Applying theory to develop and validate the Universal Health Coverage Literacy Scale: a new measurement for the Thai context

Background: Universal health coverage (UHC) literacy is vital for promoting equitable access to healthcare. However, Thailand lacks a validated tool specifically designed to measure UHC literacy within its cultural context. This study aimed to develop and validate such a tool, named the Universal Health Coverage Literacy Scale for the Thai Context (UHCL:TH). Methods: A two-phase cross-sectional study design was employed. Phase 1 involved a literature review and identification of the tool’s key components through a two-round Modified Delphi Method process conducted with 19 multidisciplinary experts. Phase 2 focused on tool development and validation. Reliability was tested with 60 participants. Exploratory factor analysis (EFA) was performed on data from 500 Thai adults selected via multistage sampling. Factors were extracted using maximum likelihood with varimax rotation. Results: The final scale comprised 20 items across three components: Access, Understanding, and combined Appraisal–Application. EFA explored the factor structure, accounting for 75.11% of the total variance. The internal consistency was acceptable (Cronbach’s alpha = 0.938). Conclusions: These results indicate that UHCL:TH is a valid, reliable, and culturally relevant instrument for assessing UHC literacy. The three-component structure enables targeted interventions, aids national monitoring of equitable reach, and informs policy strategies to reduce health disparities. Keywords: Universal Health Coverage, UHC literacy, Scale development, Construct validity, Reliability, Exploratory factor analysis