Validation of the Chinese version of the Brief Pain Inventory in patients with knee osteoarthritis

BACKGROUND: Knee osteoarthritis (KOA) primarily presents with symptoms of pain and compromised functionality. Pain is a subjective manifestation that necessitates the employment of reliable evaluation tools for practical assessment, thereby enabling the formulation of appropriate interventional strategies. The Brief Pain Inventory (BPI) is a widely utilized questionnaire for evaluating the status of chronic pain. The purpose of the present study is to translate the short form of BPI into Chinese version (BPI-CV) and conduct cross-cultural adaptation to evaluate the psychometric characteristics of BPI-CV in KOA patients. METHODS: BPI-CV was translated and cross-culturally adapted according to internationally recognized guidelines. A cohort comprising 150 patients diagnosed with KOA successfully completed the demographic questionnaire, BPI-CV, Western Ontario and McMaster University Osteoarthritis Index (WOMAC), and the EuroQoL Group's five-dimension questionnaire (EQ-5D). Internal consistency and test–retest analysis were used to evaluate the reliability. The internal consistency of the scale items was evaluated by calculating the Cronbach's α value (> 0.7). We chose to employ two scales commonly used in the evaluation of KOA patients: the disease-specific WOMAC scale and the universal EQ-5D scale. Construct validity was determined through Pearson correlation analysis, comparing BPI scores with those obtained from the WOMAC and EQ-5D scales. Exploratory factor analysis was used to structural validity. RESULTS: The BPI-CV was well accepted with no ceiling or floor effect. Cronbach's α for assessing internal consistency was 0.894. Test–retest reliability was excellent with an ICC of 0.852 (95%CI 0.785–0.905). The BPI-CV showed moderate to strong correlations with the pain dimension (r = 0.496–0.860) and the functional interference dimension (r = 0.517–0.712) of the WOMAC and the EQ-5D (r = 0.527–0.743). Three factors resulted using exploratory factor analysis: pain severity, activity interference, and emotional interference, accounting for 79.0% of the total variance. Standard error of measurement was 0.539. CONCLUSION: BPI-CV has good feasibility, reliability, and validity. It can be recommended for KOA patients in mainland China. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13018-023-04218-1.