Adaptive engagement within a prospective registry: tracking health, occupation, and social dynamics among female sex workers in Southern Sichuan.

backgroundFemale sex workers (FSWs) face elevated health risks, including sexually transmitted infections (STIs), mental health challenges, and violence-often exacerbated by stigma and legal constraints in China. Longitudinal research integrating health trajectories, occupational shifts, and social support remains limited but is essential for public health response. This protocol outlines a prospective registry study of FSWs in southern Sichuan, aiming to both monitor longitudinal dynamics and evaluate an adaptive engagement strategy within the registry system.

methodsThis multi-center, prospective registry will be established in Luzhou, Yibin, Neijiang, and Zigong. FSWs aged 18 and older will be recruited via initial referrals from health institutions/NGOs and subsequent snowball sampling. Upon enrollment and baseline data collection, participants will be randomized (1:1) into one of two groups: (1) Standard Registry Follow-up, involving scheduled contacts (e.g., quarterly brief check-ins, annual comprehensive interviews) focused primarily on data collection; or (2) Adaptive Registry Engagement, incorporating the standard schedule plus proactive, tailored support and contact adjustments based on participant-reported needs or risk indicators identified through registry data (e.g., intensified contact following reported violence, tailored health information messages, facilitated service referrals). Data collection will encompass field epidemiological surveys (demographics, comprehensive health status including psychological scales, social support, occupational experiences, employment, sexual behavior, narrative accounts) and integration of data from existing health systems where feasible. A modular database (Basic Information, Health Records, Narrative Data, Social Networks, Occupational Dynamics) will ensure secure and organized data management with rigorous quality control. Statistical analyses will include descriptive summaries, correlation analyses, time-series modeling, qualitative thematic analysis, mixed-methods integration, path analysis, and comparative analyses between the two engagement groups on outcomes like retention, data completeness, service utilization, and potentially key health indicators. DISCUSSION: This study is the first to implement a prospective registry for FSWs in Southwest China and uniquely embeds an evaluation of engagement models. By comparing standard and adaptive follow-up approaches, the study examines whether personalized contact improves registry performance and participant support. Findings will generate critical longitudinal insights and guide future research, interventions, and policies tailored to vulnerable populations, while addressing the contextual challenges of implementation in China.