Comparison of patients refusing with patients accepting unlinked anonymous HIV testing in an outpatient STD department in The Netherlands.

From 1 February 1993 to 1 February 1994 all new patients, known patients with new problems, and prostitutes attending the Outpatient Department of Sexually Transmitted Diseases (STD) of the University Hospital Rotterdam were asked to participate in unlinked anonymous human immunodeficiency virus (HIV) testing and to answer some questions. Data from the medical records of 300 patients refusing to participate were compared with self-reported data obtained from 2701 people accepting, to verify if the HIV seroprevalence among accepters could be representative for all STD department visitors. Men refusing were more often of foreign origin, had more often had more than one partner during the previous 6 months, more often attended the STD department for the first time, and more often had an STD diagnosed than men accepting. Women refusing were more often of foreign origin, had less often had more than one partner during the previous 6 months, and had more often used drugs intravenously than women accepting. Because most findings associated with refusing are also associated with being infected with HIV, the HIV seroprevalence among refusers is likely to be higher than among accepters. We therefore advise unlinked anonymous HIV testing of all patients visiting an STD department.