Prediction of pelvic inflammatory disease among young, single, sexually active women.

OBJECTIVES: To assess prediction strategies for pelvic inflammatory disease (PID).

STUDY DESIGN: One thousand one hundred seventy women were enrolled based on a high chlamydial risk score. Incident PID over a median of 3 years was diagnosed by either histologic endometritis or Centers for Disease Control and Prevention criteria. A multivariable prediction model for PID was assessed.

RESULTS: Women enrolled using the risk score were young, single, sexually active, and often had prior sexually transmitted infections. Incident PID was common (8.6%). From 24 potential predictors, significant factors included age at first sex, gonococcal/chlamydial cervicitis, history of PID, family income, smoking, medroxyprogesterone acetate use, and sex with menses. The model correctly predicted 74% of incident PID; in validation models, correct prediction was only 69%.

CONCLUSIONS: Our data validate a modified chlamydial risk factor scoring system for prediction of PID. Additional multivariable modeling contributed little to prediction. Women identified by a threshold value on the chlamydial risk score should undergo intensive education and screening.