The National Chlamydia Screening Programme (NCSP) offers free chlamydia testing to all young women (including trans and non-binary people assigned female at birth) aged 15-24 years old in England. By diagnosing and treating more chlamydia infections, the NCSP aims to prevent complications from untreated chlamydia in young women. Complications can include persistent infections of the womb, fallopian tubes (tubes connecting ovaries to the womb), or ovaries; pregnancy in the fallopian tube; and infertility. Men (and trans and non-binary people assigned male at birth) with untreated chlamydia can sometimes experience epididymitis (persistent infection in the testicles). To evaluate the success of the NCSP, we need to know how many young people are being diagnosed with conditions associated with untreated chlamydia each year. This study will use CPRD Aurum data to monitor age-specific rates of conditions linked to untreated chlamydia infection between 2010 and 2023. This will allow us to see if diagnoses of these conditions among young women have been increasing, decreasing, or staying the same during this period, and will help us to characterise groups of people most likely to experience complications from chlamydia. We will also look at diagnoses of chlamydia-associated epididymitis in young men to monitor any potential negative impacts of a recent change in NCSP policy to focus on testing young women only. These insights will inform the evaluation and improvement of the NCSP, benefiting those most at risk of chlamydia and associated complications.
The National Chlamydia Screening Programme (NCSP) offers free asymptomatic chlamydia screening to all young women (including trans and non-binary people assigned female at birth) aged 15-24 years old in England. The NCSP aims to prevent sequelae from untreated chlamydia in young women including pelvic inflammatory disease, ectopic pregnancy, and tubal factor infertility. Untreated chlamydia in men (and trans and non-binary people assigned male at birth) can sometimes lead to epididymitis.
This study will focus upon 15- to 44-year-olds resident in England between 2010 and 2023. It will use CPRD Aurum data to determine trends in chlamydia and chlamydia-associated sequelae diagnoses within CPRD clinics. Read codes that denote primary or non-primary diagnosis of chlamydia and/or acute or chronic PID/EP/TFI/epididymitis will be used to include patients within CPRD Aurum. HES data will provide further information on patient admissions and outpatient care related to the outcomes of interest. Diagnoses recorded in HES will be selected using international classification of diseases (ICD-10) codes.
Diagnoses of the outcomes of interest will be presented as total numbers and diagnosis rates per 100,000 person-years for GP settings and diagnosis rates per 100,000 population for hospital inpatient episodes. This study may contribute to the evaluation of the NCSP against its aim of reducing the burden of chlamydia-associated sequelae in women and identify any inequities between ethnic and socio-economic groups. We will also look at diagnoses of chlamydia-associated epididymitis in young men to monitor any potential negative impacts of the recommendation to screen young women only.
Number and rate (per 100,000 person-years) of diagnoses of: Chlamydia; Pelvic-inflammatory disease (PID); Epididymitis; Ectopic pregnancy (EP); Tubal factor infertility (TFI)
Katherine Soldan - Chief Investigator - UK Health Security Agency (UKHSA)
Jessica I’Anson (née Edney) - Corresponding Applicant - UK Health Security Agency (UKHSA)
Grahame Davis - Collaborator - UK Health Security Agency (UKHSA)
Miranda Ferguson - Collaborator - UK Health Security Agency (UKHSA)
HES Accident and Emergency;HES Admitted Patient Care;HES Outpatient;Patient Level Index of Multiple Deprivation;CPRD Aurum Ethnicity Record