Table 1

Baseline characteristics at enrolment of the 6322 unvaccinated young adult women (18–32 years) included in the analysis

CharacteristicsN (%)
Sexual behaviour
 Sexual debut
  Yes5447 (86.2)
  No875 (13.8)
 Age at first sexual intercourse (years) (among sexually active)
  Mean17.3
  SD2.9
  Range4–33
  Median17
  IQR15–19
 Lifetime number of sexual partners
  0875 (13.9)
  12012 (32.0)
  2–32218 (35.3)
  4+1186 (18.9)
 Monthly frequency of sexual intercourse since the last visit (among sexually active)
  1 or less774 (14.4)
  2–41360 (25.4)
  5–91229 (22.9)
  10–131261 (23.5)
  14+738 (13.8)
Married/Living as married
 Yes3399 (53.9)
 No2910 (46.1)
Contraceptive use (among sexually active)
 Use of oral contraceptives
  Never1093 (20.3)
  Ever4289 (79.7)
 Use of injectable contraceptives
  Never2706 (50.4)
  Ever2665 (49.6)
 Use of condom
  Never2153 (39.7)
  Ever3269 (60.3)
 Use of other contraceptive method*
  Never4668 (85.9)
  Ever767 (14.1)
Number of full-term pregnancies
 02490 (39.4)
 11977 (31.3)
 21217 (19.3)
 >2638 (10.1)
Smoking behaviour
 Smoking status
  Never smoked5415 (85.8)
  Past426 (6.8)
  Current smoker469 (7.4)
 Among smokers, smoking intensity (# cigarettes/week)
  1–5343 (38.6)
  6–10142 (16.0)
  11–20202 (22.7)
  >20201 (22.6)
 Among smokers, age at smoking initiation (years)
  ≤14151 (16.9)
  15–18486 (54.4)
  ≥19257 (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.