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 for tubal disease with Chlamydia trachomatis antibody titers and hysterosalpingography (HSG), either singly or together. Design: Historical prospective chart review Setting: The Colorado Kaiser Permanente Reproductive Endocrinology Clinic. Patients: All 703 infertility patients who 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 Outcome Measure: Sensitivity, negative predictive value, and false-positive rate were the test characteristics of interest. Tubal disease was identified by laparoscopy. Results: For HSG testing, the sensitivity was 78% and the negative predictive value was 85%. For C. trachomatis titers, the sensitivity was also 78% and the negative predictive value was 82%. Ninety-five percent confidence intervals for sensitivity and negative predictive value overlapped, indicating that there was no significant difference. However, false-negative rates were the same for the two tests, but false-positive rates were lowest for HSG and series testing. Conclusions: To minimize false-positive tests and thus, to minimize unnecessary laparoscopies, HSG testing either alone or combined with the C. trachomatis antibody titer as series tests yielded a significantly lower false-positive rate. In our study group, if both tests were 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 testing sequences ace needed to determine if C. trachomatis antibody titers in series with HSG would be more cost effective than HSG alone in detecting tubal disease.