Table 2. Adjusted odds ratios and 95%CIs for OSCC by tobacco smoking, alcohol drinking and tea consumption.
| Variables | Case–control comparisons | Case–case comparisons | ||||
|---|---|---|---|---|---|---|
| Controls | OSCC-UOF | OSCC-LOF | OSCC-LOF VS OSCC-UOF | |||
| n | n | OR(95%CI)a | n | OR(95%CI)a | OR(95%CI)a | |
| Tobacco smokingb | ||||||
| No | 1211 | 53 | 1.00 | 279 | 1.00 | 1.00 |
| Yes | 699 | 66 | 3.02 (1.73-5.26) | 299 | 2.27 (1.73-2.99) | 0.66 (0.35-1.26) |
| Tobacco smoking intensity (pack-years)b | ||||||
| Never | 1211 | 53 | 1.00 | 280 | 1.00 | 1.00 |
| <20 | 196 | 6 | 1.05 (0.41-2.72) | 50 | 1.43 (0.96-2.11) | 1.19 (0.43-3.30) |
| 20-40 | 241 | 27 | 3.79 (2.00-7.21) | 94 | 2.06 (1.46-2.90) | 0.48 (0.23-1.00) |
| ≥40 | 262 | 33 | 3.97 (2.12-7.44) | 154 | 3.09 (2.25-4.23) | 0.67 (0.33-1.38) |
| P-trend | <0.001 | <0.001 | 0.418 | |||
| Alcohol drinkingc | ||||||
| No | 1449 | 77 | 1.00 | 338 | 1.00 | 1.00 |
| Yes | 461 | 42 | 1.53 (0.97-2.41) | 240 | 2.42 (1.91-3.08) | 1.74 (1.04-2.92) |
| Quantity of alcohol drinking (g/d)c | ||||||
| Never | 1449 | 77 | 1.00 | 338 | 1.00 | 1.00 |
| <20 | 217 | 11 | 0.93 (0.47-1.84) | 65 | 1.52 (1.09-2.11) | 1.72 (0.82-3.61) |
| 20-60 | 139 | 14 | 1.63 (0.85-3.10) | 79 | 2.56 (1.83-3.58) | 1.79 (0.89-3.59) |
| ≥60 | 105 | 17 | 2.66 (1.43-4.95) | 96 | 4.19 (2.98-5.90) | 1.73 (0.89-3.36) |
| P-trend | 0.006 | <0.001 | 0.063 | |||
| Tea consumptiond | ||||||
| No | 1075 | 75 | 1.00 | 356 | 1.00 | 1.00 |
| Yes | 835 | 44 | 0.61 (0.40-0.93) | 222 | 0.61 (0.49-0.76) | 1.03 (0.66-1.61) |
| Duration of tea consumption (years)d | ||||||
| No | 1076 | 75 | 1.00 | 356 | 1.00 | 1.00 |
| <25 | 364 | 11 | 0.54 (0.31-0.94) | 60 | 0.49 (0.37-0.65) | 0.93 (0.52-1.69) |
| ≥25 | 470 | 33 | 0.68 (0.41-1.12) | 162 | 0.74 (0.57-0.96) | 1.10 (0.65-1.86) |
| P-trend | 0.09 | 0.002 | 0.930 | |||
| Quantity of tea consumed (ml/day)d | ||||||
| No | 1076 | 75 | 1.00 | 356 | 1.00 | 1.00 |
| <700 | 605 | 33 | 0.63 (0.40-0.99) | 166 | 0.64 (0.51-0.81) | 1.03 (0.64-1.66) |
| ≥700 | 229 | 11 | 0.56 (0.28-1.11) | 56 | 0.54 (0.38-0.76) | 1.04 (0.50-2.16) |
| P-trend | 0.09 | <0.001 | 0.930 | |||
aAdjustment for age, gender, education level, residence, BMI, family history of cancer
bAdditionally adjusted for alcohol drinking
cAdditionally adjusted for tobacco smoking
dAdditionally adjusted for tobacco smoking, alcohol drinking