The validity and reliability of the Arabic version of the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU): A prospective cohort study

Abstract

BackgroundAccurate diagnosis for Arabic speaking critically ill patients suffering from delirium is limited by the need for a valid/reliable translation of a standardized delirium instrument such as the Confusion Assessment Method for the ICU (CAM-ICU). ObjectiveTo determine the validity and reliability of the Arabic version of the CAM-ICU. DesignA prospective cohort study design was used to conduct the current study. SettingsData collection took place in Geriatric, Emergency and Surgical intensive care units. ParticipantsFifty-eight adult patients met the inclusion criteria and participated in the study. Among the participants 22(38%) patients were on mechanical ventilation. MethodsAfter translating the CAM-ICU into Arabic language, the Arabic CAM-ICU was administered by two well-trained critical care nurses and compared with reference standard assessments by delirium experts using the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision (DSM -IV-TR), along with assessment of severity of illness using Sequential Organ Failure Assessment (SOFA). Concurrent validity was assessed by calculating sensitivity, specificity and positive and negative predictive value (PPV and NPV) for the two Arabic CAM-ICU raters, where calculations were based on considering the DSM-IV-TR criterion as the reference standard. The convergent validity of the Arabic CAM-ICU was explored by comparing the Arabic CAM-ICU ratings and the total score of SOFA (severity of illness) and MMSE (cognitive impairment). ResultsA total of 58 ICU patients were included, of whom 27 (47%) were diagnosed with delirium during their ICU stay via DSM-IV criteria. Interrater reliability for the Arabic CAM-ICU, overall and for mechanically ventilated patients assessed using Cohen's kappa (κ) were 0.82 and 1, respectively, p < 0.001. The sensitivities (95% CI) for the two critical care nurses when using the Arabic CAM-ICU compared with the reference standard were 81% (60%–93%) and 85% (65%–95%), respectively, whereas specificity (95% CI) was 81%(62%–92%) for both nurses. High sensitivity and specificity measures were also observed across subgroups; 100% for mechanically ventilated patients, 88% (60%–98%) and 79% (49%–94%) for those aged 65 years or older and 82% (56%–95%) and 75% (43%–93%) for those with SOFA scores at or above the median value. ConclusionsThe Arabic CAM-ICU appeared to be valid and reliable tool for diagnosing delirium. Future investigations may lead to a better understanding of the prevalence, predictors, and consequences of delirium among critically ill Arabic speaking patients.