Rates of pelvic inflammatory disease and ectopic pregnancy in Australia, 2009-2014: Ecological analysis of hospital data

Objective To analyse yearly rates of pelvic inflammatory disease (PID) and ectopic pregnancy (EP) diagnosed in hospital settings in Australia from 2009 to 2014. Methods We calculated yearly PID and EP diagnosis rates in three states (Victoria, New South Wales, Queensland) for women aged 15-44 years using hospital admissions and emergency department (ED) attendance data, with population and live birth denominators. We stratified PID diagnoses as chlamydial-related or gonorrhoeal-related (Chlamydia trachomatis (CT)-related or Neisseria gonorrhoeae (NG)-related), acute, unspecified and chronic, and analysed variations by year, age and residential area using Poisson regression models. Results For PID, the rate of all admissions in 2014 was 63.3 per 100 000 women (95% CI 60.8 to 65.9) and of all presentations in EDs was 97.0 per 100 000 women (95% CI 93.9 to 100.2). Comparing 2014 with 2009, the rate of all PID admissions did not change, but the rate of all presentations in EDs increased (adjusted incidence rate ratio (aIRR) 1.34, 95% CI 1.24 to 1.45), and for admissions by PID category was higher for CT-related or NG-related PID (aIRR 1.73, 95% CI 1.31 to 2.28) and unspecified PID (aIRR 1.09, 95% CI 1.00 to 1.19), and lower for chronic PID (aIRR 0.84, 95% CI 0.74 to 0.95). For EP, in 2014 the rate of all admissions was 17.4 (95% CI 16.9 to 17.9) per 1000 live births and of all ED presentations was 15.6 (95% CI 15.1 to 16.1). Comparing 2014 with 2009, the rates of all EP admissions (aIRR 1.06, 95% CI 1.04 to 1.08) and rates in EDs (aIRR 1.24, 95% CI 1.18 to 1.31) were higher. Conclusions PID and EP remain important causes of hospital admissions for female STI-associated complications. Hospital EDs care for more PID cases than inpatient departments, particularly for young women. Updated primary care data are needed to better understand PID epidemiology and healthcare usage.