An Empiric HIV Risk Scoring Tool to Predict HIV-1 Acquisition in African Women

OBJECTIVE:To develop and validate an HIV risk assessment tool to predict HIV acquisition among African women. DESIGN:Data were analyzed from three randomized trials of biomedical HIV prevention interventions among African women (VOICE, HPTN 035 and FEM-PrEP). METHODS:We implemented standard methods for the development of clinical prediction rules to generate a risk-scoring tool to predict HIV acquisition over the course of one year. Performance of the score was assessed through internal and external validation. RESULTS:The final risk score resulting from multivariable modeling included age, married/living with a partner, partner provides financial or material support, partner has other partners, alcohol use, detection of a curable sexually transmitted infection, and herpes simplex virus-2 serostatus. Point values for each factor ranged from 0 to 2, with a maximum possible total score of 11. Scores ≥5 were associated with HIV incidence >5 per 100 person-years and identified 91% of incident HIV infections from among only 64% of women. The area under the curve (AUC) for predictive ability of the score was 0.71 (95% confidence interval [CI] 0.68, 0.74), indicating good predictive ability. Risk score performance was generally similar with internal cross-validation (AUC=0.69; 95% CI 0.66, 0.73), and external validation in HPTN 035 (AUC=0.70; 95% CI 0.65, 0.75) and FEM-PrEP (AUC=0.58; 95% CI 0.51, 0.65). CONCLUSIONS:A discrete set of characteristics that can be easily assessed in clinical and research settings were predictive of HIV acquisition over one year. Use of a validated risk score could improve efficiency of recruitment into HIV prevention research and inform scale-up of HIV prevention strategies in women at highest risk.