ABSTRACT
Background
Mobility, such as walking 1/4 mile, is a valuable but underutilized health indicator among older adults. For mobility to be successfully integrated into clinical practice and health policy, an easily assessed marker that predicts subsequent health outcomes is required.
Objective
To determine the association between mobility, defined as self-reported ability to walk 1/4 mile, and mortality, functional decline, and health care utilization and costs during the subsequent year.
Design
Analysis of longitudinal data from the 2003–2004 Medicare Current Beneficiary Survey, a nationally representative sample of Medicare beneficiaries.
Participants
Participants comprised 5895 community-dwelling adults aged 65 years or older enrolled in Medicare.
Main Measures
Mobility (self-reported ability to walk 1/4 mile), mortality, incident difficulty with activities of daily living (ADLs), total annual health care costs, and hospitalization rates.
Key Results
Among older adults, 28% reported difficulty and 17% inability to walk 1/4 mile at baseline. Compared to those without difficulty and adjusting for demographics, socioeconomic status, chronic conditions, and health behaviors, mortality was greater in those with difficulty [AOR (95% CI): 1.57 (1.10-2.24)] and inability [AOR (CI): 2.73 (1.79-4.15)]. New functional disability also occurred more frequently as self-reported ability to walk 1/4 mile declined (subsequent incident disability among those with no difficulty, difficulty, or inability to walk 1/4 mile at baseline was 11%, 29%, and 47% for instrumental ADLs, and 4%, 14%, and 23% for basic ADLs). Total annual health care costs were $2773 higher (95% CI $1443-4102) in persons with difficulty and $3919 higher (CI $1948-5890) in those who were unable. For each 100 persons, older adults reporting difficulty walking 1/4 mile at baseline experienced an additional 14 hospitalizations (95% CI 8-20), and those who were unable experienced an additional 22 hospitalizations (CI 14-30) during the follow-up period, compared to persons without walking difficulty.
Conclusions
Mobility disability, a simple self-report measure, is a powerful predictor of future health, function, and utilization independent of usual health and demographic indicators. Mobility disability may be used to target high-risk patients for care management and preventive interventions.
Similar content being viewed by others
REFERENCES
Buchner DM. One lap around the track: the standard for mobility disability? J Gerontol A Biol Sci Med Sci. 2008;63:586–7.
Hardy SE, McGurl DJ, Studenski SA, Degenholtz HB. Biopsychosocial characteristics of community-dwelling older adults with limited ability to walk 1/4 mile. J Am Geriatr Soc. 2010;58:539–44.
Fried LP, Guralnik JM. Disability in older adults: evidence regarding significance, etiology, and risk. J Am Geriatr Soc. 1997;45:92–100.
Newman AB, Simonsick EM, Naydeck BL, et al. Association of long-distance corridor walk performance with mortality, cardiovascular disease, mobility limitation, and disability. JAMA. 2006;295:2018–26.
Mor V, Murphy J, Masterson-Allen S, et al. Risk of functional decline among well elders. J Clin Epidemiol. 1989;42:895–904.
Simonsick EM, Newman AB, Visser M, et al. Mobility limitation in self-described well-functioning older adults: importance of endurance walk testing. J Gerontol A Biol Sci Med Sci. 2008;63:841–7.
Bowen ME, Gonzalez HM, Bowen ME, Gonzalez HM. Racial/ethnic differences in the relationship between the use of health care services and functional disability: the health and retirement study (1992-2004). Gerontologist. 2008;48:659–67.
Center for Medicare and Medicaid Services. Technical Documentation for the Medicare Current Beneficiary Survey. Medicare Current Beneficiary Survey Data Tables.2003.
Magaziner J, Zimmerman SI, Gruber-Baldini AL, Hebel JR, Fox KM. Proxy reporting in five areas of functional status. Comparison with self-reports and observations of performance. Am J Epidemiol. 1997;146:418–28.
Ciol MA, Hoffman JM, Dudgeon BJ, Shumway-Cook A, Yorkston KM, Chan L. Understanding the use of weights in the analysis of data from multistage surveys. Arch Phys Med Rehabil. 2006;87:299–303.
Melzer D, Lan TY, Guralnik JM, Melzer D, Lan T-Y, Guralnik JM. The predictive validity for mortality of the index of mobility-related limitation–results from the EPESE study. Age Ageing. 2003;32:619–25.
Newman AB, Boudreau RM, Naydeck BL, et al. A physiologic index of comorbidity: relationship to mortality and disability. J Gerontol A Biol Sci Med Sci. 2008;63:603–9.
Penninx BW, Nicklas BJ, Newman AB, et al. Metabolic syndrome and physical decline in older persons: results from the Health, Aging And Body Composition Study. J Gerontol A Biol Sci Med Sci. 2009;64:96–102.
Figaro MK, Kritchevsky SB, Resnick HE, et al. Diabetes, inflammation, and functional decline in older adults: findings from the Health, Aging and Body Composition (ABC) study. Diab Care. 2006;29:2039–45.
Penninx BW, Kritchevsky SB, Newman AB, et al. Inflammatory markers and incident mobility limitation in the elderly. J Am Geriatr Soc. 2004;52:1105–13.
Fragoso CA, Gahbauer EA, Van Ness PH, et al. Peak expiratory flow as a predictor of subsequent disability and death in community-living older persons. J Am Geriatr Soc. 2008;56:1014–20.
Gill TM, Allore HG, Hardy SE, Guo Z. The dynamic nature of mobility disability in older persons. J Am Geriatr Soc. 2006;54:248–54.
Kempen GI, van Heuvelen MJ, van den Brink RH, et al. Factors affecting contrasting results between self-reported and performance-based levels of physical limitation. Age Ageing. 1996;25:458–64.
Reuben DB, Seeman TE, Keeler E, et al. Refining the categorization of physical functional status: the added value of combining self-reported and performance-based measures. J Gerontol A Biol Sci Med Sci. 2004;59:1056–61.
Acknowledgments
This research was supported by the National Institute on Aging (R03AG032291) and the Pittsburgh Claude D. Pepper Older Americans Independence Center (NIA P30 AG-024827). Dr. Hardy is supported by a Beeson Career Development Award (K23AG030977) from the NIA, the John A. Hartford Foundation, the Atlantic Philanthropies, and the Starr Foundation. The funders had no role in the design or conduct of the study. Portions of this work were presented at the Gerontological Society of America Annual Meeting in Atlanta, GA, on November 19, 2009.
Conflict of Interest
None disclosed.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Hardy, S.E., Kang, Y., Studenski, S.A. et al. Ability to Walk 1/4 Mile Predicts Subsequent Disability, Mortality, and Health Care Costs. J GEN INTERN MED 26, 130–135 (2011). https://doi.org/10.1007/s11606-010-1543-2
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11606-010-1543-2