Functional disability in dementia: A validation study of the Thai version of Disability Assessment for Dementia scale

PurposeThis study aimed to determine the validity and reliability of the Thai version of Disability Assessment for Dementia scale (DAD-T).MethodsThe DAD-T was administered to Thai caregivers, including 40 people with dementia [mean age 74.9 years, standard deviation (SD) 7.2 years] and 20 normal controls (mean age 69.6 years, SD 7.4 years). To study the convergent and divergent validity, the DAD-T was administered concurrently with the Thai version of Barthel Index of Activities of Daily Living (BI) and the Thai version of Mini Mental State Examination (TMSE).ResultsThe mean (SD) scores on the DAD-T were 95.2 (6.0) for normal controls, 59.9 (15.6) for mild dementia, and 20.6 (17.1) for moderate to severe dementia. The DAD-T had a high correlation with both the BI (r = 0.82, p < 0.001) and the TMSE (r = 0.91, p < 0.001). The DAD-T demonstrated excellent internal, consistent reliability (Cronbach's alpha 0.98) and test–retest reliability (r = 0.98, p < 0.001). Analysis of its relationship with sociodemographic factors showed that the DAD-T score was not significantly associated with gender, age, and education.ConclusionThe DAD-T was found to be a valid and reliable measure to assess functional disability in Thai people with dementia.