Brief screening tests versus clinical staging in senile dementia of the Alzheimer type.

Several brief screening tests of cognitive function were compared with a reliable and valid global rating of the presence and severity of senile dementia of the Alzheimer type, the Washington University Clinical Dementia Rating (CDR). The six-item Short Blessed Test, the Short Portable Mental Status Questionnaire, the 26-item Blessed Information-Memory-Concentration Test, the Blessed Dementia Scale, and the Blessed Dementia Scale-Cognitive were able to discern both the presence of dementia and its severity. The six-item Short Blessed Test is preferred as a screening test because of its brevity, administration to the subject only, inclusion of a learning task, reliability, and neuropathologic validity. Evidence is presented for the convergent validity of the Initial Subject Protocol, used to derive the Clinical Dementia Rating.