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RESEARCH STUDY

RESEARCH

A Longitudinal Study of the Association Between Visual Impairment and Mobility Performance in Older Adults: The Salisbury Eye Evaluation Study

AUTHOR:

Bonnielin K. Swenor, Beatriz Muñoz, And Sheila K. West

SPONSOR/INSTITUTION:

National Institute of Health; National Institute on Aging

YEAR PUBLISHED:

2013

PUBLICATION:

American Journal of Epidemiology

KEY HIGHLIGHTS:

  • Few longitudinal studies have examined how visual impairment affects mobility as people age.

  • Data from the Salisbury Eye Evaluation Study, a population-based sample of 2,520 adults aged 65 years and older, were used to investigate the longitudinal association between visual impairment and mobility.

  • Baseline, 2-year, 6-year, and 8-year visits occurred between 1993 and 2001.

  • Mobility was assessed by measuring speeds on the following 3 tasks: walking up 7 steps, walking down 7 steps, and walking 4 m. Random-effects linear regression was used to model factors affecting speed.

  • For each year of observation, speeds declined, and the visually impaired had significantly slower speeds than the non­–visually impaired on all 3 tests after accounting for other covariates (βwalking up steps = −0.08 steps/second, 95% confidence interval (CI): −0.10, −0.06; βwalking down steps = −0.11 steps/second, 95% CI: −0.14, −0.08; and βwalking 4 m = −0.08 m/second, 95% CI: −0.10, −0.06).

  • The interaction between years since baseline and visual impairment status was not significant, indicating that mobility speeds declined at a similar rate in the visually impaired and the non­–visually impaired. These results suggest that the impact of visual impairment on speed is significant but does not change as people age.