CLINICAL DEMENTIA RATING TRAINING AND RELIABILITY IN MULTICENTER STUDIES - THE ALZHEIMERS-DISEASE COOPERATIVE STUDY EXPERIENCE

Global ratings of dementia severity are used increasingly in clinical trials of antidementia compounds. Such ratings are clinically relevant , but their reliability in multicenter settings has not been determine d. To evaluate the reliability of one global scale, the Clinical Demen tia Rating (CDR), 82 investigators of the multicenter Alzheimer's Dise ase Cooperative Study participated in a training and relibility protoc ol using videotaped assessments of subjects in various stages of Alzhe imer's disease, Following training, overall agreement of the investiga tors with ''gold standard'' CDR scores was 83%, These results indicate that the training protocol is useful for establishing good levels of agreement in staging dementia severity and that the CDR can be standar dized as a clinical global scale for multicenter studies of Alzheimer' s disease.