Validity of Thai Delirium Rating Scale 6 Items Version

Abstract

The Thai Delirium Rating Scale (TDRS) 10 item is a valid diagnostic scale for delirium but has some limitations such as low internal consistency of item 2,3,4 and 9, difficulty in assessing derealization or depersonalization symptoms, especially for general practitioners and difficulty in calculating a total score for grading the severity of delirium. TDRS 6 item version has been reanalysed for its validity. The TDRS 10 item were reduced to 6 items and administered to a sample of 85 psychiatric patients to test its reliability and validity. The TDRS 6 item version can discriminate delirium from other psychiatric disease at a cut-off point >10 and has a greater validity and internal consistency than the TDRS 10 item. Cronbach's alpha coefficients of the TDRS 6 item version were nearly the same as TDRS 10 item. The Thai Delirium Rating Scale 6 item version should be used as a brief, feasible and valid instrument to diagnose delirium instead of the Thai Delirium Rating Scale 10 item version.