Clinical staging of dementia in a population survey: comparison of DSM-III-R and the Washington University Clinical Dementia Rating Scale.

In a population survey in Stockholm, 224 dementia cases were staged using two scales: the Washington University Clinical Dementia Rating Scale and DSM III-R. Both scales had to be modified by adding additional specifications and, in the case of DSM III-R, a new category of questionable dementia. After modification, the comparison of the two scales showed good agreement when all stages were analyzed (kappa = 0.60), but moderate agreement on the questionable and mild stages (kappa = 0.47). These results confirm the staging of mild dementia as the most problematic issue. Finally, the scales both showed moderate agreement with the categorized Mini-Mental State Examination (MMSE) (0-17 for severe and moderate forms; 18-23 for mild cases). Our data suggest new cut-off points for the MMSE when used as a staging scale.