Abstract
Background: Studies have shown that dementia and cognitive impairment can
increase mortality, but less is known about the association between subjectively perceived
cognitive deficits (subjective cognitive decline, SCD) and mortality risk.
Objective: In this study, we analyzed mortality in non-demented individuals
with SCD in a general population sample aged 75+ years.
Method: Data were derived from the Leipzig Longitudinal Study of the Aged
(LEILA75+). We used the Kaplan-Meier survival method to estimate survival times of
individuals with and without SCD and multivariable Cox proportional hazards regression to
assess the association between SCD and mortality risk, controlled for covariates.
Results: Out of 953 non-demented individuals at baseline, 117 (12.3% )
expressed SCD. Participants with SCD showed a significantly higher case-fatality rate per
1,000 person-years (114.8, 95% CI = 90.5–145.7 versus 71.7, 95% CI = 64.6–79.5) and a
significantly shorter mean survival time than those without (5.4 versus 6.9 years,
p < 0.001). The association between SCD and mortality remained
significant in the Cox analysis; SCD increased mortality risk by about 50% (adjusted
Hazard Ratio = 1.51) during the study period. Besides SCD, older age, male gender,
diabetes mellitus, stroke, and lower global cognitive functioning were also significantly
associated with increased mortality.
Conclusion: Our findings suggest an increased mortality risk in non-demented
older individuals with SCD. Even though further studies are required to analyze potential
underlying mechanisms, subjective reports on cognitive deficits may be taken seriously in
clinical practice not only for an increased risk of developing dementia and AD but also
for a broader range of possible adverse health outcomes.
