Baseline characteristics at enrolment of the 6322 unvaccinated young adult women (18–32 years) included in the analysis
| Characteristics | N (%) |
| Sexual behaviour | |
| Sexual debut | |
| Yes | 5447 (86.2) |
| No | 875 (13.8) |
| Age at first sexual intercourse (years) (among sexually active) | |
| Mean | 17.3 |
| SD | 2.9 |
| Range | 4–33 |
| Median | 17 |
| IQR | 15–19 |
| Lifetime number of sexual partners | |
| 0 | 875 (13.9) |
| 1 | 2012 (32.0) |
| 2–3 | 2218 (35.3) |
| 4+ | 1186 (18.9) |
| Monthly frequency of sexual intercourse since the last visit (among sexually active) | |
| 1 or less | 774 (14.4) |
| 2–4 | 1360 (25.4) |
| 5–9 | 1229 (22.9) |
| 10–13 | 1261 (23.5) |
| 14+ | 738 (13.8) |
| Married/Living as married | |
| Yes | 3399 (53.9) |
| No | 2910 (46.1) |
| Contraceptive use (among sexually active) | |
| Use of oral contraceptives | |
| Never | 1093 (20.3) |
| Ever | 4289 (79.7) |
| Use of injectable contraceptives | |
| Never | 2706 (50.4) |
| Ever | 2665 (49.6) |
| Use of condom | |
| Never | 2153 (39.7) |
| Ever | 3269 (60.3) |
| Use of other contraceptive method* | |
| Never | 4668 (85.9) |
| Ever | 767 (14.1) |
| Number of full-term pregnancies | |
| 0 | 2490 (39.4) |
| 1 | 1977 (31.3) |
| 2 | 1217 (19.3) |
| >2 | 638 (10.1) |
| Smoking behaviour | |
| Smoking status | |
| Never smoked | 5415 (85.8) |
| Past | 426 (6.8) |
| Current smoker | 469 (7.4) |
| Among smokers, smoking intensity (# cigarettes/week) | |
| 1–5 | 343 (38.6) |
| 6–10 | 142 (16.0) |
| 11–20 | 202 (22.7) |
| >20 | 201 (22.6) |
| Among smokers, age at smoking initiation (years) | |
| ≤14 | 151 (16.9) |
| 15–18 | 486 (54.4) |
| ≥19 | 257 (28.7) |
| BMI at enrolment | |
| Underweight (<18.5 kg/m2) | 384 (6.1) |
| Normal (18.5 to <25 kg/m2) | 3215 (50.9) |
| Overweight (25 to <30 kg/m2) | 1604 (25.4) |
| Obese (≥30 kg/m2) | 1118 (17.7) |
*Use of other contraceptive methods (diaphragm, sponge, spermicide, intrauterine device and others).
BMI, body mass index.