Receiver operating characteristic analysis for environmental diagnosis. A potential application to endocrine disruptor screening: in vitro estrogenicity bioassays.

The realization that certain chemicals are able to disrupt hormonal systems in humans and wildlife has challenged the way we assess risk from chemicals and led national and international agenciesto devise programsto screen chemicals for endocrine-disrupting properties. Chemicals capable of mimicking sex hormones, such as estrogens and androgens, have received the most attention, and although not yet validated, in vitro techniques to test for such properties are well developed. Receiver operating characteristic (ROC) analysis has been successfully used in the biomedical and military fields for several decades to assess the accuracy of diagnostic tests in terms of both their sensitivity and specificity. This approach is applied here to demonstrate its potential to assess how well in vitro bioassays can predict estrogenicity in vivo. Despite the limited availability of suitable data, the ROC curves obtained indicate that these bioassays are effective diagnostic tests. The potential sources of false positives and false negatives are identified and potential applications to endocrine disruptor screening programs discussed.