Cognitive Decline Linked to Higher Mortality Risk among Elderly, study finds
Cognitive impairment markedly increases old age mortality as found in a new study published in BMC Archives of Public Health. A 20-year prospective cohort study, based on data from the Chinese Longitudinal Healthy Longevity Survey, revealed the existence of associations between cognitive decline and negative impacts on longevity, particularly severe impairment. This study was conducted by Shuang Zhao and fellow researchers.
Epidemiological survey research study was adopted with 20-year follow up. Baseline Mini-Mental State Examination (MMSE) cognitive functions were carried out to examine changes over the time span due to variations in the status. Cox proportional hazards regression models were used to assess the relationship of cognitive impairment with mortality risk. The study also calculated the PAF of mortality because of cognitive impairment, a measure that reflects the fraction of deaths potentially avertible if cognitive decline could be managed appropriately.
Key Findings
Excess Risk of Mortality with Cognitive Impairment: Compared with subjects with normal cognitive function, those with
Mild cognitive impairment has an 11% increased mortality risk (AHR = 1.11, 95% CI 1.05–1.18).
Moderate cognitive impairment had a risk of 22% increased mortality risk (AHR = 1.22, 95% CI 1.13–1.33).
Severe cognitive impairment had a risk of 30% increased mortality risk (AHR = 1.30, 95% CI 1.19–1.42).
Rapid Cognitive Decline: Mortality risk was 24% greater among those with a two-year rapid decline in cognitive function relative to a stable status over the two years of follow-up (AHR = 1.24, 95% CI 1.10–1.39).
PAF of Mortality Due to Severe Cognitive Impairment: The population-attributable fraction of mortality due to severe cognitive impairment was 3.69% (95% CI: 2.36–5.25%), and thus considerable deaths may be attributed to decline in cognition.
Several cognitive functions were independently related to increased risk of mortality:
Naming foods (AHR = 1.12, 95% CI 1.04–1.21)
Registration (AHR = 1.18, 95% CI 1.11–1.26)
Attention and calculation (AHR = 1.13, 95% CI 1.07–1.21)
Copy figure (AHR = 1.13, 95% CI 1.06–1.20)
Delayed recall (AHR = 1.14, 95% CI 1.07–1.20)
Language (AHR = 1.14, 95% CI 1.05–1.24)
The study authors concluded that cognitive impairment is inversely associated with longevity in the elderly.Such findings point toward a pressing necessity for more aggressive efforts to recognize and control the cognitive decline process itself in aging populations to bring out better outcomes for long-term health.
Reference:
Zhao, S., Yang, H., Zhao, H. et al. Role of cognitive impairment in predicting the long-term risk of all-cause mortality: a 20-year prospective cohort study in China. Arch Public Health 83, 27 (2025). https://doi.org/10.1186/s13690-024-01489-w
