The combined effect of visual impairment and cognitive impairment on disability in older people.
OBJECTIVE
To determine the risk of disability in individuals with coexisting visual and cognitive impairment and to compare the magnitude of risk associated with visual impairment, cognitive impairment, or the multimorbidity.


METHODS
Prospective cohort.


METHODS
North Carolina.


METHODS
Three thousand eight hundred seventy-eight participants in the North Carolina Established Populations for the Epidemiologic Studies of the Elderly with nonmissing visual status, cognitive status, and disability status data at baseline


METHODS
Short Portable Mental Status Questionnaire (cognitive impairment defined as > or =4 errors), self reported visual acuity (visual impairment defined as inability to see well enough to recognize a friend across the street or to read newspaper print), demographic and health-related variables, disability status (activities of daily living (ADLs), instrumental activities of daily living (IADLs), mobility), death, and time to nursing home placement.


RESULTS
Participants with coexisting visual and cognitive impairment were at greater risk of IADL disability (odds ratio (OR)=6.50, 95% confidence interval (CI)=4.34-9.75), mobility disability (OR=4.04, 95% CI=2.49-6.54), ADL disability (OR=2.84, 95% CI=1.87-4.32), and incident ADL disability (OR=3.66, 95%, CI=2.36-5.65). In each case, the estimated OR associated with the multimorbidity was greater than the estimated OR associated with visual or cognitive impairment alone, a pattern that was not observed for other adverse outcomes assessed. No significant interactions were observed between cognitive impairment and visual impairment as predictors of disability status.


CONCLUSIONS
Individuals with coexisting visual impairment and cognitive impairment are at high risk of disability, with each condition contributing additively to disability risk. Further study is needed to improve functional trajectories in patients with this prevalent multimorbidity. When visual or cognitive impairment is present, efforts to maximize the other function may be beneficial.
Whitson
Heather E
HE
Department of Medicine, Division of Geriatrics, Duke University Medical Center, Durham, NC 27710, USA. heather.whitson@duke.edu
Cousins
Scott W
SW
Burchett
Bruce M
BM
Hybels
Celia F
CF
Pieper
Carl F
CF
Cohen
Harvey J
HJ
D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D003072:Cognition Disorders / Q000150:complications*; D015331:Cohort Studies; D004185:Disability Evaluation; D005260:Female; D006304:Health Status; D006801:Humans; D007326:Institutionalization; D008297:Male; D018570:Risk Assessment; D012720:Severity of Illness Index; D014786:Vision Disorders / Q000150:complications*