Alzheimer disease is an increasingly common condition in older people and the authors investigated "life expectancy after the diagnosis of Alzheimer disease" in community dwelling patients.

A prospective observational study was performed from a population of 23,000 persons age 60 years and older in the Group Health Cooperative, Seattle, Washington. "Baseline measurements included patient demographic features, Mini-Mental State Examination score, Blessed Dementia Rating Scale score, duration since reported onset of symptoms, associated symptoms, comorbid conditions, and selected signs" and recorded in a database.

The researchers found that the median survival from initial diagnosis was 4.2 years for men and 5.7 years for women with Alzheimer disease. Men had poorer survival across all age groups compared with females [and] survival was decreased in all age groups compared with the life expectancy of the U.S. population.

Of note, the researchers found that "predictors of death included a baseline Mini-Mental State Examination score of 17 or less, baseline Blessed Dementia Rating Scale score of 5.0 or greater, presence of frontal lobe release signs, presence of extrapyramidal signs, gait disturbance, history of falls, congestive heart failure, ischemic heart disease, and diabetes at baseline".

In this sample of community-dwelling elderly persons who received a diagnosis of Alzheimer disease, "atures significantly associated with reduced survival at diagnosis were increased severity of cognitive impairment, decreased functional level, history of falls, physical examination findings of frontal release signs, and abnormal gait".

Although it is not publicly known what symptoms President Reagan had prior to his diagnosis of Alzheimer's disease, his survival following this diagnosis (1994 to 2004) was much longer than the median life expectancy observed in this study. As is noted in the study, the median survival from initial diagnosis was 4.2 years for men and the late President Reagan lived twice as long as that. This gives strength to the known fact that good care can prolong survival in patients with debilitating medical conditions.

Reference:
Survival after initial diagnosis of Alzheimer disease, Ann Intern Med. 2004 Apr 6;140(7):501-9