Table 1. Description of study group.
| Description | Controls | Oral cancer | |||
| (n = 791) | (n = 639) | ||||
| N (%) | N (%) | ||||
| Study | |||||
| ACTREC study | 332 (42.0) | 226 (35.4) | |||
| International oral cancer study | 459 (58.0) | 413 (64.6) | |||
| Gender | |||||
| Male | 510 (64.5) | 383 (59.9) | |||
| Female | 281 (35.5) | 256 (40.1) | |||
| Age groups | |||||
| < = 45 years | 333 (42.1) | 162 (25.4) | |||
| 46– 55 years | 199 (25.2) | 190 (29.7) | |||
| 56–65 years | 178 (22.5) | 195 (30.5) | |||
| >65 years | 81 (10.2) | 92 (14.4) | |||
| Years of education | |||||
| <5 years | 203 (26.8) | 271 (44.4) | |||
| 5–7 years | 326 (43.0) | 227 (37.2) | |||
| >7– 12 years | 141 (18.6) | 86 (14.1) | |||
| >12–15 years | 67 (8.8) | 23 (3.8) | |||
| >15 years | 21 (2.8) | 4 (0.7) | |||
| Tobacco use | OR (95%CI) ? | p-value | AF $ | ||
| Never tobacco | 308 (39.0) | 73 (11.5) | 1.0 | ||
| Smoking only | 150 (19.0) | 118 (18.6) | 5.23 (3.39– 8.07) | <0.0001 | 15 |
| Chewing tobacco only | 250 (31.7) | 326 (51.4) | 8.30 (5.78– 11.93) | <0.0001 | 45 |
| Both | 81 (10.3) | 117 (18.5) | 12.40 (7.80– 19.70) | <0.0001 | 17 |
| Alcohol consumption | |||||
| Never | 608 (76.9) | 468 (73.9) | 1.0 | ||
| Ever | 183 (23.1) | 165 (26.1) | 1.67 (1.25– 2.22) | 0.001 | 7 |
| Cancer Site | |||||
| Oral cavity | 613 (96.0) | ||||
| Pharynx | 26 (4.0) |
?
adjusted for age, sex, level of education and center.
$
Attributable fraction, expressed as percentage. Calculated using the formula p(ec)x (OR-1)/OR, where p(ec) is the proportion of exposed among cases.