Coverage disparities in mobile health services for migrant workers in Korea: a spatial equity analysis.

Background: Migrant workers in the Republic of Korea face substantial barriers to healthcare due to linguistic, legal, and financial constraints, particularly among low-skilled labourers in high-risk occupations. Since 2008, the Korea Foundation for International Healthcare has operated a mobile clinic programme to deliver essential medical services to migrant workers. Despite its critical role, no systematic evaluation has been conducted to date. We examined the design and implementation of the 2024 programme, with a focus on regional disparities and health equity. Methods: We conducted a cross-sectional descriptive analysis of mobile clinic operations from May 2024 to March 2025 across 22 city- and district-level sites. We calculated coverage proportion as the number of clinic beneficiaries divided by the registered E-type visa holder population. We visualised spatial disparities using graduated symbol maps and analysed regional differences using the Kruskal-Wallis test, followed by Dunn's test with Bonferroni correction. Results: A total of 2336 migrant workers received services through 50 deployments, most of whom were male from Southeast and South Asia. Internal medicine (47.9%), general services (21.1%), and traditional Korean medicine (9.1%) were the most delivered services. Coverage ranged from 0.5% to 46.9% across regions. Higher coverage was observed in Seoul districts, while industrial hubs such as Hwaseong and Pyeongtaek showed lower outreach. There were no statistically significant differences in coverage proportions across the five regional clusters (H = 9.470; df = 4; P = 0.0503; 95% confidence interval = 4.37-17.51). However, post-hoc analysis identified a statistically significant difference between Seoul and Seoul Metropolitan Area excluding Seoul (z = 2.46; P = 0.0410; 95% confidence interval = 0.91-4.83). Civil society organisations played a central role in programme implementation. Conclusions: Mobile clinics provide a scalable, equity-oriented model to enhance the health access of migrant workers. However, addressing geographic disparities requires data-driven site selection and institutionalised collaboration with civil society. Locally adapted mobile clinic strategies are crucial for ensuring equitable access and the sustainable integration of migrant workers into healthcare systems. Registration: Open Science Framework (https://osf.io/wx7nz/).