Table 1.
Baseline characteristics
| Intervention group, period 1 (N=229) | Intervention group, period 2 (N=86) | Control group, period 1 (N=161) | Control group, period 2 (N=157) | |
|---|---|---|---|---|
| Age, years | ||||
| Mean | 23·2 (6·0) | 21·4 (4·8) | 22·2 (4·4) | 22·9 (5·8) |
| Methods of contraception used | ||||
| Combined hormonal contraceptive (pill, patch, or ring) | 114 (49·8%) | 41 (47·7%) | 99 (61·5%) | 94 (59·9%) |
| Progestogen-only pill | 39 (17·0%) | 19 (22·1%) | 35 (21·7%) | 32 (20·4%) |
| Male condom | 189 (82·5%) | 66 (76·7%) | 117 (72·7%) | 135 (86·0%) |
| Progestogen-only injectable | 14 (6·1%) | 6 (7·0%) | 10 (6·2%) | 18 (11·5%) |
| Progestogen-only implant | 29 (12·7%) | 10 (11·6%) | 23 (14·3%) | 19 (12·1%) |
| Copper-bearing intrauterine device | 6 (2·6%) | 0 | 4 (2·5%) | 4 (2·5%) |
| Levonorgestrel-releasing intrauterine system | 0 | 1 (1·2%) | 4 (2·5%) | 2 (1·3%) |
| Withdrawal method | 65 (28·4%) | 28 (32·6%) | 52 (32·3%) | 67 (42·7%) |
| Other methods* | 10 (4·4%) | 6 (7·0%) | 7 (4·3%) | 9 (5·7%) |
| Never used any method | 8 (3·5%) | 4 (4·7%) | 10 (6·2%) | 2 (1·3%) |
| Sexual and reproductive history | ||||
| Previous birth | 30 (13·1%) | 5 (5·8%) | 7 (4·3%) | 13 (8·3%) |
| Previous termination | 38 (16·6%) | 6 (7·0%) | 22 (13·7%) | 27 (17·2%) |
| Previous miscarriage | 17 (7·4%) | 5 (5·8%) | 10 (6·2%) | 6 (3·8%) |
| Current sexual relationship | 176 (76·9%) | 55 (64·0%) | 104 (64·6%) | 111 (70·7%) |
| First time use of emergency contraception | 52 (22·7%) | 22 (25·6%) | 28 (17·4%) | 32 (20·4%) |
| Number of times emergency contraception used in past 12 months | ||||
| Mean | 1·4 (1·4) | 1·5 (1·5) | 1·5 (1·2) | 1·7 (2·0) |
| Median | 1·0 (0·0–2·0) | 1·0 (1·0–2·0) | 1·0 (1·0–2·0) | 1·0 (1·0–2·0) |
| Minimum, maximum | 0·0–8·0 | 0·0–9·0 | 0·0–6·0 | 0·0–20·0 |
| Ethnic background | ||||
| White | 157 (68·6%) | 60 (69·8%) | 98 (60·9%) | 114 (72·6%) |
| Asian or Asian British | 21 (9·2%) | 6 (7·0%) | 8 (5·0%) | 21 (13·4%) |
| Black or Black British | 29 (12·7%) | 12 (14·0%) | 36 (22·4%) | 15 (9·6%) |
| Mixed or other | 19 (8·3%) | 6 (7·0%) | 17 (10·6%) | 6 (3·8%) |
| Not specified | 3 (1·3%) | 2 (2·3%) | 2 (1·2%) | 1 (0·6%) |
Data are mean (SD), N (%), or median (25th, 75th percentile). N is the number of women recruited. The proportion of women with previous history of ectopic pregnancy was less than 1% in all groups.
*
Other methods of protection were female condom, cap or diaphragm, vasectomy, fertility awareness, and emergency contraception.