snus use and 73% did not.
The course of tobacco use
Figure 1 shows 13 different pathways with each one leading to one of four different alternatives of current tobacco use. This illustrates the characteristics of different alternatives for the course of tobacco use.
Eighty‐eight per cent of the primary smokers with secondary daily snus use (category 4) had ceased daily smoking by the time of the survey, compared to 56% among those primary smokers (category 3) who never started daily snus use (OR 5.7, 95% CI 4.0 to 8.1). Among those primary snus users who started secondary daily smoking (category 2), 74% later ceased daily smoking, 56% returned to exclusive daily snus use, and 18% had by the time of the survey quit daily snus use as well. Among primary smokers who started secondary daily snus use (category 4), only 3% had returned to exclusive daily smoking by the time of the survey. Among all ever daily smokers, the odds of still being a daily smoker at the time of the survey were significantly higher for those without a history of daily snus use (category 3) as compared to those with a history of daily snus use (categories 2 and 4) (OR 4.4, 95% CI 3.2 to 5.9). Of all the men who reported ever becoming a daily snus user (840), 26.2% (220) were no longer using snus at the time of the survey. A very small proportion (6%) of current daily smokers were initially primary snus users, while the vast majority of current smokers (94%) were primary smokers.
The overall quit rate (proportion of ever daily smokers having stopped completely) was 59% (95% CI 56% to 62%) for men and 49% (95% CI 46% to 52%) for women. Comparing men and women with a history of daily snus use, we found a quit rate of 72% (95% CI 68% to 76%) for men and 71% (95% CI 61% to 81%) for women, a non‐significant difference. Comparing men and women without a history of daily snus use, we found a quit rate of 51% (95% CI 48% to 54%) for men and 48% (95% CI 45% to 51%) for women, a non‐significant difference, whereas in each sex the quit rates differ significantly between those with and those without a history of daily snus use.
Smoking cessation practices
Ever daily smokers were asked if they had made quit attempts and, if so, when. Eighty‐eight per cent of male and 91% of female ever daily smokers answering that question indicated that they had made at least one quit attempt. Among the ex‐smokers (former daily smokers who had quit completely), 84% had quit five or more years previously, whereas among the continuing daily smokers, more than half (51%) had made an unsuccessful quit attempt within the past four years.
Those who had made a quit attempt were asked: “At your latest attempt to quit smoking, did you use an aid?” and nine options were given for possible answers.
Forty‐one per cent (458) of these men and 35% (437) of these women reported using an aid at their latest quit attempt. Usually just one aid was used, but 9% had used combinations of up to three aids.
Table 2 shows the number of quit attempts where each aid in question was used.
Table 2Use of different aids at latest quit attempt among the 895 triers reporting use of an aid
Among ever daily smokers who had tried to quit smoking (and reported on their use/non‐use of aids), 24% (254/1057) of the men and 6% (66/1193) of the women had used snus as an aid on their latest quit attempt. Corresponding figures for the sum of all NRT products were 11% (120/1057) for men and 41% (489/1193) for women. Snus was the aid most commonly used on its own and the most commonly used smoking cessation aid overall among men.
For those using the three most common cessation aids the outcome of the latest quit attempt was established in three categories with respect to smoking status at the time of the survey: continuing daily smoking (failure), ceased smoking daily and reduced to occasional smoking (partial success), and quit smoking completely (success). The proportions of these categories in men and women are presented in table 3.
Table 3Outcome of latest attempt to quit smoking, by sex and type of cessation aid used (alone or as one of two or three)
Both among men and women snus users include fewer failures (continuing daily smoking) and more successes than gum and patch users.
The increased likelihood for daily smokers to quit completely by using snus as a cessation aid is clearest in the comparison with patch use. For men the snus:patch OR for success (quitting completely) is 3.6 (95% CI 2.2 to 6.0) and for women the OR is 3.6 (95% CI 2.0 to 6.4). In the comparison between snus and gum use the OR is 1.8 (95% CI 1.2 to 2.7) for men, and for women the OR is 2.7 (95% CI 1.5 to 4.7).
When comparing the outcomes of users of a single aid, the patterns are the same as those in table 3, but the differences between the aids is slightly larger, (for example, among men, 66% of snus users quit, versus 47% of gum users and 32% of patch users). Among men the snus:patch OR for success is 4.2 (95% CI 2.1 to 8.6), and the snus:gum OR for success is 2.2 (95% CI 1.3 to 3.7). Among women the snus:patch OR for success is 3.0 (95% CI 1.4 to 6.1), and the snus:gum OR for success is 2.1 (95% CI 1.1 to 4.1).
In analyses that stratified for age and level of education (“high” defined as “college or college‐preparatory high school”), these relationships between use of snus as an aid and smoking cessation (that is, significantly higher quit rates among those using snus) were similar across levels of education and across the age range. These results suggest that it is unlikely that the higher quit rates among snus users are due to confounding with these variables. However, there could have been confounding with some other unmeasured variable (for example, motivation to quit).
Among those 168 subjects (141 men, 27 women) who had completely quit smoking after using snus as single cessation aid, 76% (128/168) were using snus daily at the time of the survey. Among those who had completely quit smoking after using an NRT product as a single cessation aid, 12% were using NRT daily at the time of the survey.
Since NRT products were available from the 1980s only, a comparison was made regarding distribution over time of quit events from 1980 and onwards. The median year for quitters with gum was 1995, for quitters with patch 1996. Among quitters with snus there was an interesting difference between men, median year 1993, and women, median year 1997. In all groups by sex and aid combinations, most ex‐smokers had quit smoking for at least three years.