Should the qualitative serum pregnancy test be considered obsolete?

Abstract

Qualitative and quantitative serum human chorionic gonadotropin (hCG) tests are used to diagnose pregnancy. We assessed physicians' perceptions and compared turnaround times (TATs) and performance characteristics of both tests. We surveyed 1,058 physicians about their perceptions of hCG tests. Seven months of TAT data were analyzed. hCG was measured in all qualitative samples. Pregnancy status was determined by chart review. Of the physicians surveyed, 183 responded. Forty-nine percent preferred qualitative over quantitative serum tests for determining pregnancy status. Physicians were willing to wait 45 minutes for results from either test. Qualitative tests are performed faster than quantitative tests, but TATs were not significantly different when sample transport time was considered. The negative predictive value of both tests was 99.9%. Qualitative serum hCG testing could be replaced by quantitative hCG tests, but there is no clear advantage to doing so.