Reliability and validity of the Hierarchic Dementia Scale.

The aim of the study was to apply a method for measuring cognitive functioning in severely demented patients. Reliability and validity of the Hierarchic Dementia Scale (HDS) were tested. Fifty patients with dementia of the Alzheimer's type (DAT), multi-infarct dementia (MID), and dementia of mixed type (MIX) were studied. The interrater reliability was satisfactory as estimated by means of a kappa coefficient. The test retest reliability was rs = .96. The concurrent validity of the HDS, as measured by the correlation between the HDS and the MMSE, was rs = .86, and between the HDS and the CDR was rs = -.71. The results indicate that HDS is a useful and valid instrument for determination of the heterogeneous cognitive deficits in severe dementia.