Development and validation of the Thai version of the 4 ‘A’s Test for delirium screening in hospitalized elderly patients with acute medical illnesses

BACKGROUND: The English version of the 4 ‘A’s Test (4AT) is a rapid screening tool for delirium with a high sensitivity and specificity among hospitalized elderly patients. OBJECTIVE: To develop the Thai version of the 4AT (4AT-T) and assess its validity. SUBJECTS AND SETTING: A total of 97 elderly patients aged 60 years or above who were admitted to the general medical wards were included. METHODS: Both authors independently translated the English version of the 4AT into Thai and thereafter developed a single reconciled forward translation by consensus. Back translation was performed by a bilingual native English speaker and it was then reviewed to ensure its agreement with the original one. After 24 hours of admission, subjects were enrolled and clinical data collected. Definite diagnosis of delirium was made by a psychiatrist using the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, Text-Revision criteria and the 6-item Thai Delirium Rating Scale; the 4AT was then administered to participants by nurses within 30 minutes. A 4AT score ≥4 was considered positive for delirium screening. The optimal cut-off point of the 4AT-T was identified by Youden’s index. RESULTS: In all, 24 out of 97 participants met the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, Text-Revision criteria for delirium. At a cut-off score of 4 or greater, the 4AT-T exhibited satisfactory diagnostic performance with a sensitivity of 83.3% (95% confidence interval (CI): 62.6%–95.3%) and specificity of 86.3% (95% CI: 76.3%–93.2%). The area under the receiver operating characteristic curve was 0.92. The specified score provided maximal Youden’s index, suggesting an optimal criterion value for delirium screening. CONCLUSION: The 4AT-T is a valid delirium-screening instrument for hospitalized elderly patients with acute medical illnesses.