Does Cognitive Impairment Increase the Risk for Death in Older Adults? FREE

Approximately 4 to 5 million people in the United States have dementia, and that number is expected to increase with the aging of the population. Cognitive impairment is a condition that affects memory and thinking. It may be classified as dementia when it is severe enough to interfere with normal daily activities or as mild cognitive impairment when it affects attention, language, judgment, memory, reading, or writing but does not severely impair activities of daily living.

Prior studies have associated cognitive impairment with an increased risk for death, but most focused on patients from Alzheimer disease centers or other research centers. These patients often are younger, have fewer additional medical conditions, and have more advanced dementia than patients seen in general practice.

To find out whether cognitive impairment is independently associated with increased mortality in primary care patients who are at least 60 years of age.

3957 people 60 to 102 years of age who visited an urban public hospital or a community health center or clinic in Indianapolis, Indiana, for a scheduled primary care appointment between 1991 and 1993.

Clinicians screened the patients for cognitive impairment by using a 10-question mental status questionnaire. On the basis of the number of errors patients made on this test, they were categorized as having no, mild, or moderate to severe cognitive impairment. The authors then gathered data on study patients who died through 31 December 2006. They assumed that patients had survived if they received no information about their death.

At screening, 3157 patients had no cognitive impairment, 533 had mild impairment, and 267 had moderate to severe impairment. During follow-up, 57% of patients with no impairment died, compared with 68% of those with mild impairment and 79% of those with moderate to severe impairment. Median survival time was 138 months for patients with no impairment, 106 months for those with mild impairment, and 63 months for those with moderate to severe impairment.

Patients were assessed only at enrollment, and changes in cognition, function, and comorbid conditions were not tracked over time. Because the patients came from a single safety-net health system and had low educational and socioeconomic attainment, the findings may not apply to other populations.

Both mild and moderate to severe cognitive impairment may increase risk for mortality.