Table 2

Smoking habits of ever-smokers by sex and socioeconomic status (SES)

 Smoking habits by SES, and differences between men and women
SES 1SES 2SES 3SES 4SES 5
n
 Women91 34265 69448 62938 50227 511
 Men76 90353 66839 35731 96625 603
Smoking status
Ever smokers
 Women19 710 (21.6)16 354 (24.9)13 964 (28.7)12 892 (33.5)10 858 (39.5)
 Men25 591 (33.3)19 301 (36.0)15 178 (38.6)13 705 (42.9)12 504 (48.8)
Women-to-men ratio0.650.690.740.780.81
Age at which participant first started to smoke
 Women18.0 (4.1)17.9 (4.3)17.9 (4.5)17.9 (4.7)17.7 (4.9)
 Men17.1 (3.7)17.0 (3.9)16.9 (4.1)17.0 (4.5)16.9 (5.0)
Mean difference1.0 (0.9 to 1.0)1.0 (0.9 to 1.1)1.0 (0.9 to 1.1)0.9 (0.8 to 1.0)0.8 (0.6 to 0.9)
Cigarettes smoked per day
 Women15.3 (7.7)15.7 (8.0)16.1 (8.2)16.5 (8.6)17.2 (9.2)
 Men19.7 (10.5)20.0 (10.6)20.1 (10.9)20.8 (12.1)21.5 (12.9)
Mean difference−4.3 (−4.4 to −4.1)−4.2 (−4.4 to −4.0)−3.9 (−4.1 to −3.7)−4.1 (−4.4 to −3.9)−4.2 (−4.5 to −3.9)
Pack-years of smoking
 Women17.5 (13.5)17.5 (14.2)17.5 (14.6)18.0 (15.3)19.1 (16.7)
 Men23.1 (18.1)23.0 (18.6)22.7 (18.9)23.4 (20.6)25.3 (23.2)
Mean difference−4.9 (−5.2 to −4.6)−4.9 (−5.2 to −4.5)−4.7 (−5.1 to −4.3)−4.9 (−5.4 to −4.5)−6.0 (−6.5 to −5.5)
Age at which participant stopped smoking
 Women37.9 (11.4)39.0 (11.6)39.8 (11.4)40.8 (11.6)42.9 (11.4)
 Men38.9 (11.5)39.7 (11.6)40.2 (11.5)41.5 (11.7)42.8 (11.6)
Mean difference−0.2 (−0.5 to 0.0)0.0 (−0.2 to 0.3)0.2 (−0.1 to 0.5)0.1 (−0.2 to 0.4)0.6 (0.2 to 1.0)
  • Age is in years. Data are n (%) for categorical variables, and mean (SD) for continuous variables in women and men. Mean difference is the age-adjusted women-minus-men difference (95% CI). Data on age at smoking initiation, cigarettes smoked per day, pack-years of smoking and age at which participant stopped smoking are for current and previous smokers combined. SES was measured by the Townsend material deprivation score, thresholds for the five SES groups were −3.13, −1.53, 0.57 and 3.24.