The Chinese version of the brief pain inventory-Facial (BPI-F) among different populations: Factor structure and measurement invariance

Objective: This study aimed to translate and adapt the Brief Pain Inventory-Facial (BPI-F) into Chinese, proposing a validated Chinese version for clinical application.Methods: To evaluate the applicability of Chinese BPI-F, this study included two groups: clinical sample (406 patients with OFP) and non-clinical sample (514 college students without OFP medical history). Content validity was improved through patient interviews. Cronbach's alpha was used to evaluate the reliability of BPI-F in both groups. The best-fit factor structure was tested on clinical sample via exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). Convergent and discriminant validity of BPI-F was evaluated by Spearman's coefficient. Serial CFA was used to assess measurement invariance between the two groups.Results: Content validity and reliability of BPI-F were verified. EFA results support a two-factor structure, interference with general activities (1-7 items) and face-specific pain interference (8-14 items). CFA results demonstrated this two-factor structure is appropriate for different populations. Spearman results showed that BPI-F had good convergent and discriminant validity. Full measurement invariance is observed across the two groups. Conclusion: The Chinese BPI-F, with two-factor structure (interference with general / orofacial functions), enables accurate assessment of functional interference caused by OFP. BPI-F has the same significance in different clinical populations, which expands its application.Clinical significance: This manuscript proposed the Chinese version of the BPI-F and examined its psychometric characteristics for the first time. This validated scale provides a favorable instrument for aiding individual diagnosis and treatment for OFP patients in China.