Oh et al. BMC Public Health 2010, 10:74 http://www.biomedcentral.com/1471-2458/10/74 Page 4 of 11 Table 1 Women in Europe Against Lung Cancer and Smoking (WELAS) Project demographics by country, weighted. All France Ireland Italy Czech Republic Sweden c2 (n = 5000) (n = 1000) (n = 1000) (n = 1000) (n = 1000) (n = 1000) p-value n % % % % % % (df = 4) Ever smoker (>100 cigarettes in life) Current smoker Age 18-24 25-34 35-44 45-54 55+ Age at last education <16 16-19 20-25 >25 (missing) Marital Status Married Divorced/Separated Widowed Never married Unmarried couple (missing) Income Well below the median Below the median Around the median Above the median Well above the median Refused to answer Friends/family smoke None Few Less than half About half or more (missing) Parents smoke No Yes 2622 1421 426 939 916 883 1836 601 2066 1683 476 (n = 174) 1979 727 605 1074 514 (n = 101) 463 1183 1386 805 165 998 991 2304 587 1094 (n = 24) 2101 2899 41.3 20.5 8.5 18.8 18.3 17.7 36.7 12.5 42.6 35.0 9.7 41.1 14.2 12.8 21.6 10.4 9.2 23.5 27.6 16.0 3.3 20.4 21.1 47.8 11.3 19.9 43.1 56.9 37.7 19.9 8.2 17.2 18.6 18.1 37.9 5.0 37.1 53.7 4.0 (n = 86) 46.3 20.5 3.5 11.2 18.5 (n = 38) 7.5 24.1 27.4 14.9 2.8 23.3 18.4 42.5 13.6 25.5 (n = 1) 41.4 58.6 49.0 23.5 11.4 22.0 19.8 16.8 30.0 13.2 52.3 29.2 5.3 (n = 27) 37.1 8.2 18.2 33.0 3.6 (n = 28) 7.7 25.3 26.5 21.9 3.5 15.1 20.1 52.2 10.3 17.4 (n = 7) 36.2 63.8 39.7 17.5 6.5 19.4 19.0 16.9 38.2 25.2 34.4 30.0 10.4 (n = 5) 52.1 7.8 11.6 25.4 3.1 (n = 5) 17.5 29.7 21.6 7.4 0.5 23.31 20.2 44.5 10.5 24.8 (n = 9) 43.2 56.9 34.3 19.2 8.3 20.1 16.0 17.9 37.7 6.0 49.8 35.4 8.9 (n = 13) 38.0 16.9 22.1 21.6 1.4 (n = 22) 8.2 19.2 40.8 14.5 0.8 16.5 16.7 45.9 13.3 24.1 (n = 4) 50.9 49.1 45.8 18.6 8.2 15.2 18.2 18.6 39.8 12.3 39.3 27.8 20.6 (n = 43) 31.9 17.5 8.9 16.6 25.1 (n = 8) 5.2 19.2 21.7 21.2 9.1 23.6 29.9 53.7 8.5 8.0 (n = 3) 43.8 56.2 <0.0001 0.0094 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 before the age of 14. The Czech Republic had the lowest percentage of young initiators with 13.7% starting between the ages of 14 and 15 and 1.4% starting younger than 14 years old. The highest percentage of women began smoking between the ages of 16 and 17 in all countries, except Sweden (Table 4). Overall, those who reported currently having lower income had a higher average age of smoking initiation. Average age at initiation did not vary significantly by education in the combined analysis, but did vary significantly in France and Sweden. Women in the younger age cohorts generally began smoking at a younger age than women in older age cohorts (Table 5). Linear regression analysis showed that, after controlling for reasons for starting smoking, age at initiation was significantly earlier among Swedish women (b -0.72, p = 0.02) than among French women, and significantly later among women from the Czech Republic (b 1.79, p < 0.0001) (Table 6). Women who started smoking because their friends smoked or to look ‘cool’ were more likely