Editor—An important fraction of all smokers are intermittent, non-daily smokers,1-3 and the proportion of intermittent smokers may even be rising.1 4Intermittent smokers are younger and have a higher educational and occupational status than daily smokers.1 4 Some intermittent smokers are either in the uptake phase of smoking, or are preparing for smoking cessation. However, intermittent smoking can also be a long term behaviour.1 2 Intermittent smokers are more likely than daily smokers to have a strong intention to quit smoking. They are also more likely to actively start the process of smoking cessation.1 5 Intermittent smokers probably also suffer less severe withdrawal symptoms during cessation attempts than do daily smokers and, therefore, have a greater potential for success.1 Intermittent smokers perceive quitting as not being very difficult.6 However, there are no studies concerning the prevalence of the desire to stop smoking among intermittent compared to daily smokers.

The public health survey in Malmö 1994 is a cross sectional study. A total of 5600 individuals born in 1913, 1923, 1933, 1943, 1953, 1963, 1968, and 1973 were randomly selected from the general Malmö population and interviewed by a postal questionnaire in the spring of 1994. In each age group, 700 participants (350 men and 350 women) were interviewed. The participation rate was 71%. The desire to stop smoking item, “Do you want to stop smoking?”, had two alternative answers, “yes” and “no”, and the item was dichotomised accordingly. The smoking item contained four alternatives: never smoked, stopped smoking, daily smoker, and intermittent (non-daily) smoker. The sex differences in daily smoking, intermittent smoking, never smoked, and stopped smoking were calculated using t tests (results only presented in text). The differences in proportions of daily and intermittent smokers that report a desire to stop smoking were also calculated witht tests (results only presented in text). The proportions of daily and intermittent smokers that express desire to stop smoking were calculated separately using logistic regression in order to analyse associations between sociodemographic variables and desire to stop smoking (table 1). The SPSS software package was used.

A total of 56.4% of all male and 59.9% of all female smokers (both daily and intermittent) had expressed a desire to stop smoking (p < 0.001). The proportion of daily smokers was 24.5% among men and 23.7% among women (p < 0.001). Men were intermittent smokers to a slightly higher extent (8.7%) than women (6.3%) (p < 0.001). Only 34.9% of the men had never smoked, while 50.3% of the women had never smoked (p < 0.001). In contrast, 31.9% of the men had stopped smoking compared to only 19.8% of the women (p < 0.001). A higher proportion (67.7%) of all daily smokers expressed a desire to stop smoking, compared to only 32.3% of all intermittent smokers (p < 0.001). Table 1 shows that the desire to stop smoking was highest among daily smokers born in 1963, odds ratio 1.9 (95% confidence interval (CI) 1.04 to 3.6), compared to daily smokers born in 1973. The desire to stop smoking then decreased significantly with age. No significant differences according to age in the desire to stop smoking were seen among the intermittent smokers. Daily smokers born in Sweden and abroad had expressed a desire to stop smoking to the same extent. In contrast, intermittent smokers born abroad had expressed a desire to stop smoking to a much higher extent than the group born in Sweden. No significant differences between the educational status groups in desire to stop smoking were observed for either daily or intermittent smokers.

Non-participation is not likely to have produced serious selection bias. There was a good concordance between the data and register census data concerning foreign origin and the general educational level of the Malmö population.7 There is also the possibility of bias from self reported data. Although self reporting of desire to stop smoking is the only conceivable way to assess desire to stop smoking, it is subjective and may even reflect a person's general perception of health. However, this fact would probably not bias the systematic differences between intermittent and daily smokers reported in this study. The proportion of all smokers that express a desire to stop smoking is very similar to the results of other studies.8-10

The results may seem surprising, given the fact that other studies have reported that some intermittent smokers may be former regular smokers in the process of smoking cessation, and that these studies also have reported a stronger intention to quit and a greater likelihood of having recently attempted to quit among intermittent smokers.1 5 However, the prevalence of pre-intentional desire to stop smoking seems to be much lower among intermittent than among daily smokers, and this finding strengthens the conclusion of other studies that a substantial fraction of all intermittent smokers are long term intermittent smokers and others are in the uptake phase of smoking. The conclusion that a higher proportion of daily smokers than intermittent smokers report a desire to stop smoking has yet another dimension. No less than 63.7% of all male and 65.4% of all female daily smokers that reported a desire to stop smoking also reported a desire to get help to stop smoking (yes/no). In contrast, the proportion that expressed a desire to get help to stop smoking was only 20.4% of male and 14.3% of female intermittent smokers that expressed a desire to stop smoking (p < 0001 when comparing daily and intermittent smokers among both men and women).

Pomerleau and Pomerleau have stressed that nicotine has a variety of effects that may be directly reinforcing, even in the absence of dependence.11 Specific benefits of smoking have been documented in cognitive and psychomotor performance.12The smoking of intermittent smokers may be motivated by these effects.

The results further support the notion that intermittent smokers are a specific group of smokers with smoking cessation characteristics that differ from the characteristics of daily smokers.