Table 1 Prevalence of sociodemographics, sexual initiation, age of initiation and contraceptive use of participants
|  | Boys (n = 2408, 53.6%) % (n) | Girls (n = 2071, 46.1%) % (n) |
|---|---|---|
Age | Missing n = 0 | Missing n = 0 |
 15 years | 43.8 (1055) | 44.3 (918) |
 16 years | 34.9 (841) | 36.1 (747) |
 17 years | 18.2 (432) | 17.0 (353) |
 18 years | 3.1 (74) | 2.6 (53) |
Social Class (SES) | Missing n = 421 | Missing n = 280 |
 Low | 11.9 (286) | 12.7 (264) |
 Middle | 32.7 (787) | 32.0 (663) |
 High | 38.0 (914) | 41.7 (864) |
Family affluence (FAS) | Missing n = 274 | Missing n = 136 |
 Low | 9.2 (221) | 10.0 (207) |
 Middle | 39.2 (945) | 36.5 (756) |
 High | 40.2 (968) | 46.9 (972) |
Urban/Rural status | Missing n = 0 | Missing n = 0 |
 Urban | 61.2 (1474) | 66.8 (1383) |
 Rural | 38.8 (934) | 33.2 (688) |
Traveller status | Missing n = 30 | Missing n = 35 |
 Traveller | 1.6 (38) | 1.1 (23) |
 Non-traveller | 97.2 (2340) | 97.2 (2013) |
Disability/Chronic illness (D/CI) | Missing n = 51 | Missing n = 39 |
 D/CI | 21.0 (506) | 19.8 (410) |
 No D/CI | 76.9 (1851) | 78.3 (1622) |
Household composition | Missing n = 13 | Missing n = 13 |
 Living with both parents | 74.0 (1781) | 74.4 (1541) |
 Not living with both parents | 25.5 (613) | 25.0 (517) |
Sexual intercourse | Missing n = 257 | Missing n = 148 |
 Yes | 25.7 (619) | 21.2 (439) |
 No | 63.6 (1532) | 71.7 (1484) |
Age of initiation | Boys (n = 619) % (n) Missing n = 47 | Girls (n = 439) % (n) Missing n = 12 |
 11 years or younger | 11.1 (69) | 4.1 (18) |
 12 years | 3.9 (24) | 3.2 (14) |
 13 years | 7.8 (48) | 6.2 (27) |
 14 years | 18.3 (113) | 20.7 (91) |
 15 years | 27.3 (169) | 34.2 (150) |
 16 years | 18.9 (117) | 23.0 (101) |
 17 years or older | 5.2 (32) | 5.9 (26) |
Early sexual initiation | Missing n = 196 | Missing n = 139 |
Early sexual initiation (ages 14–15) | 45.6 (282) | 54.9 (241) |
Very early sexual initiation (aged < 14) | 22.8 (141) | 13.4 (59) |
Contraception at last intercoursea | ||
 Condom | 79.0 (489) | 80.0 (351) |
 Pill | 19.4 (120) | 26.9 (118) |
 Withdrawal | 14.5 (90) | 14.6 (64) |
 No method | 10.5 (60) | 6.8 (27) |