A Critical Look at HIV-Antibody Tests: 1. How Accurate Are They?

As the AIDS epidemic spreads, many patients are asking their primary-care physicians to perform AIDS (HIV-antibody) testing, and in some settings, clinical circumstances prompt physicians to consider ordering the test. As a result, thousands of HIV-antibody tests are being requested each month by Canadian family doctors, where none were available only two years ago. Yet particular characteristics of HIV infection make these tests very unlike most blood tests, since their use carries clear risks as well as benefits. The authors review these risks and benefits in two sequential articles. In this first paper, they review the quantitative aspects of test accuracy (validity). In a sequential paper, to be published in next month's issue, they will discuss the risks and benefits of performing the test in various clinical circumstances.