Participation in this study will be entirely voluntary, and comprehensive measures will be implemented to ensure participant anonymity and data confidentiality. The study protocol has been reviewed and approved by the Ethics Committee of the Chengdu CDC (Approval No. 2024021).

All participants were required to carefully read the electronic informed consent form prior to enrollment, which will provide detailed information about the study purpose, procedures, potential risks, and benefits. Only those who voluntarily select the “Agree” option will be permitted to proceed with the questionnaire, thereby documenting their informed consent. Participants will have the right to withdraw from the study at any time without any negative consequences.

To prevent coercion or power imbalance between peers, volunteers, and participants were matched across different universities; all volunteers must sign a confidentiality agreement; all participation is anonymous and voluntary. We also conducted dedicated confidentiality training during the pre-project orientation.

To support HIV prevention efforts, the study will provide access to evidence-based online health education, individualized counseling services, and free prevention supplies, including condoms, lubricants, and HIV/STI self-testing kits. Additionally, participants will receive modest financial compensation for completing each survey, in recognition of their time and contribution. Participants received RMB 20 (US $2.83) at baseline, RMB 20 (US $2.83) at the 6-month follow-up, and RMB 20 (US $2.83) at the final 12-month follow-up.

Potential risks primarily will involve the possible inadvertent disclosure of sensitive information related to sexual behavior. However, robust data security and privacy protection protocols will be established, including data encryption, pseudonymization of identifiers, and restricted access to sensitive information, to minimize this risk.

The anticipated benefits of participation—including increased HIV-related knowledge, improved access to prevention services, and facilitation of early detection and timely linkage to care—are expected to outweigh the minimal risks involved.

Findings from this study will be disseminated to local and national public health authorities to inform HIV prevention strategies targeting students belonging to the student MSM population. In addition, study results will be shared with the broader scientific community through peer-reviewed publications and academic conference presentations.

This prospective cohort study aims to evaluate the effectiveness of a comprehensive Internet-based intervention targeting student MSM attending university. Specifically, it seeks to assess the intervention’s impact on reducing HIV-related high-risk behaviors and lowering the prevalence of HIV and other STIs within this population, using a before-and-after controlled trial design.

The study evolved from a 2024 local public health intervention pilot. During the ethical review in June 2024, the local ethics committee recommended that, given the sensitivity and vulnerability of university student participants, all eligible students should receive access to the intervention resources and that establishing a nonintervention control group would be ethically inappropriate. Considering this recommendation and the small, hard-to-reach population size, a randomized controlled trial was deemed infeasible. Therefore, a before-after self-controlled cohort design was adopted, allowing participants to serve as their own controls to assess within-person changes.

Guided by findings from systematic reviews indicating that a 12-month intervention period is optimal for achieving behavioral changes [14], this study will set a 12-month intervention duration, with an interim follow-up assessment at 6 months.

This study is scheduled to commence in June 2025 and conclude in June 2026. The research process will consist of the following sequential phases: participant recruitment, HIV/hepatitis C virus (HCV)/hepatitis B surface antigen (HBsAg)/syphilis testing, baseline survey, intervention implementation, midterm survey, and final follow-up survey.

Participant recruitment will be conducted exclusively through two internet-based channels to maximize efficiency and ensure privacy. The recruitment period is expected to last for 1 month. To ensure balanced workload distribution, each volunteer will have a preassigned recruitment quota. Once a volunteer has reached their quota, subsequent applicants will be redirected to other available volunteers. Given the estimated total sample size and the involvement of 10 student volunteers, it is calculated that each volunteer will be responsible for recruiting approximately 50 eligible student MSM participants.

Participants who complete the baseline and follow-up survey will receive a modest monetary incentive. This compensation strategy serves two primary purposes: (1) to acknowledge participants’ time and effort and (2) to foster participant retention by establishing a sense of commitment and accountability within the study.

Specifically, participants received RMB 20 (US $2.83) at baseline, RMB 20 (US $2.83) at the 6-month follow-up, and RMB 20 (US $2.83) at the final 12-month follow-up. The incentive amounts were reviewed and approved by the Ethics Committee of the Chengdu CDC (Approval No. 2024021). The total compensation has been carefully calibrated to ensure it remains modest and noncoercive while promoting continued engagement.

This incentive structure also incorporates behavioral-economics principles such as loss aversion, in which participants risk forfeiting future incentives if they withdraw prematurely. This approach encourages consistent participation without exerting undue influence.

The study will utilize the quadruple rapid diagnostic test kit developed by Guangzhou Wondfo Biotech Co., Ltd. This assay enables the simultaneous qualitative detection of HIV-1/2 antibodies, HCV antibody, HBsAg, and Treponema pallidum antibody from whole blood, serum, or plasma samples. The test employs a lateral flow immunochromatographic assay and provides results within 15 minutes.

Each test kit includes a test cassette, desiccant pouch, dropper, and buffer vial. The HIV-HCV-HBsAg-Syphilis Combo Test is approved by the China National Medical Products Administration, ensuring its safety and efficacy for clinical application.

Independent evaluations have reported excellent diagnostic performance, with sensitivities of 99.70% for HIV, 98.71% for HCV, 98.97% for HBsAg, and 98.47% for syphilis, along with corresponding specificities of 100%, 99.33%, 99.78%, and 99.68%, respectively. This highly reliable and user-friendly assay is particularly well-suited for point-of-care testing and large-scale screening initiatives, enabling timely diagnosis and facilitating rapid linkage to appropriate health care services [22].

Baseline data collection will be conducted via an online self-administered questionnaire. Assigned project volunteers will securely deliver the survey link to participants through encrypted messaging channels.

An electronic informed consent process will be embedded at the beginning of the baseline questionnaire. Participants will be required to carefully read the informed consent form, which details the purpose of the study, potential risks and benefits, data confidentiality measures, and their rights as participants. Only after acknowledging their understanding and agreement will participants be permitted to proceed with completing the survey.

To ensure participant anonymity while allowing for longitudinal data linkage, a de-identified participant code will be generated for each individual at enrollment. The participant ID consists of a randomly generated alphanumeric string created through an independent encryption algorithm, ensuring that no elements of phone numbers, timestamps, or other personally identifiable information (PII) are embedded in the code. The mapping file linking IDs with PII will be stored separately in an encrypted database accessible only to authorized Chengdu CDC data managers.

All study data are managed within a comprehensive data protection and security framework, consistent with national and international privacy standards. PII (such as phone numbers, WeChat IDs, and mailing addresses) is collected solely for operational purposes and stored separately from deidentified research data. Both databases are encrypted at rest and during transmission using the Advanced Encryption Standard (AES-256) encryption protocol implemented within the Chengdu CDC secure data environment.

A Data Protection Impact Assessment was performed to identify potential privacy risks and define mitigation strategies, including data-flow mapping, encryption and storage measures, access-control policies, retention and deletion schedules, and oversight procedures.

Access to data is governed by role-based access control, ensuring that each staff member only accesses the data required for their function. Multifactor authentication (eg, password+phone verification) is required for system login. All access and data modification activities are recorded through automated audit logs, which are periodically reviewed by the Chengdu CDC data security officer.

In accordance with the approved data retention and deletion schedule, PII will be retained for up to 6 months after study completion and then permanently deleted from all servers. Deidentified research data will be securely stored for 5 years for potential secondary analysis and subsequently removed after encrypted archiving.

These combined administrative, technical, and procedural safeguards ensure participant anonymity and protect the confidentiality, integrity, and traceability of all data throughout the study lifecycle.

Participants will complete a baseline questionnaire upon enrollment, which collects detailed information on sociodemographic characteristics, sexual behaviors, HIV-related knowledge, attitudes, practices, and other relevant behavioral factors (see Multimedia Appendix 3 for details).

Follow-up surveys will be administered at two time points post-intervention: 6 months and 12 months. The content of the follow-up questionnaires will be identical to that of the baseline survey to enable assessment of changes over time (see Multimedia Appendix 4 for follow-up questionnaire content). Data collection instruments and operational manuals have been standardized to ensure consistency in measurement and facilitate reproducibility across different investigators.

To enhance the understanding of the student MSM volunteers on the project rationale and improve their capacity to implement interventions, a structured training program will be provided prior to project initiation. This training will include both theoretical and practical components, such as (1) lectures to be delivered by experts and CBO trainers on HIV prevention strategies (eg, PrEP and PEP), online counseling skills, and psychological communication techniques; (2) practical simulation exercises focusing on real-world scenarios and case discussions; (3) orientation sessions explaining project-specific tasks, performance assessment indicators, and operational guidelines.

The study has three predefined endpoints:

Time schedule of enrollment, interventions, assessments, and visits for participants are presented in Table 2.

Survey data will be collected through Wenjuanxing, an online survey platform developed and operated by Ranxing Information Technology Co., Ltd., based in Changsha, China [26]. Wenjuanxing provides an automated data archiving system designed to ensure the integrity, security, and consistency of submitted responses.

All survey data will be stored on secure servers hosted by Alibaba Cloud in Hangzhou, China. The server infrastructure is protected by enterprise-level firewall systems, with daily automated data backups to prevent potential data loss and ensure disaster recovery capabilities.

Access to the database is strictly controlled through a role-based access control system. Only authorized research personnel, who have signed confidentiality agreements, will be granted access to view or manage the data. User authentication protocols, including secure passwords and encrypted data transmission, are implemented to further enhance data security and prevent unauthorized access.

Upon completion of data collection, all survey data will be exported from the Wenjuanxing platform for data cleaning and preprocessing to ensure accuracy, completeness, and consistency. Data management and analysis will be conducted using established statistical software packages, including SPSS, Stata, or R.

Descriptive statistics will be used to summarize participant characteristics and key study variables. Categorical variables will be presented as frequencies and percentages, while continuous variables will be reported as means with SD or medians with IQR, depending on data distribution. The normality of continuous variables will be assessed using Shapiro-Wilk tests and visual inspection of histograms/Q–Q plots. Univariate analyses, such as chi-square tests for categorical variables and t tests or nonparametric tests for continuous variables, will be used to assess preliminary associations between independent variables and outcome measures. Multivariate analysis will be performed using logistic regression models (for binary outcomes) to identify factors independently associated with key study end points, adjusting for potential confounders. If advanced statistical modeling (eg, Cox proportional hazards models, generalized estimating equations) is deemed necessary to address specific research questions or to handle longitudinal data, additional statistical expertise will be sought to ensure appropriate application and interpretation of these methods. A 2-sided P value <.05 will be considered statistically significant.

Feasibility will be assessed by examining recruitment and retention rates, completeness of follow-up surveys, and timeliness of testing. Acceptability will be evaluated through participant satisfaction surveys and qualitative feedback collected from peer volunteers regarding the practicality and perceived usefulness of the intervention materials. Descriptive statistics will be used to summarize feasibility and acceptability outcomes, and qualitative comments will be thematically analyzed.

This prospective cohort study will be uniquely designed to evaluate the effectiveness of an internet-based intervention in reducing HIV-related high-risk behaviors and the prevalence of HIV and other STIs among university student MSM. Beyond addressing the primary study objectives, the research will innovatively integrate digital engagement strategies with peer-led support, representing a pioneering approach within this population.

Specifically, the study will establish a dedicated intervention cohort that will utilize social networking platforms to deliver continuous behavioral interventions, promote HIV/STI testing, facilitate service referrals, and provide financial subsidies to support access to PEP.

A key innovation of this study will be the application of the Network Intervention Cohort Peer Model, which will involve recruiting experienced staff from MSM CBOs as trainers and engaging university student MSM volunteers as frontline interventionists. This model is expected to enhance the cultural relevance and acceptability of the intervention while addressing critical limitations of conventional peer education programs.

Furthermore, all interventions will be delivered entirely online, aligning with current trends in MSM-focused health promotion. The intervention package will integrate both behavioral and biomedical components—including the discreet distribution of condoms and lubricants by mail, as well as financial subsidies to support timely initiation of PEP when indicated. Prior research has demonstrated that eliminating financial barriers is a key strategy for empowering MSM to access and sustain engagement with essential HIV prevention services [28].

Recent regulatory tightening surrounding CBO activities—particularly in relation to direct engagement with university students—has significantly constrained the scope of traditional peer education efforts. While Chengdu has previously mobilized college student volunteers through partnerships with local CDCs and AIDS Prevention Associations, such initiatives have generally been broad-based and not specifically tailored to the distinct needs of university student MSM.

Against this backdrop, our project will represent the first known effort in China to design and implement a comprehensive, peer-led network intervention model specifically targeting this demographic.

Despite the study’s innovative strengths, several anticipated operational challenges merit careful consideration.

The project relies on CBO staff serving as trainers and student MSM volunteers acting as interventionists. Ensuring consistency and quality in training and mentoring is critical to maintaining intervention fidelity. Variability in training delivery or gaps in knowledge may lead to inconsistent intervention outcomes.

To address this, trainers will be selected from experienced CBO staff across Chengdu with a demonstrated track record in intervention delivery and volunteer mentoring. All volunteers are required to complete the entire capacity-building training and pass a posttraining assessment before participating in interventions. During the intervention process, volunteers can consult their trainers at any time regarding operational issues, such as making referrals or responding to participant inquiries, and can also seek support through the project’s online group chat.

Maintaining participant retention throughout the 12-month follow-up period is crucial to ensuring sufficient statistical power and minimizing attrition bias. While multiple recruitment strategies and financial incentives have been planned, challenges in achieving the targeted sample size may still arise.

To mitigate this risk, contingency plans include expanding recruitment channels, such as peer referrals and targeted social media advertisements, if enrollment falls short. Additionally, each participant will be required to provide both their WeChat contact and mobile phone number upon enrollment. Participants will also be informed that this information, along with their mailing address, will be used solely for study-related purposes, such as the confidential delivery of condoms, lubricants, and other prevention materials, which may help improve retention and engagement.

The baseline survey collects sensitive data, including sexual behaviors, substance use, and HIV-related risk factors. Due to social desirability bias or privacy concerns, participants may underreport or misreport behaviors, potentially affecting data accuracy.

To address this, volunteers will emphasize the project’s strict confidentiality protocols when inviting participants to complete the questionnaire. Participants will be clearly informed that no PII is collected in the survey, all data are securely stored in the back-end system, and only the project manager has access to detailed records.

This study has limitations. The before-after self-controlled cohort design does not include a concurrent control group, which limits the ability to make causal inferences. However, a randomized controlled trial was not feasible due to ethical and operational considerations—specifically, the local ethics committee’s recommendation that all eligible university students should have access to the intervention resources. To mitigate this limitation, we will compare changes observed in this study with contemporaneous surveillance data from the Chengdu student MSM population, conduct sensitivity analyses to assess secular trends, and interpret outcomes cautiously in light of these contextual factors. Despite these constraints, the design remains appropriate for evaluating real-world implementation and effectiveness under routine public health conditions. While the assumed reduction in incidence may be optimistic, behavioral indicators such as HIV testing and PEP/PrEP uptake serve as sensitive early markers of intervention impact in this short-term cohort. Given the expected rarity of incident infections over 12 months in student MSM cohorts, we interpret incidence changes cautiously while relying on proximal behavioral outcomes with higher short-term sensitivity.

By proactively addressing these anticipated challenges through standardized training, robust recruitment and retention strategies, and comprehensive privacy protections, this study aims to ensure rigorous implementation while generating valuable insights into the feasibility and effectiveness of internet-based, peer-led HIV prevention interventions among university student MSM.