A study of serum CA-125 levels showed a predictive value of 97% for values >16 U/mL in diagnosing salpingitis. This test might therefore be useful in confirming peritoneal involvement when PID is suspected clinically.10
Another study developed a model using vaginal WBC (the single most sensitive factor at 78%), serum WBC (the single most specific factor at 88%), CRP, and ESR. The model was 100% sensitive if the diagnosis only required 1 positive test, although the specificity was only 18%. The positive predictive value was 65%. If all 4 were positive, specificity was 95%, with 29% sensitivity, a positive predictive value of 90%, and a negative predictive value of 47%. Prevalence was 60% in the group studied.11
Recommendations from others
The CDC recommends empiric treatment of women with lower abdominal or pelvic pain who are at risk for sexually transmitted diseases with uterine, adnexal, or cervical motion tenderness and no other identifiable cause.12
Clinical Evidence found no RCTs that compared empiric treatment of suspected PID with waiting for microbiological test results for guidance.13
The Agency for Healthcare Research and Quality recommends requiring the presence of lower abdominal, adnexal and cervical tenderness, without alternative diagnosis, for the diagnosis of PID. Temperature >101°F, cervical or vaginal discharge, elevated ESR, and positive gonococcal or chlamydia cultures all increase specificity of diagnosis.14
The United Kingdom’s national guideline recommends maintaining a low threshold for empirical treatment, citing a lack of definitive diagnostic criteria and potential for sequelae, but does recommend testing for gonorrhea and chlamydia.15