Objective: Evaluate a computerized intervention supporting anti-retroviral therapy (ART) adherence and HIV transmission prevention. Design: Longitudinal randomized controlled trial. Settings: An academic HIV clinic and a community-based organization in Seattle. Subjects: In a total of 240 HIV-positive adults on ART, 209 completed 9-month follow-up (87% retention). Intervention: Randomization to computerized counseling or assessment only, 4 sessions over 9 months. Main Outcome Measures: HIV-1 viral suppression, and selfreported ART adherence and transmission risks, compared using generalized estimating equations. Results: Overall, intervention participants had reduced viral load: mean 0.17 log(10) decline, versus 0.13 increase in controls, P = 0.053, and significant difference in ART adherence baseline to 9 months (P = 0.046). Their sexual transmission risk behaviors decreased (odds ratio = 0.55, P = 0.020), a reduction not seen among controls (odds ratio = 1.1, P = 0.664), and a significant difference in change (P = 0.040). Intervention effect was driven by those most in need; among those with detectable virus at baseline (>30 copies/mL, n = 89), intervention effect was mean 0.60 log10 viral load decline versus 0.15 increase in controls, P = 0.034. ART adherence at the final follow-up was 13 points higher among intervention participants versus controls, P = 0.038. Conclusions: Computerized counseling is promising for integrated ART adherence and safer sex, especially for individuals with problems in these areas. This is the first intervention to report improved ART adherence, viral suppression, and reduced secondary sexual transmission risk behavior
