Incidence of loss of ability to walk 400 meters in a functionally limited older population.
OBJECTIVE
To assess the incidence of and factors related to nondisabled but functionally limited older adults aged 75 to 85 years losing the ability to walk 400 m.


METHODS
Observational study with average follow-up of 21 months.


METHODS
Community.


METHODS
At baseline, 101 persons with objective signs of functional limitations and intact cognitive function agreed to participate in the study. Of these, 81 were able to walk 400 m at baseline, and 62 participated in the follow-up examination.


METHODS
Mobility disability was defined as an inability to complete a 400-m walk test. At baseline, eligible participants (n=81) had the ability to walk 400 m, scored between 4 and 9 on the Short Physical Performance Battery (SPPB; range 0-12), and scored 18 or more on the Mini-Mental State Examination. Demographics, difficulty in daily activities, disease status, behavioral risk factors, and muscle strength were assessed at baseline and follow-up.


RESULTS
Of 62 persons at follow-up, 21 (33.9%) developed incident mobility disability. The strongest predictors of loss of mobility were the time to complete the 400-m walk at baseline (odds ratio (OR)=1.6 per 1-minute difference, 95% confidence interval (CI)=1.04-2.45), and decline in SPPB score over the follow-up (OR=1.4 per 1-point difference, 95% CI=1.01-1.92).


CONCLUSIONS
Older persons with functional limitations have a high rate of loss of ability to walk 400 m. The 400-m walk test is a highly relevant, discrete outcome that is an ideal target for testing preventive interventions in vulnerable older populations.
Chang
Milan
M
Laboratory of Epidemiology, Demography and Biometry, National Institute on Aging, National Institutes of Health, Bethesda, Maryland 20892, USA. changmi@hjarta.is <changmi@hjarta.is>
Cohen-Mansfield
Jiska
J
Ferrucci
Luigi
L
Leveille
Suzanne
S
Volpato
Stefano
S
de Rekeneire
Nathalie
N
Guralnik
Jack M
JM
D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D004185:Disability Evaluation; D006233:Persons with Disabilities / Q000706:statistics & numerical data*; D005260:Female; D005500:Follow-Up Studies; D016330:Frail Elderly / Q000706:statistics & numerical data*; D006801:Humans; D016015:Logistic Models; D008297:Male; D008396:Maryland; D015999:Multivariate Analysis; D012307:Risk Factors; D016138:Walking