The purpose of this project was to assemble all the evidence on CT infection, PID, EP and TFI, to see if a consistent picture could be formed of the role of CT in causing reproductive damage. We looked at the worldwide literature on the risks of these outcomes following CT, and also at the UK evidence on CT prevalence, routinely reported PID and EP seen in GP surgeries, hospitals and sexually transmitted disease clinics, and at evidence on infertility from UK surveys.

We found a way of interpreting all this evidence which provided a single consistent set of estimates. It was confirmed that untreated CT infection posed a significant threat to reproductive health. Our findings show that screening is beneficial to the individual, but a focus on treating infections at the time they were acquired may have greater benefit.

The cost-effectiveness of the NCSP now needs to be re-assessed, using these new estimates of how much reproductive damage CT infection can cause.

This project has lead to a number of publications, including:

Price MJ, Ades AE, Soldan K, Welton NJ, Macleod J, Simms I, et al: The natural history of Chlamydia trachomatis infection in women: a multi-parameter evidence synthesis. Health Technol Asses 2016;20(22)

The study consisted of several sub-studies and a number of analyses. In order that other researchers can use our estimates in their studies, we provide the WinBUGS code, initial values and data in the form of word document text files (Office document, 123kB) and as WinBUGS system (.odc) files. These can be downloaded as a zipped file, and the .odc files must be extracted before they can be read from WinBUGS. Please refer to the full report for further details. The numbering refers to the numbered appendices in the report.