The Assessment of Structural Validity and Internal Consistency of the Polish Health Literacy Questionnaire (HLQ) in Primary Care Settings

Background/Objectives: Health literacy extends beyond individual competencies and encompasses how people engage with health systems. The Health Literacy Questionnaire (HLQ) is a widely used multidimensional instrument designed to assess different health literacy aspects across nine distinct domains. This study aimed to examine structural validity and internal consistency of the Polish version of the HLQ among primary care service users. Methods: The HLQ was used in a cross-sectional survey among 360 adults (mean age 51.76 years, SD 17.48) attending four primary care clinics in Poland. The assessment included confirmatory factor analysis (CFA) and internal consistency tests. Results: A nine-factor CFA model was applied to the HLQ items, without allowing cross-loadings or correlated residuals. The fit indices confirmed good model fit: χ2WLSMV (df = 866) = 1175.63, p < 0.001; CFI = 0.98; TLI = 0.98; RMSEA = 0.038; and SRMR = 0.056. The factor loadings ranged from 0.55 to 0.94, indicating acceptable item–factor relationships across all domains. Internal consistency was satisfactory across all nine domains, with composite reliability ranging from 0.76 to 0.87 and Cronbach’s alpha from 0.78 to 0.88. Conclusions: The findings provide preliminary evidence supporting structural validity and internal consistency of the Polish HLQ in this sample of primary care service users and suggest the potential value of the instrument for multi-dimensional assessment of health literacy in similar Polish primary care populations. Future studies should evaluate additional measurement properties of the tool, as well as the performance of the instrument in nationally representative samples and across diverse clinical settings.