Psychometric properties and structural validity of traditional Chinese version of the Richards–Campbell Sleep Questionnaire in intensive care unit patients without physical restraint

Background: Sleep assessment in the intensive care unit (ICU) is difficult and often unreliable. The most commonly used questionnaire for assessing ICU sleep, the Richards–Campbell Sleep Scale (RCSQ), has not been tested for reliability and construct validity in the Mandarin–Taiwanese speaking population. Objective: The objective of this study was to test the construct validity and criterion validity of the traditional Chinese version of RCSQ (TC-RCSQ) in critically ill patients without physical restraint. Methods: We adopted a cross-sectional study design. Adults aged 20 years and above were recruited from a plastic surgery ICU of a medical center. The Cronbach's alpha was used to test internal consistency; the validity testing included content validity, criterion validity, and construct validity. Criterion validity was analysed by testing the association of TC-RCSQ with the Chinese version of Verran and Snyder-Halpern Sleep Questionnaire and sleep parameter of actigraphy using the Pearson correlation coefficient; construct validity was analysed using exploratory factor analysis. Results: A total of 100 patients were included with a mean age of 49.78 years. Internal consistency reliability suggested Cronbach's alpha of 0.93. Moderate to strong correlations of TC-RCSQ with Verran–Snyder-Halpern Sleep Questionnaire were identified (r = 0.36 to 0.80, P < 0.05). We found significant correlations of actigraphic sleep efficiency with difficulty of falling sleep, awakening times, sleep quality, and total score of the TC-RCSQ (r = 0.23, 0.23, 0.20, and 0.23, P < 0.05). One factor (named as overall sleep quality) was extracted by exploratory factor analysis with a total variance explained of 78.40 %, which had good construction validity. Conclusions: The TC-RCSQ yields satisfactory reliability and validity in critically ill patients. Actigraphic sleep efficiency may be a single index for objectively sleep assessment of sleep quality in patients without physical restraint. Both the TC-RCSQ and actigraphy can aid nurses to evaluate the sleep quality in critically ill patients without physical restraint.