Psychometric properties of the Turkish version of Central Sensitization Inventory-9 in patients with chronic musculoskeletal pain

The aim of the study was to assess the psychometric properties of the Turkish version of Central Sensitization Inventory-9 (CSI-9) in patients with chronic musculoskeletal pain. The methodological study included 92 patients with chronic musculoskeletal pain. The original version of the CSI-9 was translated and culturally adapted into Turkish. The internal consistency and test-retest reliability were evaluated with Cronbach's alpha and the intraclass correlation coefficient (ICC), respectively. The assessment of reproducibility was conducted with the standard error of measurement (SEM) and minimal detectable difference (MDD) values. Convergent validity was explored by correlation analysis between the CSI-9 and Central Sensitization Inventory (CSI-25), Brief Pain Inventory (BPI), and European Quality of Life Survey-5 Dimensions (EQ-5D). The structural validity was assessed with factor analysis. Floor and ceiling effects were also analyzed. We found a very good internal consistency (Cronbach's alpha of 0.83) and excellent test-retest reliability (ICC of 0.96) of the Turkish CSI-9. The SEM demonstrated a range between 0.19 and 1.12, and the MDD was observed to vary from 1.17 to 1.35. The CSI-9 correlated significantly with the CSI-25 (r = 0.77, P < 0.001), the pain severity subscale of the BPI (r = 0.41 to 0.53, P < 0.001), the pain interference subscale of the BPI (r = 0.21 to 0.58, P = 0.02 to P < 0.001), the EQ-5D (r = 0.24 to 0.48, P < 0.05), and the EQ-5D visual analog scale (r = -0.41, P < 0.001). One factor was identified within the CSI-9. Our data suggest that the Turkish CSI-9 is reliable and valid outcome measure for assessing CS in patients with chronic musculoskeletal pain.