Reliability and validity assessment of the Japanese version of the Confusion Assessment Method for the Intensive Care...

Delirium may lead to adverse outcomes in patients with serious conditions, but is often under-diagnosed due to inadequate screening. The Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) is an established method for assessing delirium in the ICU. The validity and reliability of the Japanese version of the CAM-ICU has not, however, been verified, and we undertook this study to verify these parameters.

CAM-ICU validity and reliability were assessed in two Japanese ICUs. Using the evaluation of the DMS-IV-TR in the psychiatrists group as the standard criteria for delirium diagnosis, we compared the evaluation of the Japanese version of the CAM-ICU between the research nurses group and the staff nurses group.

According to DSM-IV-TR criteria, the prevalence of delirium was 22.0%, and according to CAM-ICU delirium was found in 22.0% with Research Nurses and 19.5% with Staff Nurses. CAM-ICU sensitivity ratings were 83% and 78%, while their specificity ratings were 95% and 97%, respectively. The Kappa inter-rater reliability was good (κ=0.85), and Cronbach's alpha coefficient was 0.69 (95% CI: 0.57-0.79). Mean rating time for the CAM-ICU was 2.5-2.8 minutes for Research Nurses and Staff Nurses, respectively.

The Japanese version of the CAM-ICU has comparable validity and reliability as a delirium assessment tool in surgical patients in two Japanese ICUs. With training, CAM-ICU can be incorporated into daily clinical practice.