A Tunisian version of the Confusion Assessment Method for the intensive care unit (CAM-ICU): translation and validation

Abstract

Background. Delirium is common in critically ill patients and it is associated with poor outcomes. In Tunisia, however, it is still underdiagnosed as there is no validated screening tool. The aim of this study was to translate and to validate a Tunisian version of the CAM-ICU. Methods. For the validation and inter-rater reliability assessment of the Tunisian CAM-ICU, two trained intensivists independently evaluated delirium in the patients admitted to the ICU between October 2017 and June 2018. All the patients consecutively admitted to the ICU for more than 24 hours and having a Richmond Agitation-Sedation Scale greater than or equal to “-3” were assessed for delirium excluding those with stroke, dementia, psychosis or persistent coma. The results were compared with the reference evaluation carried out by a psychiatrist using the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-V) criteria. The inter-rater reliability was calculated using the kappa (κ) statistic. The CAM-ICU concurrent validity was assessed using Cronbach’s α coefficient, sensitivity, specificity as well as positive and negative predictive values (PPV and NPV, respectively) for the two Tunisian CAM-ICU raters. Results. The study involved 137 patients [median (IQR) age: 60 [49-68] years, male sex (n=102), invasive mechanical ventilation (n=49)]. Using the DSM-V criteria evaluations, 46 patients were diagnosed with delirium. When applying the Tunisian version of the CAM-ICU, 38(27.7%) patients were diagnosed with delirium for the first rater and 45(32.6%) patients for the second one. The Tunisian CAM-ICU showed a very-high inter-rater reliability for both intensivists (κ = 0.844, p<0.001). Using the DSM-V rater as the reference standard, the sensitivity of the two intensivists’ evaluations was 80.4 vs. 95.7%. Specificity was 98.9% for both. The Cronbach’s α of the first and second raters’ evaluations using the Tunisian version of the CAM-ICU were 0.886 and 0.887, respectively. Conclusions. The Tunisian version of the CAM-ICU showed almost perfect validity and reliability in detecting delirium in critically ill patients. It could therefore be used in Tunisian ICUs or where Tunisian translators are available following appropriate training. Trial registration. Not applicable.