Screening for HIV: Can We Afford the False Positive Rate?

Abstract
We are a testing culture: we test our urine for drugs; we test our sweat for lies. It is not surprising that we should also test our blood for the acquired immunodeficiency syndrome (AIDS). But before we screen low-risk groups for antibody to the human immunodeficiency virus (HIV), we should consider what the results will mean. Tests for HIV antibody appear to be characterized by extraordinarily low false positive rates. Even so, positive initial and confirmatory tests in someone at low risk of HIV infection are by no means synonymous with infection, because of the possibility of false positive results. . . .