The measurement of psychosis in dementia: a comparison of assessment tools.

The precise operational definition of psychosis in dementia lacks consensus, partially owing to incongruence in the various assessment tools used. This study compares assessments of psychotic symptoms in persons with dementia, specifically of hallucinations and delusions, through the 4 most frequently used assessments. Participants were 74 nursing home residents from 9 nursing homes in Israel, diagnosed with dementia. Assessment tools used included the Behavioral Pathology in Alzheimer's Disease Rating Scale (BEHAVE-AD), the Neuropsychiatric Inventory-Nursing Homes (NPI-NH), the Consortium to Establish a Registry for Alzheimer's Disease Behavior Rating Scale for Dementia (CERAD-BRSD), and the Columbia University Scale for Psychopathology in Alzheimer's Disease (CUSPAD). The highest prevalence rates of delusions were found through the CUSPAD, and the lowest through the CERAD-BRSD. Rates identified by the BEHAVE-AD were intermediate and similar to those of the NPI-NH. As for hallucinations, rates indicated by the BEHAVE-AD, the NPI-NH, and the CUSPAD were similar, with small sample-based differences, and higher than those found through the CERAD-BRSD. The CERAD-BRSD, soliciting reports of the fewest specific symptoms, detected the fewest psychotic symptoms. The CUSPAD, soliciting the most items, presented the highest prevalence rates. The BEHAVE-AD and the NPI-NH had similar rates and showed a high convergent validity.