Distribution of cervical atypia risk factors by interval between menarche and age at the start of OC use or age at the FSI in young adult women followed up for 4 years
| Category | Interval between menarche and age at the start of OC use | Interval between menarche and the FSI | ||
| Interval <3 years | Interval ≥3 years | Interval <3 years | Interval ≥3 years | |
| (n=192) | (n=675) | (n=302) | (n=566) | |
| n/Mean (%/SD) | n/Mean (%/SD) | n/Mean (%/SD) | n/Mean (%/SD) | |
| Chlamydia trachomatis | 39 (20.3) | 59 (8.7) | 54 (18.0) | 44 (7.8) |
| HPV 16 | 55 (28.7) | 142 (21.1) | 97 (32.2) | 100 (17.8) |
| HPV 18 | 35 (18.2) | 83 (12.3) | 47 (15.6) | 71 (12.5) |
| HPV 16/18 | 69 (35.9) | 190 (28.2) | 115 (38.2) | 144 (25.4) |
| Smoking | ||||
| Never | 84 (43.8) | 405 (60.4) | 134 (44.8) | 356 (63.0) |
| Past smoker | 22 (11.4) | 69 (10.2) | 37 (12.4) | 54 (9.6) |
| Present smoker | 86 (44.8) | 197 (29.4) | 128 (42.8) | 155 (27.4) |
| Age at menarche | 13.4 (1.2) | 12.2 (1.1) | 13.1 (1.3) | 12.1 (1.1) |
| Age at FSI | 14.7 (1.2) | 16.3 (1.9) | 14.6 (1.2) | 16.7 (1.9) |
| Age at start of OC use | 14.9 (1.2) | 16.9 (1.7) | 15.3 (1.3) | 17.1 (1.7) |
| Lifetime number of partners | ||||
| 0 | 0 | 1 (0.2) | 0 | 1 (0.2) |
| 1 | 11 (5.7) | 119 (17.6) | 14 (4.6) | 116 (20.5) |
| 2–4 | 46 (24.0) | 230 (34.1) | 73 (24.2) | 204 (36.0) |
| 5–9 | 69 (36.0) | 163 (24.2) | 98 (32.5) | 134 (23.7) |
| >10 | 66 (34.4) | 162 (24.0) | 117 (38.7) | 111 (19.6) |
FSI, first sexual intercourse; HPV, human papillomavirus; OC, oral contraceptive.