Table 3. Main results of the pooled data in the meta-analysis.
| TT vs CC | (TT+CT) vs CC | TT vs (CT+CC) | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| No. (cases/controls) | OR (95%CI) | P | P (Q-test) | I2 | OR (95%CI) | P | P (Q-test) | I2 | OR (95%CI) | P | P (Q-test) | I2 | |
| Total | 6354/7944 | 1.16 (0.93-1.45) | 0.187 | 0.001 | 54.5% | 1.05 (0.90-1.21) | 0.540 | 0.000 | 68.7% | 1.14 (0.93-1.38) | 0.201 | 0.006 | 48.9% |
| Ethnicity | |||||||||||||
| Caucasian | 1265/1545 | 0.95 (0.72-1.26) | 0.742 | 0.860 | 0.0% | 1.05 (0.81-1.38) | 0.702 | 0.013 | 60.7% | 0.92 (0.71-1.20) | 0.533 | 0.511 | 0.0% |
| Mixed | 996/1968 | 1.41 (0.99-1.99) | 0.054 | 0.489 | 0.0% | 1.06 (0.85-1.33) | 0.597 | 0.143 | 37.5% | 1.38 (0.99-1.92) | 0.056 | 0.415 | 0.2% |
| Asian | 4093/4431 | 1.24 (0.80-1.91) | 0.331 | 0.000 | 80.3% | 1.02 (0.78-1.34) | 0.878 | 0.000 | 82.7% | 1.21 (0.86-1.70) | 0.279 | 0.001 | 73.1% |
| Source of control | |||||||||||||
| PB | 5225/6252 | 1.24 (0.94-1.63) | 0.121 | 0.001 | 59.0% | 1.10 (0.92-1.32) | 0.280 | 0.000 | 72.6% | 1.21 (0.97-1.51) | 0.086 | 0.019 | 46.4% |
| HB | 1129/1692 | 0.88 (0.66-1.17) | 0.377 | 0.392 | 2.5% | 0.92 (0.71-1.19) | 0.512 | 0.084 | 51.3% | 0.91 (0.63-1.34) | 0.646 | 0.181 | 36.1% |
| Sample size | |||||||||||||
| <500 | 1400/1881 | 1.28 (0.97-1.68) | 0.083 | 0.794 | 0.0% | 1.07 (0.83-1.38) | 0.613 | 0.001 | 62.2% | 1.24 (0.95-1.60) | 0.111 | 0.637 | 0.0% |
| ≧500 | 4954/6063 | 1.09 (0.76-1.55) | 0.641 | 0.000 | 80.6% | 1.03 (0.85-1.23) | 0.785 | 0.000 | 77.1% | 1.08 (0.80-1.45) | 0.630 | 0.000 | 76.5% |
| Smoking status | |||||||||||||
| Never-smoking | 606/919 | 0.79 (0.45-1.37) | 0.394 | 0.635 | 0.0% | 0.90 (0.71-1.14) | 0.376 | 0.605 | 0.0% | 0.81 (0.52-1.27) | 0.362 | 0.967 | 0.0% |
| Ever-smoking | 1223/1013 | 0.73 (0.49-1.10) | 0.134 | 0.018 | 82.1% | 1.24 (0.59-2.58) | 0.573 | 0.000 | 94.2% | 0.86 (0.62-1.21) | 0.392 | 0.091 | 58.3% |
| Drinking status | |||||||||||||
| Light-drinking | 201/474 | 0.78 (0.32-1.90) | 0.588 | 0.455 | 0.0% | 1.05 (0.75-1.46) | 0.795 | 0.431 | 0.0% | 0.99 (0.56-1.73) | 0.961 | 0.717 | 0.0% |
| Heavy-drinking | 409/519 | 3.11 (1.52-3.02) | 0.002 | 0.832 | 0.0% | 1.94 (0.88-4.27) | 0.099 | 0.001 | 82.1% | 1.62 (0.46-5.73) | 0.457 | 0.001 | 86.0% |
| Tumor type | |||||||||||||
| Oral cavity | 1298/1406 | 1.03 (0.66-1.61) | 0.883 | 0.099 | 43.8% | 0.99 (0.67-1.46) | 0.950 | 0.000 | 78.8% | 0.99 (0.67-1.45) | 0.939 | 0.168 | 34.0% |
| Combined | 1653/2667 | 0.97 (0.74-1.28) | 0.830 | 0.293 | 17.9% | 0.95 (0.79-1.15) | 0.613 | 0.079 | 45.0% | 0.97 (0.73-1.29) | 0.827 | 0.191 | 31.0% |
| Larynx | 338/650 | 1.82 (0.51-6.44) | 0.353 | 0.007 | 86.1% | 1.37 (0.63-3.00) | 0.432 | 0.006 | 86.8% | 1.64 (0.64-4.17) | 0.302 | 0.033 | 77.9% |
| Thyroid | 2554/2669 | 1.11 (0.92-1.32) | 0.275 | 0.416 | 0.0% | 1.28 (0.89-1.84) | 0.185 | 0.020 | 65.8% | 1.16 (0.99-1.37) | 0.063 | 0.457 | 0.0% |
| Nasopharynx | 511/552 | 1.15 (0.68-1.94) | 0.601 | — | — | 0.99 (0.78-1.27) | 0.958 | — | — | 1.16 (0.70-1.94) | 0.566 | — | — |
PB: population-based; HB: hospital-based
Heavy-drinking: >46 g ethanol/week