RESUMEN
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.