Validation of the Chinese Version of the Somatic Symptom Disorder-B Criteria Scale for Detecting DSM-5 Somatic Symptom Disorders: A Multicenter Study.

Objective: This study aimed to validate the Chinese version of the Somatic Symptom Disorder-B Criteria Scale (SSD-12) in an outpatient sample from Chinese general hospitals and to determine the diagnostic performance of the SSD-12 as a screening tool for somatic symptom disorder (SSD).

Methods: The Chinese version of the SSD-12 was completed by 699 outpatients from nine general hospitals during a 16-month period (2016-2018). The SSD section of the Structured Clinical Interview for DSM Disorders, Fifth Edition, Research Version, was used to determine diagnostic accuracy (criterion validity). The construct validity of the SSD-12 was evaluated by examining correlations with the Whiteley Index-7, Patient Health Questionnaire-15, Patient Health Questionnaire-9, General Anxiety Disorder-7, World Health Organization Disability Assessment Schedule, and Medical Outcome Study 12-item Short Form Health Survey (SF-12).

Results: The SSD-12 had excellent internal consistency in this sample (Cronbach α = .95). Confirmatory factor analyses replicated a three-factor structure that reflects the cognitive, affective, and behavioral aspects (Comparative Fit Index = 0.963, Tucker-Lewis Index = 0.952, root mean square error of approximation = 0.08, 90% confidence interval = 0.08-0.09), but was also consistent with a general one-factor model of the SSD-12 (Comparative Fit Index = 0.957, Tucker-Lewis Index = 0.948, root mean square error of approximation = 0.09, 90% confidence interval = 0.08-0.10). The optimal cutoff point for the Structured Clinical Interview for DSM Disorders-based diagnosis of SSD was 16 (sensitivity = 0.76, specificity = 0.80). The SSD-12 sum score was significantly associated with somatic symptom burden (Patient Health Questionnaire-15: r = 0.52, p < .001), health anxiety (Whiteley Index-7: r = 0.82, p < .001), depressive symptoms (Patient Health Questionnaire-9: r = 0.63, p < .001), general anxiety (General Anxiety Disorder-7: r = 0.64, p < .001), health-related quality of life (physical component score of SF-12: r = -0.49, p < .001; mental component score of SF-12: r = -0.61, p < .001), and health-related disabilities (World Health Organization Disability Assessment Schedule: r = 0.56, p < .001).

Conclusions: Initial assessment indicates that the Chinese version of the SSD-12 has sufficient reliability and validity to warrant further testing in both research and clinical settings.