The goal of this study is to learn whether a digital tool can help improve HIV knowledge, self-awareness, and testing among adolescents in Yogyakarta, Indonesia. The tool includes online HIV education, a self-assessment for HIV risk, and access to trained peer educators for support. The study will also explore how comfortable and willing adolescents are to use this kind of digital health service.

The main questions the study aims to answer are:

• Can this digital tool help adolescents better understand HIV and their personal risk?
• Will more adolescents be willing to get tested for HIV after using the tool?
• What factors affect whether adolescents accept and use digital HIV services?

Researchers will compare two groups of high school students:

• One group will use the digital tool for 6 weeks
• The other group will receive standard HIV education (not through the tool)

Participants will:

• Answer surveys before and after the 6-week period
• Learn about HIV through videos and interactive content
• Use the tool to assess their personal HIV risk
• Receive support from trained peer educators (online)

The researchers hope this study will lead to new ways of using technology to improve HIV prevention and testing for young people.

This study is designed to develop and evaluate a digital-based model for HIV education and self-screening aimed at increasing HIV-related knowledge, self-awareness of risk, and testing uptake among adolescents in Yogyakarta, Indonesia. Despite widespread access to digital technology, adolescent HIV testing coverage remains low due to stigma, limited knowledge, privacy concerns, and lack of youth-friendly services. The intervention model, named EKSTRIM (Edukasi dan Skrining HIV Mandiri), will be developed using a research and development framework based on the ADDIE model, which includes the stages of Analysis, Design, Development, Implementation, and Evaluation.

The study will proceed in three phases. In Phase I, an explanatory sequential mixed-methods design will be employed to assess the readiness, needs, and perceptions of adolescents and HIV program implementers regarding the use of digital platforms for HIV education and self-screening. Quantitative data will be collected through structured questionnaires, followed by qualitative data from focus group discussions and in-depth interviews. This phase will inform the technical and content requirements for the intervention.

Phase II will involve the design and development of the digital intervention model. The EKSTRIM platform will include interactive web-based modules on HIV prevention, a self-risk screening tool, peer educator support features, and links to adolescent-friendly HIV services. The platform will be evaluated using McCall's Quality Model to ensure functionality, reliability, and user-friendliness.

Phase III will test the effectiveness of the model using a double-blind, parallel-group randomized controlled trial with a pretest-posttest design. A total of 400 adolescents will be recruited using cluster random sampling from high schools in Yogyakarta. Participants will be randomly allocated to either the intervention group, which will access the EKSTRIM platform, or the control group, which will receive standard HIV educational materials. The intervention period will last six weeks.

Primary outcomes will include changes in HIV-related knowledge, self-awareness of HIV risk, and HIV testing uptake. Data analysis will involve general linear models, non-parametric tests (Wilcoxon and Mann-Whitney), difference-in-difference analysis, and multilevel linear modeling to assess the intervention's impact and identify contributing factors. It is anticipated that the digital intervention will lead to significant improvements in the targeted outcomes and that factors such as stigma, digital acceptance, and initial understanding of HIV will influence results.

This study aims to provide scientific evidence on the effectiveness of a digital, adolescent-centered HIV intervention that emphasizes privacy, peer support, and accessibility. The model is expected to be a scalable and sustainable solution for HIV prevention among youth and may inform broader policy and programmatic strategies at the local and national levels. Ethical approval will be obtained prior to study initiation, and all participants will provide informed consent or assent, with parental or guardian consent obtained as required under national regulations.

Inclusion Criteria:

• Adolescents aged 15-17 years
• Reside or attend school in the Yogyakarta area
• Currently enrolled in one of the participating high schools
• Able to read and understand Bahasa Indonesia
• Own or have regular access to a smartphone or digital device with internet connectivity
• Provide informed assent to participate in the study
• Have obtained written parental or guardian consent

Exclusion Criteria:

• Adolescents outside the 15-17 age range
• Unable to access digital devices or internet independently
• Previously diagnosed with HIV (as this study targets prevention and self-screening among untested adolescents)
• Unwilling or unable to provide informed assent or whose parents/guardians do not provide consent
• Currently participating in another HIV-related intervention study

Individual participant data (IPD) will not be shared due to ethical and legal considerations related to adolescent privacy and consent. The study involves minors, and sharing of their sensitive health-related data, even in de-identified form, poses potential confidentiality risks. Data use is restricted by local institutional review board (IRB) protocols and national data protection regulations in Indonesia.

This study uses a double-blind design in which both participants and investigators are unaware of group allocation (intervention or control). The outcomes assessor is also blinded to minimize assessment bias. Only the data analyst, independent from the implementation team, will have access to the allocation code after data collection is complete.