The gender differences in the association between fear of pain and dental anxiety using the Japanese version of the Fear of Pain questionnaire-III: a cross-sectional study

Background The fear of pain is closely linked with chronic pain and the resultant impairment of daily life. It has been reported to have a correlation with dental anxiety, making its assessment crucial in dental practice. The present study aimed to develop a Japanese version of the Fear of Pain Questionnaire-III (FPQ-III), an international rating scale, to evaluate psychological characteristics and investigate its association with dental anxiety and gender differences. Methods After forward and backward translation and review, the Japanese version of the FPQ-III was administered to 400 internet monitors, and 100 of them were re-evaluated after a month. Convergent validity was assessed in relation to catastrophic thoughts of dental anxiety and pain, while discriminant validity was evaluated concerning the correlations between anxiety and depression. Confirmatory factor analysis was used to examine the factorial validity of the FPQ-III and a shortened version of the FPQ-9. Item response theory was applied to estimate the discriminative power of each item and draw a test information curve. Structural equation modeling was used to investigate the relationship between pain anxiety and dental anxiety and the gender differences in the model. Results Data from 400 participants (200 women [50.0%, mean 44.9 ± 14.5 years]) were analyzed. Total scores on the FPQ-III showed good internal validity, intra-examiner reliability, and discriminant validity, indicating convergent validity. Confirmatory factor analysis results supported a three-factor structure, and the FPQ-9 showed a good fit. Discrimination was high, except for two items related to severe pain. Test information curves demonstrated that the FPQ-III and FPQ-9 were more accurate for latent characteristic values between -2 SD and +2 SD. Anxiety about medical pain fully mediated the relationship between fears of minor pain and dental anxiety. No gender differences were observed in this construct, and the factor means for anxiety about severe pain were significantly higher for women than for men. Conclusion The Japanese versions of the FPQ-III and FPQ-9 demonstrated high reliability and validity for measuring the Fear of Pain in this target population, with high accuracy for a wide range of latent characteristics. The fear of pain was deemed an endogenous factor that was linked to dental anxiety and common to both men and women.