The Gospel Oak Study stage III: the incidence of dementia.

Of an original sample of 705 elderly (aged over 65) community residents 71% were rescreened after two years and four months using Short CARE. Thirty-one (6.7%) subjects were identified as possible new cases of dementia, implying a mean annual inception rate among the survivors of 26 per 1000. These were subjected to full clinical assessment, which yielded 10 cases of Alzheimer's disease (8 per 1000) and 5 multi-infarct dementia (4 per 1000). The remainder of the cases consisted of 6 with a dementia secondary to other causes, 1 case of mixed dementia and there was insufficient information to classify the remaining 3. Six were found not to be suffering from dementia. This yields an overall annual incidence rate for dementia among the survivors of 20 per 1000.