Baseline characteristics of 2519* female students who did (n=954) or did not (n=1565) provide repeat postal samples a median of 16 months after recruitment
| Characteristics at baseline | % (n/N) of 1565 women who did not return follow-up samples | % (n/N) of 954 women who returned follow-up samples |
|---|---|---|
| Age <20 years | 49.1 (769/1565) | 36.9 (352/954) |
| Black ethnicity | 32.6 (505/1550) | 18.9 (180/952) |
| Smoker | 34.5 (536/1556) | 26.9 (256/952) |
| New partner in the previous year | 48.8 (509/1044) | 48.8 (465/953) |
| Age <16 at first sex | 29.7 (453/1525) | 29.3 (277/945) |
| Oral contraception | 43.7 (673/1541) | 54.5 (518/951) |
| Uses condoms | 58.3 (900/1542) | 47.5 (452/951) |
| Chlamydia trachomatis | 6.1 (96/1565) | 4.9 (47/954) |
| Previous history of C. trachomatis | 5.4 (81/1492) | 7.5 (68/908) |
| Mycoplasma genitalium | 3.5 (51/1470) | 2.9 (26/907) |
| Bacterial vaginosis | 27.8 (333/1463) | 17.1 (156/914) |
| Neisseria gonorrhoeae | 0.5 (7/1483) | 0.2 (2/914) |
*Ten of the total 2529 women did not provide adequate samples for chlamydia testing at baseline.