Factors affecting survival in Alzheimer's disease.

Factors affecting survival of 178 patients diagnosed using NINCDS/ADRDA criteria for Alzheimer's disease were studied. All patients were drawn from the Camberwell Health Authority Area and so were a representative sample of subjects from a clinical old age psychiatry service. The mortality rate of the sample was 3.5 times that expected after adjustment for age. Younger subjects had a higher standardized mortality ratio than older subjects. The cumulative three-year mortality of the sample was 47%. Factors shown to be associated with a reduced survival included: increasing age, longer duration of illness, male sex, presence of physical illness, poor cognitive function, observed depression and absence of misidentification syndromes. Apraxia was a stronger predictor of early death than aphasia or dysmnesia.