Cognitive Test Performance in Relation to Health and Function in 12 European Countries: The SHARE Study.
BACKGROUND
Even subtle impairments on cognitive test scores can be associated with future cognitive decline and dementia. We assayed the relationships between test score impairment and adverse outcomes.


METHODS
Secondary analyses were performed on data from non-institutionalized participants, 50+ years of age (N = 30,038), from 12 countries taking part in the Survey of Health, Ageing and Retirement in Europe (SHARE) longitudinal study on aging. At baseline, participants' cognition was tested using verbal fluency, immediate recall, and delayed recall tasks.


RESULTS
Greater levels of cognitive impairment at baseline were strongly associated with future poor health outcomes and functional impairment. Controlling for age, sex and education, those with 1 (OR = 1.58, 95% CI = 1.34-1.87) or ≥ 2 (OR = 2.59, 95% CI = 2.17-3.09) impaired tests at baseline were more likely to die after an average of 40 months compared to individuals with no impairments. After selecting for participants who reported the absence of dementia initially, those with ≥ 2 cognitive impairments at baseline (OR = 3.34, 95% CI = 2.27-4.92) were more likely to report dementia at follow-up compared to those with no impairment.


CONCLUSIONS
People with impaired cognitive test scores at baseline are at greater risk to die or develop dementia within four years than their less impaired or unimpaired counterparts.
Department of Psychiatry, Dalhousie University, Halifax, NS; ; Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS; ; Department of Medicine, Division of Geriatric Medicine, QEII Health Sciences Centre, Dalhousie University, Halifax, NS, Canada.
Roxanne
R
Sterniczuk
Department of Medicine, Division of Geriatric Medicine, QEII Health Sciences Centre, Dalhousie University, Halifax, NS, Canada.
Olga
O
Theou
Department of Psychiatry, Dalhousie University, Halifax, NS; ; Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS;
Benjamin
B
Rusak
Department of Medicine, Division of Geriatric Medicine, QEII Health Sciences Centre, Dalhousie University, Halifax, NS, Canada.
Kenneth
K
Rockwood
Alzheimer’s disease; cognitive impairment; dementia; longitudinal studies; risk factors