Skip to main content

Advertisement

Table 4 Oropharyngeal cancer; meta-analysis results

From: Systematic review of the relation between smokeless tobacco and cancer in Europe and North America

     Heterogeneity
Type of ST (region)a Adjustments/restrictionsb Number of estimates (RR/OR ids)c Random-effects RR/OR (95% CI) χ2 I2 P2)
Any Overall data n = 41 (1, 2, 3, 6, 7, 11, 15, 16, 18, 19, 20, 21, 22, 23, 24, 25, 26, 28, 29, 30, 33, 34, 35, 38, 39, 41, 42, 46, 47, 48, 49, 51, 55, 56, 58, 60, 63, 65, 73, 74, 77) 1.79 (1.36–2.36) 335.6 88.1 < 0.001
  Smoking-adjusted n = 19 (2, 3, 6, 7, 11, 13, 18, 26, 35, 43, 48, 51, 55, 56, 58, 63, 69, 74, 77) 1.36 (1.04–1.77) 69.5 74.1 < 0.001
  Smoking and alcohol adjusted n = 10 (2, 3, 11, 51, 55, 56, 63, 69, 74, 77) 1.07 (0.84–1.37) 12.5 28.0 0.186
  Never smokers n = 9 (2, 3, 10, 12, 27, 43, 48, 59, 72) 1.72 (1.01–2.94) 15.9 49.7 0.044
  Never smokers – alcohol adjusted n = 3 (2, 3, 12) 1.87 (0.82–4.27) 0.6 0.0 0.731
Any (USA)d Overall data n = 31 (1, 2, 3, 15, 16, 18, 19, 20, 21, 22, 23, 24, 25, 26, 29, 30, 33, 34, 35, 38, 39, 41, 42, 46, 49, 51, 55, 56, 58, 65, 74) 2.16 (1.55–3.02) 275.8 89.1 < 0.001
  Smoking-adjusted n = 12 (2, 3, 13, 18, 26, 35, 43, 51, 55, 56, 58, 74) 1.65 (1.22–2.25) 33.6 67.3 < 0.001
  Smoking and alcohol adjusted n = 6 (2, 3, 51, 55, 56, 74) 1.04 (0.80–1.35) 1.8 0.0 0.875
  Never smokers n = 5 (2, 3, 27, 43, 59) 3.33 (1.76–6.32) 3.5 0.0 0.476
  Never smokers – alcohol adjusted n = 2 (2, 3) 1.58 (0.52–4.81) 0.4 0.0 0.512
Snuff (Scandinavia) Overall data n = 7 (6, 7, 11, 48, 63, 69, 77) 0.97 (0.68–1.37) 14.5 58.8 0.024
  Smoking-adjusted n = 7 (6, 7, 11, 48, 63, 69, 77) 0.97 (0.68–1.37) 14.5 58.8 0.024
  Smoking and alcohol adjusted n = 4 (11, 63, 69, 77) 1.10 (0.64–1.90) 10.7 71.9 0.014
  Never smokers n = 4 (10, 12, 48, 72) 1.01 (0.71–1.45) 2.2 0.0 0.524
  Never smokers – alcohol adjusted n = 1 (12) 2.30 (0.67–7.92) -- -- --
Published since 1990 Overall data n = 18 (1, 2, 3, 6, 7, 11, 48, 49, 51, 55, 56, 58, 60, 63, 65, 73, 74, 77) 1.28 (0.94–1.76) 81.7 79.2 < 0.001
  Smoking-adjusted n = 14 (2, 3, 6, 7, 11, 48, 51, 55, 56, 58, 63, 69, 74, 77) 1.00 (0.83–1.20) 18.5 29.8 0.139
  Smoking and alcohol adjusted n = 10 (2, 3, 11, 51, 55, 56, 63, 69, 74, 77) 1.07 (0.84–1.37) 12.5 28.0 0.186
  Never smokers n = 7 (2, 3, 10, 12, 48, 59, 72) 1.24 (0.80–1.90) 7.5 20.1 0.277
  Never smokers – alcohol adjusted n = 3 (2, 3, 12) 1.87 (0.82–4.27) 0.6 0.0 0.731
  1. a For each study/sex, the RR/OR for ST from Table 3 was included if available, otherwise that for chewing tobacco or snuff was used.
  2. b Smoking-adjusted includes estimates for smokers and non-smokers combined, adjusted for smoking if available, and estimates for never smokers otherwise.
  3. c The actual estimates included are identified by their RR/OR identification numbers as given in Table 3.
  4. d Includes estimates 24 and 25 from a study in Puerto Rico [49].
  5. CI = confidence interval; ST = smokeless tobacco; OR = odds ratio; RR = relative risk.