A multicenter randomized, controlled trial of HIV prevention counseling with a rapid HIV test or a standard HIV test (RESPECT-2) was conducted in 3 public STD clinics in Denver, Colorado; Long Beach, California; and Newark, New Jersey. Primary analyses and detailed methods are described elsewhere (13). Briefly, eligible clients were those who came to the clinics for a full diagnostic examination for sexually transmitted infections, were HIV-negative at enrollment, reported having vaginal or anal sex in the preceding 3 months, and were 15 to 39 years of age. At the initial visit, participants were counseled, examined, and tested for sexually transmitted infections and HIV infection. Outcomes were measured at 13-week intervals, scheduled 3, 6, 9, and 12 months from the date of enrollment. Before each follow-up visit, study staff mailed a reminder letter to each participant and made a reminder telephone call. When participants did not keep appointments, staff mailed additional reminder letters and made additional telephone calls to reschedule the visit as needed. Participants who were due for a study follow-up visit were screened for sexually transmitted infections and were interviewed if they visited the clinic any time from 1 week before the due date up to 12 weeks after the due date. Participants were given $25 for completing each follow-up visit. This amount was later increased to $50 in an attempt to improve retention rates.