Mortality in individuals with mild cognitive impairment. Results of the Leipzig Longitudinal Study of the Aged (LEILA75+)

Abstract

Objective: This study aimed to investigate whether mortality is higher for individuals suffering from Mild Cognitive Impairment (MCI).

Methods: A community sample of 1,045 dementia-free individuals aged 75 years and over was examined using neuropsychological tests over a 4.5-year period. Data were analyzed with the Cox proportional hazards model after having been adjusted for age, gender, and incident dementia.

Results: Association between MCI and mortality was examined subject to varied diagnostic criteria of MCI. We found an increased risk of death that was about 1.5 times higher for individuals with MCI when a cognitive performance of more than 1.5 standard deviation below the mean of age- and education-matched controls was required and the criterion of a cognitive complaint was excluded. Males were at about a 40% increased risk of death. Risk also increased with age by about 8% per year. Incident dementia showed a significant influence on mortality only if it became manifest by 1.5 years after the baseline measurement (follow-up 1).

Conclusion: MCI is associated with increased mortality when certain diagnostic criteria are applied.