Background: Chlamydia trachomatis (CT) is an important cause of pelvic inflammatory disease (PID). Rates of CT testing and diagnosis have increased in England since the 1990s, especially following widespread implementation of the National Chlamydia Screening Programme in 2008. We investigated trends in PID diagnosed in both genitourinary medicine (GUM) clinics and general practice (GP) settings, during this period of increased chlamydia screening.
Methods: Rates of clinical PID among 15-44 year old women, diagnosed in GP settings, were calculated using the Clinical Practice Research Datalink (CPRD, diagnoses from a sample of primary care sites) for 2000-2011. Diagnoses were classified as ‘definite’, ‘probable’ or ‘possible’ PID. For the same period, rates of PID diagnoses in GUM among 15-44 year old women, were calculated from the KC60 statistical returns and the GUM Clinic Activity Dataset (GUMCAD). Identification of chlamydial and gonoccocal PID was possible for the GUM diagnoses. Trends were calculated using negative binomial regression.
Results: The rate of PID among 15-44 year olds was higher in GP than in GUM settings; in this age group, the rate of ‘definite/probable’ GP PID diagnoses declined while rates of all-cause GUM PID increased throughout the study period. A similar pattern was observed for the under 25s with GUM rates surpassing GP rates after 2007. Within GUM, chlamydial PID rates fell post 2008 (IRR=0.92, 95%
Conclusions: Although combined rates declined over the study period, divergent trends were seen in rates of PID diagnosed in different settings. However, the increase in GUM PID could be partly due to increases in GUM attendances. Interpreting trends in CT sequelae is complicated by diagnostic coding, multiple aetiologies and health-seeking behaviour. The likelihood of causes other than CT screening leading to changes in PID needs to be carefully assessed.