Abstract
Chronic pain affects more than 30% of the general population. The 9-item Central Sensitization Inventory (CSI-9) is a shortened version of the CSI-25, which is a patient-reported instrument used to screen people at risk of central sensitization (CS). The aim of this study was to cross-culturally adapt and validate a Chinese version of the CSI-9. The Chinese CSI-9 was generated by translation of the original English version, back-translation, cultural adaptation, and revision using the Delphi method. The Chinese CSI-9 was administered to 235 patients with chronic pain and 55 healthy controls. Structural validity (confirmatory factor analysis), construct validity (correlations with other scales), test-retest reliability (intraclass correlation coefficient, ICC), and internal consistency (Cronbach's α) were evaluated. Confirmatory factor analysis was performed using one factor. The Chinese CSI-9 score was positively correlated with the Pain Catastrophic Scale (PCS) total score (r = 0.463), PCS subscale scores (r = 0.347-0.463), Brief Pain Inventory (BPI) mean item score (r = 0.524), BPI total score (r = 0.773), and the number of painful sites (r = 0.451). The Chinese CSI-9 had excellent test-retest reliability (ICC = 0.958) and excellent internal consistency (Cronbach's α = 0.902 in the overall sample and 0.828 in the chronic pain population). The optimal cut-off value for the Chinese CSI-9 was 18 points. The Chinese CSI-9 had excellent test-retest reliability and satisfactory structural validity and construct validity. The CSI-9 could potentially be utilized in China as a self-report questionnaire in both clinical practice and research settings.