Online Program

Impact of visual function changes on mortality through changes in activities of daily living (ADL) and instrumental activities of daily living (IADL) among aging adults

Monday, November 4, 2013 : 1:30 p.m. - 1:50 p.m.

Sharon L. Christ, PhD, College of Health and Human Sciences, Purdue University, West Lafayette, IN
Dandan D Zheng, MS, Department of Epidemiology and Public Health, University of Miami Miller School of Medicine, Miami, FL
Byron Lam, MD, Bascom Palmer Eye Institute, University of Miami, Miami, FL
Sheila West, PhD, Johns Hopkins University, Baltimore, MD
Bonnielin K Swenor, MPH, Johns Hopkins University, Baltimore, MD
Stacey L. Tannenbaum, PhD, RD, LD/N, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL
David Lee, PhD, Epidemiology & Public Health, University of Miami, Miami, FL
Background: Repeated studies have shown that visual impairment is associated with increased risk of mortality, but the mechanism is unclear. Methods: A population-based sample in Salisbury, Maryland of 2520 white and black individuals, aged 65–84 years in 1993-1995 were re-assessed 2, 6, and 8 years later with mortality follow-up through 2009. Best-corrected ETDRS visual acuity (VA) was obtained. ADL and IADL were surveyed. VA and ADL/IADL trajectories were estimated for each respondent using OLS regression. Structural equation modeling estimated the associations among the trajectories and mortality while controlling for demographic and health covariates. Results: ADL difficulties increased by 0.16 standard deviations (SD) and IADL difficulties increased by 0.27 SD annually. In multivariable models, poorer VA at baseline was associated with worse IADLs at baseline (p < 0.001) and with worsening ADLs (p<0.01) and IADLs (p< 0.05) over time. Declining VA was associated with worsening IADL (p<0.001). For a one SD annual rate of increase in IADL the hazard of death is increased by 1.70 (p < 0.001). Visual acuity trajectories did not directly predict mortality. However, a one logmar unit annual rate of change in VA increased mortality by 77% (HR:1.77; 95% CI:1.33-2.35) through worsening IADLs. Conclusions: The impact of visual impairment and visual impairment changes in older adults on mortality operates in part through increases in IADL. Aside from preventing visual declines it may also be important to target those with visual impairment for interventions designed to reduce IADL declines.

Learning Areas:

Clinical medicine applied in public health

Learning Objectives:
Describe the association between visual acuity and activities of daily living/instrumental activities of daily living at baseline and over time. Explain how a change in visual acuity indirectly affected mortality. Discuss how utilizing structural equation modeling allowed estimation of the mediated affect of visual impairment on mortality.

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: I am a consultant for the external funding source under this grant from the National Eye Institute. I have worked under numerous federally funded grants.
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.