Performance of a Validated Risk Score to Predict HIV-1 Acquisition Among African Women Participating in a Trial of the Dapivirine Vaginal Ring
Young women living in Eastern and Southern Africa continue to be at high risk of acquiring HIV-1, highlighting the urgent need for access to effective HIV-1 prevention interventions.1 Recent World Health Organization guidelines recommend that daily oral pre-exposure prophylaxis (PrEP) be offered as a priority prevention intervention for populations with an HIV-1 incidence of approximately 3% per year or higher.2 However, it is difficult to prospectively identify individuals who may be considered part of such populations, especially in generalized epidemics where risk may be heterogeneous, despite a high background HIV-1 prevalence. Empiric HIV risk assessment tools have been developed for several groups, including African heterosexual HIV-1 serodiscordant couples3 and men who have sex with men in the United States,4,5 in an attempt to discern those at the highest risk within these populations. These tools have been used in PrEP demonstration projects and as part of national guidelines to help guide PrEP implementation efforts.6 To attempt to identify women at higher risk of HIV-1 acquisition, we developed and validated a risk score using data from women who participated in several HIV-1 prevention trials.7 The score was derived from women who participated in MTN 003/VOICE, a phase IIB safety and effectiveness trial of oral and vaginal tenofovir-based PrEP.8 The VOICE risk score showed modest performance in identifying women at the highest risk of HIV-1 acquisition over the course of 1 year and having a risk score ≥3 correlated with an HIV-1 incidence of >3% per year. The VOICE risk score may represent a valuable tool to assist with targeted PrEP delivery in countries, such as South Africa and Kenya, that are in the process of scaling-up access to PrEP.9 However, further validation of the risk score is important for understanding the tool's performance when applied to different populations of women at risk of HIV-1 in these regions.
To further assess the VOICE risk score performance, we used data from women enrolled in MTN-020/ASPIRE, a randomized, double-blind, placebo-controlled, phase III trial of the safety and effectiveness of the dapivirine vaginal ring for HIV-1 prevention (Clinicaltrials.gov NCT01617096). Detailed methods and results for the trial have been published.10 Briefly, healthy, sexually active, HIV-1 uninfected women aged 18–45 years from Malawi, South Africa, Uganda, and Zimbabwe were enrolled and were tested monthly for HIV-1 using rapid antibody tests for a minimum of 1 year. Participants provided written informed consent, and applicable local and national ethical and regulatory authorities approved the study protocol.
The risk score was applied to data collected from ASPIRE participants at enrollment. The VOICE risk score is calculated based on taking the sum of the point values that correspond to the following factors assessed at enrollment: age <25 years = 2 points; unmarried or not living with partner = 2 points; partner does not provide financial or material support = 1 point; primary partner has other partners (yes or do not know) = 2 points; alcohol use in the past 3 months = 1 point; having a curable sexually transmitted infection (STI) at baseline = 1 point; herpes simplex virus type 2 status = 2 points. In ASPIRE, data were not collected on living with primary partner, partner provides financial support, or herpes simplex virus type 2 status; therefore, we were unable to allocate points for those factors. Participants were included in the analysis if they had complete data for all the other baseline factors assessed in the risk score.