Cost Comparison of Three HIV Counseling and Testing Technologies

The current study examines and compares the economic costs of three HIV testing protocols at publicly funded HIV counseling and testing clinics. Of the approximately 2.3 million HIV antibody tests conducted in both 1997 and 1998, an average of 35 percent of HIV-positive clients and 42 percent of HIV-negative patients did not return for their test results, which can take up to two weeks with standard tests. New rapid antibody tests can be done in 30 minutes or less, and give clients preliminary or confirmed same-day results.

"Rapid HIV antibody tests have an indispensable role to play in the national effort to increase the number of clients who learn their HIV serostatus as early as possible," the researchers wrote, and receive appropriate post-test counseling. "These tests have been recognized as an important component of an overall strategy to achieve the national HIV strategic objective of reducing the annual number of new HIV infections to 20,000 by the year 2005 and have been highlighted by U.S. agencies such as the Centers for Disease Control and Prevention (CDC)."

In the United States, only two rapid tests -- both requiring a two-step protocol -- are licensed by FDA: the Single Use Diagnostic System (SUDS) for HIV-1 manufactured by Abbott/Murex and the OraQuick rapid HIV antibody test, manufactured by OraSure Technologies Inc. In the two-step process, blood specimens repeatedly reactive for HIV antibody on the rapid screening test are sent to a lab for a confirmatory Western blot test, so the client must return for a second visit to receive the confirmed result. Clients who test negative receive their results on the same day, without further testing. In the one-step rapid protocol recommended by WHO, a combination of two or three additional rapid assays is used to confirm an initial reactive result, giving the client all test results on the same day.

Rapid tests have been shown to increase the acceptability of HIV testing and to increase the number of persons who learn their HIV status. However, "no study has systematically analyzed the costs of these newer technologies compared with the standard protocol," the researchers noted. They developed a cost-analysis model to calculate the intervention costs associated with providing HIV counseling and testing (CT) services with each of the three protocols: standard CT, two-step and one-step rapid test.

All three protocols include client registration, pre-test counseling, risk assessment, discussion of testing, informed consent, and blood draw.

"The one-step protocol -- where combinations of rapid tests are used to provide a definitive HIV tests result -- was consistently the least expensive of the three protocols," the authors concluded. "In particular, the one-step rapid protocol was substantially less costly per HIV-positive person tested because it required neither follow-up clinic visits nor use of the expensive Western blot confirmatory assay."

"The comparison between the standard protocol and the two-step rapid protocol," they continued, "indicated that the standard protocol costs less per HIV-positive client who receives his or her test results, but costs more than the two-step protocol per HIV-negative client. For most publicly funded testing programs in the United States, where more than 98% of clients test negative, the two-step rapid protocol would be less expensive than the standard algorithm. This is because the lower cost of the rapid protocol for the large number of HIV-negative clients more than offsets its higher cost for the small number of HIV-positive clients."

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