Dementia Rating Scale psychometric study and its applicability in long term care institutions in Brazil

To evaluate the diagnostic sensitivity, specificity, and agreement of the Dementia Rating Scale with clinical diagnosis of cognitive impairment and to compare its psychometric measures with those from Mini Mental State Examination.

Eighty-six elders from a long-term care institution were invited to participate in a study, and fifty-eight agreed to participate. The global health assessment protocol applied to these elders contained Mini Mental State Examination and Dementia Rating Scale. Clinical diagnose of cognitive impairment was performed by experts using the DSM-IV criteria. Dementia Rating Scale score was correlated to the Mini Mental State Examination. Sensitivity and specificity of the Dementia Rating Scale and the Mini Mental State Examination were calculated.

Twenty-two (37.9%) elders had cognitive impairment (8.6% presented with mental cognitive impairment and 29.3% dementia). The Mini Mental State Examination and the Dementia Rating Scale classified 31% and 55.2% as presenting with cognitively impaired. Dementia Rating Scale and the Mini Mental State Examination scores presented a strong correlation. Dementia Rating Scale had a higher sensitivity than Mini Mental State Examination (86.4% versus 61.9%). Dementia Rating Scale presented lower diagnostic specificity than Mini Mental State Examination (63.9% versus 86.5%). Considering Dementia Rating Scale and Mini Mental State Examination, the diagnostic agreement between them and the clinical diagnosis was similar.

Dementia Rating Scale showed a high sensitivity to detect cognitive impairment in this population, and it could be a useful tool in these settings.