The Japanese version of the Richards-Campbell Sleep Questionnaire: Reliability and validity assessment

Aims The purpose of this study was to determine the reliability and validity of the Japanese version of the Richards-Campbell Sleep Questionnaire as a measure of sleep among intensive care unit patients in a Japanese hospital. Design Cross-sectional survey. Methods The Richards-Campbell Sleep Questionnaire was initially translated into Japanese using the back-translation method. Validity was evaluated by determining the association between sleep efficiency, measured using simplified polysomnography, and the total score on the Japanese version of the Richards-Campbell Sleep Questionnaire. Adult non-intubated intensive care unit patients who completed the five-item visual analogue scale underwent polysomnography for one night. Reliability was tested using Cronbach's alpha coefficient. Results Thirty-three patients were included in the analysis. After excluding four patients with subsyndromal delirium, the Pearson correlation coefficient was 0.602 (p = 0.001). Cronbach's alpha coefficient was 0.911. Conclusion The Japanese version of the Richards-Campbell Sleep Questionnaire could be used as an alternative to polysomnography when assessing sleep quality in lucid intensive care unit patients.