Comparison of point-of-care rapid HIV testing in three clinical venues

Abstract

Rapid HIV testing with same-visit results should increase the number of individuals who know they are HIV infected. We assessed the acceptability and feasibility of point-of-care rapid testing in three public venues, a sexually transmitted disease clinic, a county jail, and an emergency department. Over 98% of all participants received their results, and 82% of newly identified HIV-positive participants entered care. Point-of-care rapid testing was feasible, acceptable, and may improve entry into care. The 1–2 week turnaround time for conventional HIV testing has been a barrier to voluntary screening and patient receipt of results. Rapid HIV tests create opportunities to expand testing venues and provide same-visit results. To assess patient acceptance, feasibility of point-of-care testing, and impact on entry into care, we studied rapid HIV testing at the CORE Center Sexually Transmitted Disease (STD) Clinic [1]. In this report, we compare that experience with rapid HIV testing in two other high-prevalence venues, Cook County Jail's female intake area, which processes 15 000 women detainees per year (50% released within 36 h), and Stroger (Cook County) Hospital's Adult Emergency Department (ED), which has approximately 120 000 visits per year. Individuals aged 18 years and older were eligible if they spoke English or Spanish, were not known to be HIV infected, had not been tested for HIV within 3 months, and evidenced mental stability to receive same-visit HIV results. Participants provided written informed consent for the research protocol and for HIV testing. The rapid HIV test used was the SUDS (Abbott/Murex, Norcross, GA, USA) assay, the only US Food and Drug Administration-approved rapid HIV test available at the time. Details of the procedures are described elsewhere [1]. In brief, three health educators offered testing to eligible participants, obtained consent, collected blood, performed the test, provided participants with negative or preliminary positive results [2], and scheduled newly diagnosed HIV-infected participants for follow-up at the CORE Center HIV clinic within 2 weeks. All SUDS tests were supplemented with a conventional enzyme immunoassay. A Western blot test was performed on repeatedly reactive SUDS or enzyme immunoassay reactive tests. The availability of the SUDS test determined the study duration at each site. The logistics at each site affected the timing of participant recruitment. In the STD clinic, patient flow was re-arranged to allow pretest counseling and phlebotomy before a provider saw the patient [1]. In the jail female intake area, the study staff approached the detainees in a corner of a large room, in open view of security officers, before jail medical screening. Detainees with reactive SUDS tests were told the results in a confidential area. In the ED, study staff approached eligible patients who were not in a critical condition, after ED registration or at the bedside. Computer records and medical charts were reviewed within 24 h of the first clinic appointment and at 6 months. Outreach investigation was initiated for any HIV-positive participant who failed to keep the initial appointment. Retention into care was defined as two or more visits within the 6 months. Rapid HIV testing was accepted by 29–69% of participants. Although the STD clinic had the highest acceptance rate (Table 1), point-of-care testing was feasible at all three test venues. Ineligibility, 20–30%, mostly resulted from claims of recent HIV testing. Of the ineligible individuals, those at the jail and ED were more likely than those in the STD clinic (8.4, 8.2, and 3.3%, respectively) to be refused for psychiatric or substance abuse reasons.Table 1: Comparison of test acceptance, patient characteristics, and results at three rapid HIV test sites.HIV infection rates were 0.9–2.8% (Table 1). All participants with reactive rapid tests and over 98% of the others received results within 2 h. The demographics of the HIV-positive patients were similar to the populations tested at each site. More than 75% of positive tests were in 25–44 year olds, and 46–78% were in heteorosexuals who reported no risk factors. Overall, 82% of participants entered into medical care; the majority had initial CD4 T-cell counts of less than 350 cells/mm3. In Chicago's busiest ED, the rapid test process was logistically feasible and surprisingly smooth. Despite having the lowest participant acceptance (29%), the large ED provided the greatest number of newly diagnosed cases. Based on a subsequent study in our ED in which the acceptance of rapid testing was 60% [3], the potential explanations for the 29% acceptance rate included interpersonal skills of the different study staff, a lack of bilingual study staff, and the inclusion of older participants (up to age 60 years) in the present study. The jail female intake provided a confined audience, but less than half of those eligible accepted testing. Because HIV testing in the intake area was new, we required strong administrative support to ensure cooperation from the medical and security staffs, whose primary goals were prompt triage and the maintenance of order. To our knowledge, there is no literature on rapid HIV testing in correctional facilities. A review of conventional test results collected in 1992–1998 at correctional facilities [4] reported that 3.4% of over 500 000 tests were positive, 56% in newly identified infections. A study among Texas correctional system's new inmates [5] showed a 2.5% HIV prevalence in female state jail detainees, a finding similar to our prevalence of 2.3% (0.9% rapid test positive and 1.4% self-reported HIV positive). Studies of rapid HIV tests have not systematically evaluated entry into care [1,6,7]. Most of our ED and STD clinic, but few jail participants, entered care. Although this may suggest that the jail testing venue was not productive, the reasons for this finding need further study. There are two important limitations to the generalizability of our results. First, we used dedicated, rather than indigenous staff to perform counseling, testing, and result reporting. By using existing providers, it may be possible to approach more individuals in large venues such as the ED. Second, until recently, the only US Food and Drug Administration-approved rapid HIV test was SUDS, which is categorized by Clinical Laboratory Improvement Amendments as moderately complex [8]. Three recently approved, new rapid HIV tests [8–11] are user friendly and one is Clinical Laboratory Improvement Amendments-waived; they afford point-of-care testing and should only improve the feasibility, turnaround time, and use of existing staff. In conclusion, we found that point-of-care rapid HIV testing was logistically feasible and acceptable to many participants and staff in three very different venues. All positive participants learned their results and most entered into care. The use of rapid HIV testing at similar sites may facilitate testing for many patients who do not perceive themselves at risk or who do not otherwise access medical care.