Validation of the rapid eye movement sleep behavior disorder screening questionnaire in China.

We validated the Chinese version of the rapid eye movement sleep behavior disorder (RBD) screening questionnaire (RBDSQ) and calculated its cut-off value for idiopathic or symptomatic sleep behavior disorders (iRBD or sRBD) in Chinese people. Patients with RBD (n=63) and controls (n=165) were enrolled. After all subjects had completed a structured interview, the Chinese version of the RBDSQ and the video polysomnography test, we evaluated the reliability, areas under the curves and the best cut-off values of the RBDSQ and investigated the utility of RBDSQ for iRBD and sRBD in China. We found that Cronbach's alpha was 0.769 and the test-retest reliability was 0.916. RBDSQ scores in iRBD and sRBD patients were similar and higher than those in controls. A total of five points represented the best cut-off value for detecting all RBD patients. In Parkinson's disease, a total score of six points represented the best cut-off value for detecting sRBD. There was no statistically significant difference in total RBDSQ score between iRBD and sRBD, or male and female patients. There was no significant correlation between the RBDSQ score and duration or severity of RBD symptoms. The Chinese version of the RBDSQ had high sensitivity, specificity and reliability and could be used as a tool for screening RBD patients in China.