Screening Toxic Chemicals: How Accurate Must Tests Be?

A decision analysis framework is used to explore the value of screening tests for carcinogenicity; Whether a test lowers the social cost of screening depends on the test's sensitivity, specificity, and c~st and the social cost of misclassification (exonerating carcinogenic chemicals or condemning noncarcinogenic chemicals). The model shows lhat the best screening test need .not he either the most accurate or the least expensive.