{
  "abstract": "Background Prevention efforts targeting adolescents are crucial for increasing awareness about HIV in the general population. Since 2015 we have implemented a community-led programme for comprehensive sexuality education in secondary schools in the metropolitan area of Milan.Methods Before and after educational sessions, students are invited to complete an anonymous online survey assessing knowledge of HIV and STIs using standardized pre- and post-intervention questionnaires (10 questions; score range 0–1). We conducted a pre–post observational study based on completed questionnaires.Improvement analyses included only students completing both questionnaires and not achieving maximum baseline score. Knowledge gain was calculated as the difference between post- and pre-intervention scores. Multivariable linear regression identified determinants of knowledge improvement, while multivariable logistic regression assessed factors associated with questionnaire completion.Independent variables included age, gender, school year, type of school, perceived interest and importance of the intervention, prior exposure to similar interventions, and sources of sexual health information.Results We delivered 25 educational sessions and reached nearly 600 students across 3 schools between Dec. ‘25 and Mar. ‘26. A total of 548 students completed at least the pre-intervention questionnaire and 391 completed both. Mean knowledge score increased from 0.60 (95% CI: 0.58–0.62) at baseline to 0.69 (95% CI: 0.67–0.71) post-intervention, corresponding to an absolute mean difference of 0.093 (95% CI: 0.074–0.111;p<0.001).The multivariable linear regression model showed limited explanatory power (n=391; R 2 = 0.136;global p=0.058). A neutral perception of the intervention’s importance was significantly associated with lower knowledge gains (β=−0.117;p<0.001), as also prior participation in similar educational interventions (β=−0.116;p=0.018). Demographic variables (age, gender, school year) were not significantly associated with knowledge gains. In logistic regression,school type emerged as the main determinant of questionnaire completion (n=548; pseudo R2 ≈ 0.19; p<0.001). Students attending high schools (OR 4.93; 95% CI: 2.47–9.86;p<0.001) and technical institutes (OR 2.44; 95% CI: 1.35–4.39;p=0.003) were significantly more likely to complete both questionnaires than students attending vocational/professional schools. No significant associations were observed for age or gender.Conclusions Knowledge improvement following school-based HIV/STI education was modest but significant and only partially explained by socio-demographic factors, while it was more strongly associated with students’ perceived relevance of the intervention. Questionnaire completion was primarily associated with school type. These findings highlight the importance of motivational engagement strategies and school-level factors to maximize the effectiveness of HIV/STI educational programmes for adolescents.",
  "authors": [
    {
      "affiliations": [
        "ASA Associazione Solidarietà AIDS ODV, Milano, Italy"
      ],
      "name": "P Testoni"
    },
    {
      "affiliations": [
        "ASA Associazione Solidarietà AIDS ODV, Milano, Italy"
      ],
      "name": "C Soligo"
    },
    {
      "affiliations": [
        "ASA Associazione Solidarietà AIDS ODV, Milano, Italy"
      ],
      "name": "P Vinti"
    },
    {
      "affiliations": [
        "ASA Associazione Solidarietà AIDS ODV, Milano, Italy"
      ],
      "name": "F Rossi"
    },
    {
      "affiliations": [
        "ASA Associazione Solidarietà AIDS ODV, Milano, Italy"
      ],
      "name": "A Bianchi"
    },
    {
      "affiliations": [
        "ASA Associazione Solidarietà AIDS ODV, Milano, Italy"
      ],
      "name": "D Zagato"
    },
    {
      "affiliations": [
        "San Raffaele Hospital, Milano, Italy"
      ],
      "name": "M Cernuschi"
    }
  ],
  "title": "OC57 Comprehensive sexuality education in secondary schools 2025-2026",
  "uid": "2de992d2-c449-54cb-967d-6cc0c80bd0d8"
}