Psychometric properties of the vaccination fear scale (VFS-6) in Polish and their relationship with psychological distress

Introduction: Preventing vaccine hesitancy is an important effort by the clinician. The present study aimed to evaluate the factorial structure and psychometric properties of the Vaccination Fear Scale (VFS) in a Polish sample, as well as to examine its measurement invariance across sex and its associations with psychological distress. Methods: A sample of 455 adults from the general population, broadly representative of the general Polish adult population, (Mean age = 37.05, SD = 13.14; 72.3% female) was recruited. Participants completed the seven-item version of the VFS. A subsample of 153 individuals also completed the 21-items Depression, Anxiety, and Stress Scale (DASS-21). Confirmatory factor analyses (CFA) were conducted to compare unidimensional, two correlated factors, and second-order two-factor models for 7-items and 6-items versions. Results: Results indicated that the 6-item version of the VFS (VFS-6), excluding item 5, provided superior fit compared to the 7-item version. The best-fitting model was a two-factor correlated structure (Cognitive factor: items 1, 2, and 4; Somatic factor: items 3, 6, and 7), confirming a clear cognitive-somatic structure. Measurement invariance analyses supported strict invariance between sexes. Internal consistency was high for both the total scale and its subfactors, and convergent and discriminant validity were satisfactory. Conclusion: Correlations with DASS-21 scores were low and non-significant, suggesting that vaccination fear is largely independent of general psychological distress measured as depression, anxiety and stress. These findings demonstrate that the VFS-6 is a reliable and valid instrument for assessing fear of vaccination in the Polish population. The results also clarify the role of item 5, and provide evidence for strict sex invariance, offering a robust tool for research and intervention planning.