Probability of vaginal foreign body in girls with genital complaints
J. E. Paradise and E. D. Willis
We used Bayes' theorem to evaluate the probability of vaginal foreign
bodies in girls with genital complaints. The prevalence of vaginal foreign
bodies in outpatient girls under 13 years of age with gynecologic disorders
was found to be 4%. Review of the charts of 17 pre-menarcheal girls who had
foreign bodies on 19 occasions and of 28 girls with infectious or
nonspecific vaginitis demonstrated that patients with foreign bodies
reported vaginal bleeding more frequently than discharge (14 and two of 15
symptomatic cases, respectively), while in contrast, patients with
infectious or nonspecific vaginitis reported vaginal discharge more often
than bleeding (23 and five of 28 symptomatic controls, respectively).
Bayes' theorem indicates that, in populations resembling the one we
studied, approximately 18% of preteenage girls with vaginal bleeding with
or without discharge and 50% of those with bleeding and no discharge will
prove to have vaginal foreign bodies.
