Objectives: The clinical diagnosis of Pelvic Inflammatory Disease (PID) is subjective. Our aim was to determine if the pattern of diagnosis of PID among experienced clinicians varied compared to the diagnosis of genital warts.
Methods: We conducted a retrospective, study of 325 PID diagnoses made by experienced clinicians at Melbourne Sexual Health Centre (2002 to 2006) where doctors saw 21,785 unselected female patients in a walk in service. We compared the proportion of female patients diagnosed with PID and genital warts between doctors, then compared doctors above (high diagnosing) and below (low diagnosing) the mean rate of PID diagnosis.
Results: There were significant and clinically important differences in the proportion of women diagnosed with PID (0% to 5.7%) across 23 doctors investigated. Estimated standard deviation in the frequency of PID diagnosis (logit scale) was 1.26 (95% confidence interval(CI): 0.81 to 1.95), approximately four times larger than for warts. Patients seen by high (N=4,673) and low (N=16,787) diagnosing doctors had similar epidemiological risk profiles suggesting true distribution of PID cases across doctors was similar (P>0.13). Women diagnosed with PID by high diagnosing doctors, compared to low diagnosing doctors, were younger (Odds ratio 1.7, 95% CI: 1.1-2.8P=0.013) but otherwise had similar epidemiological and clinical features.
Conclusions: Differences in diagnostic rates for PID between doctors are substantial and may be due to PID cases being missed by some doctors.