From: Systematic review of the relation between smokeless tobacco and cancer in Europe and North America
 | ST use |  |  | RR/OR | ||||
---|---|---|---|---|---|---|---|---|
Sourcea | Typeb | Exposurec | Smoking | Sexd | Id. | Casese | Estimate (95%CI)d | Adjustment factorsf |
Cohort studies | Â | Â | Â | Â | Â | Â | Â | Â |
Lutheran Brotherhood: Kneller et al. 1991 [12] | ST | Ever | Any | M | 1 | 18 | 1.60 (0.58–4.50) | age, byr, smok |
 |  |  | Never | M | 2 | 3 | 3.80 (1.00–14.32) | age, byr |
US Veterans: Winn et al. 1982 [19] | ST | Ever | Never | Mg | 3 | NA | 1.51 (NA) | age |
CPS-II: Chao et al. 2002 [24] | ST | Current | Never | M | 4 | 8 | 1.58 (0.76–3.28) | age, asp, diet, edu, fhis, race, vit |
 |  | Former |  |  | 5 | 2 | 1.11 (0.27–4.50) |  |
 |  | Ever |  |  | 6 | 10 | 1.45 (0.75–2.80)h |  |
Norway cohorts: Boffetta et al. 2005 [26] | Snuff | Current | Any | M | 7 | 42 | 1.00 (0.71–1.42) | age, smok |
 |  | Former |  |  | 8 | 32 | 1.29 (0.87–1.91) |  |
 |  | Ever |  |  | 9 | 74 | 1.11 (0.83–1.48) |  |
Swedish construction workers: Zendehdel et al. 2008 [34] | Snuff | Ever | Any | M | 10 | 311 | 1.08 (0.96–1.22)i | age, bmi, smok |
 |  | Ever | Never | M | 11 | 76 | 1.33 (1.03–1.72)j | age, bmi |
Case-control studies | Â | Â | Â | Â | Â | Â | Â | Â |
Bjelke 1974 (USA) [52] | Chew | Use | Any | NA | 12 | NA | no association | NA |
Bjelke 1974 (Norway) [52] | Chew | Use | Any | NA | 13 | NA | association | NA |
Williams and Horm 1977 [55] | ST | Ever | Any | M | 14 | 12 | 1.31 (0.71–2.43)h | age, race, smok |
 |  |  |  | F | 15 | 2 | 1.50 (0.36–6.26) | none |
Weinberg et al. 1985 [67] | Chew | Ever | Any | M | 16 | NA | no association | none |
Hansson et al. 1994 [94] | Snuff | Use | Any | M+F | 17 | NA | 0.70 (0.47–1.06) | age, ses, sex, smok |
Ye et al. 1999 [107] | Chew | Ever | Any | M+F | 18 | 8 | 1.30 (0.54–3.12)h | none |
 | Snuff | Ever |  | M | 19 | 83 | 0.77 (0.56–1.06)h | age, alc, bmi, res, ses, smok |
 |  |  | Never | M | 20 | 11 | 0.50 (0.20–1.20) | age, alc, bmi, res, ses |
Lagergren et al. 2000 [108] | Snuff | Ever | Any | M+F | 21 | 53 | 1.20 (0.80–1.80) | age, alc, bmi, diet, edu, exer, rflx, sex, smok |