Cultural Validation of the Chinese Central Sensitization Inventory in Patients with Chronic Pain and Its Predictive Ability of Comorbid Central Sensitivity Syndromes

Background: Central sensitization (CS) is frequently reported in chronic pain, and the central sensitization inventory (CSI) is popularly used to assess CS. However, a validated Chinese CSI is lacking and its predictive ability for the comorbidity of central sensitivity syndromes (CSSs) remains unclear. Hence, this study aimed to generate the Chinese CSI (CSI-C) with cultural adaptation and examine its psychometric properties.

Methods: The CSI-C was formulated through forward and backward translation, panel review and piloting and then validated among patients with chronic pain (n = 235). Its internal consistency, test-retest reliability, and concurrent validity were measured. An exploratory factor analysis (EFA) was performed for the construct validity. Receiver operating characteristic (ROC) analysis was employed to determine the discriminative ability in the presence of comorbidity of CSSs.

Results: About 70% of the participants in the study experienced at least mild CS symptoms. CSI-C demonstrates a high internal consistency (Cronbach's alpha = 0.896) and excellent test-retest reliability (ICC = 0.932). CSI-C scoring was significantly correlated with pain intensity (r = 0.188), EQ-5D index (r = -0.375), anxiety (r=0.525), and depression (r = 0.467). The EFA generated a 5-factor model, including physical symptoms, emotional distress, hypersensitivity syndromes and so on. An CSI cutoff of 42 had a sensitivity of 71.4% and a specificity of 70% for identifying chronic pain patients with ≥2 CSSs.

Conclusion: The CS manifestations are prevalent in those with persistent pain. CSI-C is a reliable and valid instrument for measuring CS. A CSI score ≥42 may predict the comorbidity of 2 or above CSSs in patients with chronic pain.