Evaluation for delirium and cognitive function in intensive care unit: reliability and validity of the Jikei Command Following Scale in Japan

Background: We developed a novel evaluation for delirium and cognitive function named Jikei Command following Scale (JCoS). The objective of this study was to examine the reliability and validity of the JCoS. Methods: JCoS consists of 8 subitems (1, hand holding and releasing; 2, plantar dorsiflexion; 3, eye opening and closing; 4, visual pursuit; 5, mouth opening; 6, neck movement; 7, two-step command; and 8, movement sustainment). Fifty patients in the intensive care unit (ICU) participated in this study. Cronbach's alpha coefficient of JCoS total score was used for internal consistency. Intraclass correlation coefficient (ICC case 2) was used for inter-examiner reliability. The kappa coefficients for each subitem score were calculated. Concurrent validity was examined by correlation with Confusion Assessment Method for the ICU (CAM-ICU) and intensive care delirium screening checklist (ICDSC). Mini-Mental State Examination (MMSE) 2 weeks after leaving the ICU was used for predictive validity. Results: The Cronbach's alpha coefficient of the JCoS Score was 0.967. The ICC (2,1) of the JCoS Score was 0.933. The kappa coefficients of each subitem were 0.668 for 1, 0.534 for 2, 0.346 for 3, 0.721 for 4, 0.474 for 5, 0.625 for 6, 0.724 for 7, and 0.709 for 8. Correlation coefficient between JCoS and the ICDSC was -0.843, and the correlation ratio between JCoS and CAM-ICU was -0.881. Correlation coefficient between JCoS and MMSE was 0.632. Conclusions: These results suggest that JCoS has sufficient reliability and validity for evaluating about delirium and cognitive function in ICU.