Early development and progression of dementing illness in the elderly: a general-practice based study.

In a study carried out in 21 general practices in Mannheim, Germany, a stratified random sample (N = 507) of patients over the age of 65 years was drawn from the total of nearly 4000 who were medically documented. Eighty per cent of the sample were examined, using the Hierarchic Dementia Scale to test cognitive functioning and the CAMDEX criteria to assess global clinical severity. Repeat assessment after a mean interval of 27 months showed that all new cases of clinical dementia had arisen in persons with mild deficits initially and represented one-fifth of this group. The first-assessment ratings of cognitive function proved to be strongly predictive of risks for age-corrected mortality, admission to long-term care and dependency at follow-up, as well as of further progressive cognitive decline.