Sickness Questionnaire: A two-factor instrument reflecting physical and mental symptoms in the Chinese context.

The Sickness Questionnaire (SicknessQ) is a 10-item inventory used to measure sickness-related symptoms. This study extended its psychometric properties in the Chinese context. A total of 992 clinical and non-clinical participants from three samples were included. Exploratory and confirmatory factor analyses indicated a 9-item two-factor structure (mental and physical symptoms) of the Chinese version of Sickness Questionnaire (SicknessQ-C). The internal consistency of the two subscales in this instrument ranged from .71 to .85. The incremental and predictive validities of SicknessQ-C demonstrated that this instrument contributed more to explaining the variance of flourishing than the measurement of negative emotion symptoms.