Objectives Pelvic inflammatory disease (PID) generates diagnostic difficulty even for experienced doctors. Junior doctors and nurses also assess women with symptoms suggestive of PID. We aimed to determine if and how PID diagnoses vary between clinicians with different experience levels.

Methods Cross-sectional study conducted in UK sexual health clinic, nested within a Chlamydia trachomatis (CT), and Neisseria gonorrhoea diagnostic test accuracy study. Proportions and characteristics of women diagnosed clinically with PID by clinicians with varying experience were compared. Outcomes included demographics, presenting symptoms and signs and CT, and CT and/or gonococcal (GC) (CT/GC) positivity.

Results In 3804 women assessed by 36 clinicians, rates of PID, CT and GC were 4.4%, 10.5%, and 2.5%, with no differences between experienced and inexperienced clinicians (p=0.84, p=0.13 and p=0.07, respectively). 63.7% of PID diagnosed by experienced clinicians met Centers for Disease Control and Prevention (CDC) key clinical criteria versus 41.2% by inexperienced; experienced versus inexperienced OR 2.51; 95% CI 1.16 to 5.40). Proportions of CT (CT/GC)-positive PID increased with experience (5.9% (11.8%) to 31.9% (34.1%)); experienced versus inexperienced (OR 3.90; 95% CI 1.12 to 13.5). Percentages of women with CT (CT/GC) who were diagnosed with PID also rose with experience (2.2% (3.9%) to 14.2% (13.7%)), but CT prevalence in PID cases diagnosed by inexperienced clinicians (8.8%) was no greater than in all women they assessed (9.0%), suggesting poorer discriminative skills.

Conclusions Clinical diagnostic acumen for PID improves with experience. Inexperienced clinicians should focus on the presence of lower abdominal pain with pelvic tenderness and consider additional supportive symptoms, to improve specificity of their diagnoses.

Trial registration number: ISRCTN 42867448.