Table 1.
Causal agent | Relative risk |
Low socio-economic class | 1.5 |
Low educational level | 2-3 |
Early age at first coitus | 2-4 |
Multiple sexual partners | 2-5 |
Early age at first pregnancy | 2-4 |
Multiparity | 2-4 |
Long term use of oral contraceptives | 1.5-2 |
History of sexually transmitted infections | 4-10 |
History of genital warts | 18 |
Cigarette smoking | 2-4 |
Diet low in folates, carotene and vitamin C | 2-3 |
Lack of routine cytological screening or prior abnormal smears | 2-6 |
HIV | 2.5 |
Immunosuppression | 5.7 |
HIV: Human immunodeficiency virus.