Table 1 Characteristics of study participants by smoking status reported at recruitment

From: Heterogeneous relationships of squamous and basal cell carcinomas of the skin with smoking: the UK Million Women Study and meta-analysis of prospective studies

  Never-smoker Ex-smoker Current smoker
  N = 624,422 N = 346,657 N = 252,547
  Characteristics reported at recruitment
   Age, years 56.3 (4.7) 56.1 (4.6) 55.3 (4.3)
   Socio-economic status, highest third 38.0 (235,471) 33.3 (114,536) 22.6 (56,592)
   Height, cm 162.1 (6.6) 162.4 (6.6) 161.6 (6.7)
   Body mass index, kg/m2 26.2 (4.6) 26.7 (4.8) 25.6 (4.5)
   Any strenuous exercise 55.0 (333,709) 53.1 (178,715) 40.2 (95,943)
   More than 7 units of alcohol per week 14.4 (89,725) 25.9 (89,340) 23.7 (59,010)
 Characteristics reported at resurveys
   Red hair when aged 10 yearsa 4.7 (16,142) 4.9 (8893) 5.1 (4773)
   Blue eyesb 39.0 (113,585) 38.6 (58,620) 39.1 (29,072)
   More freckles than averageb 12.7 (33,944) 12.7 (17,716) 11.0 (7,252)
   More moles than averageb 13.4 (32,961) 13.1 (16,716) 12.6 (7,511)
   Burn easilyb 42.3 (122,417) 41.9 (63,344) 36.5 (26,954)
   Tan easilyb 41.5 (120,212) 44.4 (67,229) 48.6 (35,913)
   >5 holidays in sunny places in the past 5 yearsb 24.5 (68,411) 27.4 (39,934) 24.2 (17,108)
   Ever regularly used a sunbedb 6.7 (17,676) 10.8 (14,734) 10.5 (6899)
Follow-up from recruitment
  Average years of follow-up per woman 14.6 (3.7) 14.4 (3.9) 13.9 (4.2)
  Number developing an incident BCC 26,996 14,312 7358
  Number developing an incident SCC 3509 1857 1333
  1. Data are percentage of women (n) or mean (SD) unless otherwise specified.
  2. BCC basal cell carcinoma, SCC squamous cell carcinoma.
  3. aReported at mean 7.8 years after recruitment by 619,521 women.
  4. bReported at mean 12.5 years after recruitment by 531,066 women