Introduction Interactive computer-based interventions (ICBI) are potentially scalable tools for use in real-world settings to promote sexual health and prevent sexually transmitted infections (STIs) and unintended pregnancies. We assessed the feasibility and acceptability of an ICBI for sexual health and the effectiveness of the intervention in reducing unprotected sex and biomarker outcomes of STIs and unintended pregnancy.

Methods This pilot randomised controlled trial enrolled STD Clinic patients, 14–24 years old, reporting unprotected vaginal sex during the last 2 months. The ICBI included personalised sexual health feedback from a physician avatar; instructive video modules advocating sexual health; and identification of one behaviour to change. At 3-month follow-up participants reported on interim sexual and pregnancy histories and underwent repeat urine testing. Intervention impact on unprotected vaginal sex, number of sexual partners, incident STIs and unintended pregnancy was assessed.

Results Of 272 participants, 242 (89%) completed the study, of which 65% were female. At 3-month follow-up, when compared to controls, the intervention group reported a 33% lower rate of vaginal sex without condoms [IRR = 0.67, 95% CI: 0.44–1.01]; 20% fewer partners [IRR = 0.80, 95% CI: 0.61–1.05]; 48% fewer STIs [IRR = 0.52, 95% CI: 0.24–1.13]. Intervention females reported less frequent vaginal sex without birth control [IRR = 0.78, 95% CI: 0.46–1.32]; half as many unintended pregnancies [IRR = 0.51, 95% CI: 0.16–1.6]. In exploratory analyses, intervention females reported fewer partners [IRR = 0.71, 95% CI: 0.50–1.00] and a significantly lower rate of vaginal sex without condoms [IRR = 0.50, 95% CI: 0.30–0.85].

Conclusion The intervention was acceptable to both males and females, and at 3-month follow-up, there was a non-significant but substantial trend towards effectiveness for all outcomes. Among females, in exploratory analysis, the reduction in vaginal sex without condoms was statistically significant.

Disclosure of interest statement Test kits for STI testing were provided by GenProbe.