Gait Speed Linked to Survival in Older Adults

Gait Speed Linked to Survival in Older Adults

Laurie Barclay, MD

 

January 4, 2011 — Gait speed is associated with survival in older adults, according to the results of a pooled analysis reported in the January 5 issue of the Journal of the American Medical Association.

"Survival estimates help individualize goals of care for geriatric patients, but life tables fail to account for the great variability in survival," write Stephanie Studenski, MD, MPH, from the Department of Medicine, Division of Geriatric Medicine, School of Medicine at the University of Pittsburgh in Pennsylvania, and colleagues. "Physical performance measures, such as gait speed, might help account for variability, allowing clinicians to make more individualized estimates."

The goal of the study was to examine the association between gait speed and survival, using a pooled analysis of 9 cohort studies with data collected between 1986 and 2000. Individual data, including baseline gait speed data, were available for 34,485 community-dwelling older adults at least 65 years old who were followed up for 6 to 21 years. Mean age was 73.5 ± 5.9 years, mean gait speed was 0.92 ± 0.27 meters per second, 59.6% were women, and 79.8% were white.

Overall 5-year survival rate was 84.8% (95% confidence interval [CI], 79.6% - 88.8%), and 10-year survival rate was 59.7% (95% CI, 46.5% - 70.6%), based on a total of 17,528 deaths. In all studies, gait speed was associated with survival, with a pooled hazard ratio of 0.88 per 0.1 meters per second (95% CI, 0.87 - 0.90; P < .001). Across the full range of gait speeds, survival rate increased, with significant increments per 0.1 meters per second.

In men aged 75 years, predicted 10-year survival rate across the range of gait speeds ranged from 19% to 87%. For women, the corresponding range was 35% to 91%.

"Predicted survival based on age, sex, and gait speed was as accurate as predicted based on age, sex, use of mobility aids, and self-reported function or as age, sex, chronic conditions, smoking history, blood pressure, body mass index, and hospitalization," the study authors write. "In this pooled analysis of individual data from 9 selected cohorts, gait speed was associated with survival in older adults."

Limitations of this study include those inherent in observational research, such as inability to establish causal relationships and healthy volunteer bias. Only 1 of the 9 pooled studies was based in clinical practice.

In an accompanying editorial comment, Matteo Cesari, MD, PhD, from Area di Geriatria, Università Campus Bio-Medico in Rome, Italy, suggests that this study "paves the way to a broader adoption of gait speed assessment."

"Because no evidence definitively supports the hypothesis that gait speed improvements are associated with better health-related outcomes, gait speed should not be considered as a primary target for interventions at this time," Dr. Cesari writes. "It represents a global marker of health status, and an optimal secondary and complementary outcome to support research findings, clinical decisions, or both aimed at modifying more pragmatic end points.... Future research will be needed to determine whether gait speed has the potential to change the way in which a patient is defined as geriatric."

The Intramural Research Program, National Institute on Aging, National Institutes of Health, supported this analysis. Some of the study authors have disclosed various financial relationships with Merck, Novartis, GTX, Hazzart Text McGraw Hill, and/or Amgen. Dr. Cesari has disclosed no relevant financial relationships.

JAMA. 2011;305:50-58, 93-94