The potential efficiency of routine HIV testing of hospital patients--data from a CDC sentinel hospital.

St. Paul-Ramsey Medical Center is a member of the Centers for Disease Control (CDC) Sentinel Hospital Surveillance Group. The authors have modified the surveillance group's protocol in order to calculate what percentage of the human immunodeficiency virus (HIV)-infected samples identified came from persons known by them to be HIV infected. All identifiers are still unlinked from the sample before testing for HIV. After 24 months, the HIV seroprevalence was 0.96 percent and the estimated cost of identifying a "new" seropositive at this site is $4,530 to $9,060. This range is a cost estimate; a typical laboratory charge for the HIV ELISA screen, if applied to such a testing program, would considerably increase this estimate. Modifications to the protocol design that would target patients in certain demographic groups (for example, men ages 15 to 44 years) or HIV-associated diseases might improve efficiency but could miss a significant number of HIV-infected patients. The efficiency of hospital-based HIV testing would likely decline after several years of practice. Although there are significant ethical problems with programs attempting routine hospital-based HIV testing, pilot testing may merit consideration in areas where the HIV-1 seroprevalence is greater than 1 percent.