Evaluating Pay-It-Forward Strategy to Promote Hepatitis B Virus and Hepatitis C Virus Testing Among International Migrants From Low- and Middle-Income Countries in China: Protocol for a Cluster Randomized Controlled Trial.

Background: Hepatitis B virus (HBV) and hepatitis C virus (HCV) are significant global health concerns, particularly prevalent in low- and middle-income countries (LMICs). In China, a significant number of international migrants from LMICs reside, many of whom are at high risk of HBV and HCV infection, while this group tends to engage in low HBV and HCV test use due to some adverse factors. Pay-it-forward (PIF) is a social innovation strategy that is based on the theories of upstream reciprocity and mutual aid. Previous studies have shown that the PIF strategy has proven effective in promoting sexually transmitted infections (STIs) testing in various populations. Objective: This study aims to evaluate the effectiveness of a PIF intervention in promoting HBV and HCV testing among international migrants from LMICs in China. Methods: A 2-arm cluster randomized controlled trial (RCT) will be conducted in Guangzhou, China. Participants will be recruited from a public hospital serving a large migrant community. A total of 100 eligible participants will be enrolled in blocks of 5 using a cluster randomization plan and randomly assigned to either the PIF intervention arm or the control arm in a 1:1 ratio. Participants in the intervention arm will watch a 2-minute video introducing the PIF concept and receive printed educational materials on HBV and HCV. Participants will then be offered free testing donated by previous participants, which they can accept or decline, and an opportunity to make a monetary donation to cover testing for a future participant. Control arm participants will receive standard medical services, with self-paid testing. The primary outcome is the proportion of participants tested for both HBV and HCV. Data will be collected through a self-administered questionnaire, and test information will be obtained from the hospital's medical records without personally identifiable information. The survey data will be analyzed using generalized estimating equations to account for clustering effects. Results: This protocol was completed in August 2024, and implementation was conducted from September 2024 to February 2025. According to the baseline survey findings, 73.0% (73/100) of the 100 eligible participants recruited were male, 87.0% (87/100) were from African countries, and 85.0% (85/100) came to China for business purposes. About 40.0% (40/100) earned more than US $1100 per month, 62.0% (62/100) were married, and 6% (6/100) had both stable and casual sexual partners. Conclusions: This study is innovative in targeting international migrants from LMICs in China and using the PIF strategy to promote HBV and HCV testing. The PIF intervention is expected to increase testing rates by addressing financial barriers and fostering community support. The findings will contribute to the understanding of HBV and HCV testing promotion among this understudied population, with potential implications for public health policy and practice.