The original version of the Clinical Dementia Rating (CDR) scale correlates with other dementia rating scales, and predicts nursing home (NH) admission and death. To validate the extended components of the scale, we analyzed data from subjects participating in a community-based study of dementia. The extended CDR scale also correlated with measures of dementia severity and NH residence. 'Profound' and 'terminal' stages predicted shortened survival. The extended CDR scale should be useful in studies of the later stages of dementia.