CHLAMYDIA-TRACHOMATIS ANTIBODY-TITERS AND HYSTEROSALPINGOGRAPHY IN PREDICTING TUBAL DISEASE IN INFERTILITY PATIENTS

Objective: To determine if the number of diagnostic laparoscopies done on women without tubal adhesive disease could be reduced by testing f or tubal disease with Chlamydia trachomatis antibody titers and hyster osalpingography (HSG), either singly or together. Design: Historical p rospective chart review Setting: The Colorado Kaiser Permanente Reprod uctive Endocrinology Clinic. Patients: All 703 infertility patients wh o had C. trachomatis antibody titers done from March 2, 1988 to April 30, 1992. The final study group was comprised of 218 patients who had antibody titers, HSG, and laparoscopy. Interventions: None. Main Outco me Measure: Sensitivity, negative predictive value, and false-positive rate were the test characteristics of interest. Tubal disease was ide ntified by laparoscopy. Results: For HSG testing, the sensitivity was 78% and the negative predictive value was 85%. For C. trachomatis tite rs, the sensitivity was also 78% and the negative predictive value was 82%. Ninety-five percent confidence intervals for sensitivity and neg ative predictive value overlapped, indicating that there was no signif icant difference. However, false-negative rates were the same for the two tests, but false-positive rates were lowest for HSG and series tes ting. Conclusions: To minimize false-positive tests and thus, to minim ize unnecessary laparoscopies, HSG testing either alone or combined wi th the C. trachomatis antibody titer as series tests yielded a signifi cantly lower false-positive rate. In our study group, if both tests we re negative, tubal disease was identified on laparoscopy in only 5% of cases. Choice of most cost-effective test sequence will depend on who bears the cost. Further studies of cost-benefit using well-defined te sting sequences ace needed to determine if C. trachomatis antibody tit ers in series with HSG would be more cost effective than HSG alone in detecting tubal disease.