Table 4.
Analysis of possible risk factors for human papillomavirus (HPV) infection in monozygotic twins (n = 36)
| Factor | Category | HPV positive (%)* | P value† |
|---|---|---|---|
| Oral contraceptive use | Never (n = 29) | 14 (48·3) | 1·000 |
| Ever used (n = 7) | 4 (57·1) | ||
| Method of contraception | Condom (n = 4) | 2 (50·0) | 1·000 |
| Other methods§ (n = 31) | 15 (48·4) | ||
| Douche | 1–2 times a week (n = 24) | 10 (41·7) | 0·479 |
| ⩾ Every other day (n = 8) | 5 (62·5) | ||
| ⩽ 1–2 times a week (n = 3) | 2 (66·7) | ||
| Possibility of partner's extramarital affair | Not likely (n = 21) | 9 (42·9) | 0·532 |
| Maybe (n = 8) | 5 (62·5) | ||
| Likely (n = 3) | 2 (66·7) | ||
| History of STD‡ | No (n = 28) | 14 (50·0) | 1·000 |
| Yes (n = 2) | 1 (50·0) |
*
Both high-risk HPV, low-risk HPV, and HPV-X.
†
As determined by the χ2 test.
‡
Sexually transmitted disease not including cystitis or urethritis.
§
Including contraceptive infection, contraceptive suppository, intra-uterine loop, female sterilization, vasectomy, and rhythm method.