Background. We studied whether heterogeneous profiles
of cognitive function are relevant to
survival in patients with early Alzheimer's disease.
Methods. CAMCOG subscales of cognitive function were used as
predictors of survival, together
with gender in 157 consecutively referred patients with early Alzheimer's
disease. Statistical analysis
was performed with Cox proportional hazards analysis and Kaplan–Meier
survival curves. Survival
rates were compared with those in the general population.
Results. Eighty patients (51%) died during the follow-up that
extended to 5·7 years, with a median
survival of 4·4 years after entry. Only the praxis subscore was
statistically significant related to
survival (P<0·0001). Its predictive power was based
on only two items, including copying ability
for a spiral and a three-dimensional house, independent of age, sex, education,
score, dementia severity and symptom duration. Kaplan–Meier curves
for the combined score of
these items (0, 1, or 2) showed three groups with significantly different
survival rates for both men
and women. Comparison of gender specific survival rates with data from
the general population
showed that excess mortality was statistically significant (P<0·01)
higher in men (51%) than in
women (21%) after follow-up extending to 5 years.
Conclusions. A simple test of copying ability defines subgroups
of AD patients with large differences
in survival rates. This suggests that parietal lobe impairment is an important
predictor of mortality
in AD. Also, the course of AD may be more benign in women than in men.