Study objectives: REM sleep behavior disorder (RBD) is a parasomnia that is commonly associated with neurodegenerative disorders. We aimed to validate the Hong Kong version of the self-reported RBD questionnaire (RBDQ-HK) with the Korean version (RBDQ-KR) and to investigate its clinical usefulness.
Methods: One-hundred five patients with RBD and 105 age- and sex-matched controls were enrolled. Thirty were randomly selected for a retest with the questionnaire after 2 to 4 weeks without any treatment. Receiver operating characteristic curve and exploratory factor analysis were used to evaluate the scale, which had a score ranging from 0 to 100.
Results: There was no difference in mean age and sex in patients with RBD and control subjects. Patients with RBD had a significantly higher total RBDQ-KR score than the control group (P < .001). The RBDQ-KR demonstrated high sensitivity (93.3%), specificity (89.5%), positive predictive value (89.9%), and negative predictive value (93.1%). Cronbach α coefficient for internal consistency of the total score of the RBDQ-KR was 0.9, which shows high reliability. Exploratory factor analysis showed two components, dream-related and behavioral factors, consistent with the main clinical features of RBD. Based on the results, the best cutoff for the total score ranging from 0 to 100 was at 18/19 and for factor 2 ranging from 0 to 75 was at 11.
Conclusions: This study showed RBDQ-KR is a valid and reliable questionnaire for RBD symptoms and severity in Korea. It serves as an effective tool to identify patients with RBD and to facilitate future clinical and research studies.
Keywords: Korean; RBD; questionnaire; reliability; validity.
© 2017 American Academy of Sleep Medicine