S04.4 Evidence based approaches to preventing pelvic inflammatory disease (PID) and its sequelae

There are many challenges to preventing pelvic inflammatory disease (PID). The case definition is unclear: clinically diagnosed PID may not be confirmed by laparoscopy/endometrial biopsy/imaging. Both PID and its main cause Chlamydia trachomatis infection can be asymptomatic, and often no clear pathogen is identified. Most women (>85%) with chlamydia infection do not get PID. Finally, uptake of chlamydia screening is often low, and treatment of those infected and their sexual partners can be challenging. A 2016 Cochrane review found four trials (in 21, 686 women) which examined the effect of chlamydia screening on PID: Scholes, Ostergaard, Oakeshott, Andersen. Overall, the risk of PID was lower in women in intervention than control groups: RR 0.68, 0.49 to 0.94. But in the two trials at low risk of detection bias (Oakeshott, Andersen) the RR was 0.8, 0.55 to 1.17, compatible with no effect. Thus, although detection and treatment of chlamydia infection can reduce the risk of PID in an individual woman, the size of the effect is uncertain. It is also unclear whether chlamydia screening to prevent PID reduces rates of infertility and ectopic pregnancy. Our recent ‘Test n Treat’ trial of free rapid chlamydia tests and same day treatment in 500 sexually active, ethnically diverse teenagers, highlights the problems of persuading those at risk to get screened. Despite a 6.2% prevalence of chlamydia (and 0.6% gonorrhoea), test uptake was only 13%. Interviews suggested this was due to not feeling at risk, perceptions of stigma and little knowledge of STIs. However, £5 notes can be effective incentives, and enabled us to recruit 500 participants in 3-weeks. Cost analysis suggested incentives might be cost-effective for screening some high risk groups. We eagerly await results of the French i-Predict trial of 6-monthly chlamydia screening to reduce PID incidence over 2-years in 4000 female students.