Aubin et al. BMC Public Health 2010, 10:100 http://www.biomedcentral.com/1471-2458/10/100 cigar = 4 cigarettes; 1 pipe = 2 cigarettes. Level of dependence was evaluated by Fagerström Test for Nico- tine Dependence (FTND)[10]. Information was collected on any attempt to quit smoking: number of attempts and time of first attempt. The last attempt was more thoroughly described: dura- tion, role of health professionals, reasons which trig- gered the attempt, treatments used. Last, the intention for a future smoking cessation was explored: any contemplation of smoking cessation, esti- mated timeline to attempted cessation, reasons for stop- ping, planned smoking cessation treatments, and factors which would influence the decision to stop. An adapta- tion of the “Barriers to smoking cessation checklist” was used [11]. Initially, the self-administered questionnaire had been tested on 8 smokers by means of face-to-face interviews in order to ensure a good comprehension. Statistical analysis The representativeness of the sample was assessed by using the quota method[12], and computerised weight- ing was used, according to the Ranking Adjusted Statis- tics method [13], In order to reduce the bias due to non respondents to the screening mail, sociodemographic characteristics of the respondents were adjusted to the structure of the French general population aged 15 years and more [14]. Computerised weighting was therefore used on five criteria: gender (2 categories), age (5 cate- gories), socioprofessional status (8 categories), region (9 categories), and community size (5 categories). Weight- ing the sample ensured it was still representative of the national population. The underlying reason is that only a sample with the same structure as the mother popula- tion on defined criteria allows generalising the answers brought to other criteria to the total population. A descriptive analysis was performed for each wave. All analyses were conducted using SAS software, version 8.0 (SAS Institute). Results Out of 6,032 sent questionnaires, 3,932 were returned, i. e. the response rate was 66%. Of these, 43 (1%) were excluded because they were returned incomplete, and 3,889 were kept for analysis. As older and retired people were over-represented, weighting was comprised between 0.4 and 3.4, and its efficacy was 76.5%. After weighting, the sample of 3 889 individuals aged 15 years and more, was divided into 809 (21%) current smokers, 999 (26%) ex-smokers, and 2,081 (53%) never-smokers. Thus, extrapolation to the general population of France aged 15 years and more showed a smoking prevalence of 21%, i.e. approximately 10 million individuals. In order to have a better comparison of our results to a Page 4 of 8 competing French survey [6,7], we also calculated the prevalence of smoking after exclusion of subjects over 75 years of age: the prevalence increased up to 22.1%. Current smokers were predominantly young working males, with a rather low qualification. They had no increase of overweight/obesity or risk factor treatment prevalence compared to ex or never-smokers (Table 1). Smokers Ninety percent smoked regularly (at least weekly), of whom 85% smoked everyday. The vast majority (95%) were cigarettes smokers, with a mean (SD) consumption of 14.2 (9.4) cigarettes a day. Median was at 13 cigar- ettes a day. Adding regular cigars, cigarillos and pipe smokers, the mean smoking rate reached 14.7 cigarette equivalents. Mean (SD) FTND score was 3.1 (2,6). Median score was 3. In terms of duration, more than half the subjects (52%) have smoked for over 20 years, with a mean age of 16.5 years for the first cigarette (range: 5-50 years; median: 16 years). A profile of smokers was established according to the fact they smoked more or less than 13 cigarettes per day (median taken as a cut off). Smokers above the median consumption (≥ 13 daily cigarettes) were more often males (61%), and they started smoking at a younger age (15.8 vs 17.1 years-p < 0.01), but no differ- ence was observed in terms of age category, work status or duration of smoking. Last attempt of smoking cessation Sixty three percent of current smokers have made at least one attempt to stop smoking: 27% with one single attempt and 36% attempted several times. The chance of having made at least one attempt varied with age category: 46%, 70%, 64%, 62%, in age 15-24, 25-39, 40- 49, and 50+ categories, respectively. Mean (SD) number of attempts was 2.2 (1.4) in smokers who made at least Table 1 Sociodemographics and risk factors in current, ex, and never-smokers N (%) Male gender Age* Working Low qualification Body Mass Index (BMI)* BMI ≥ 25 kg/m2 Treated for a risk factor** Current smokers Ex-smokers Never-smokers 809 (21%) 999 (26%) 2081 (53%) 56% 40.0 (15.0) 69% 47% 24.2 (4.5) 36% 15% 60% 39% 53.4 (16.4) 45.2 (19.9) A 54% 48% 31% 24% 26.1 (4.7) 24.4 (4.5) 54% 39% 36% 25% * Mean (SD) ** Risk factors: hypertension, diabetes, hypercholesterolemia