Researchers recruited 1,974 boys and 1,820 girls in year 10 (14-15 years old) from 24 mixed sex, state secondary schools in south west England.
Trained teachers gave pupils in 12 schools a single lesson on emergency contraception (intervention group). The pupils were actively involved during the lesson. Pupils in the other 12 schools did not receive the lesson until after the study (control group).
At six months, the proportion of pupils knowing the correct time limits for hormonal emergency contraception (72 hours) and for using the uterine device as emergency contraception (five days) was significantly higher in the intervention group than in the control group.
The lesson did not increase pupils sexual activity or use of emergency contraception. This is important, given the ongoing debate on the effects of sex education and the argument that promoting the use of contraception encourages sexual activity, say the authors.
The change in the pupils knowledge may not translate to a change in behaviour, as so many other factors undoubtedly play a role. However, educating teenagers on the time limits for use of emergency contraception after unprotected sex is more likely to have an impact on behaviour than, say, encouragement to use a condom, they conclude.