Gait speed and survival in older adults

Abstract

Context: Survival estimates help individualize goals of care for geriatric patients, but life tables fail to account for the great variability in survival. Physical performance measures, such as gait speed, might help account for variability, allowing clinicians to make more individualized estimates.

Objective: To evaluate the relationship between gait speed and survival.

Design, setting, and participants: Pooled analysis of 9 cohort studies (collected between 1986 and 2000), using individual data from 34,485 community-dwelling older adults aged 65 years or older with baseline gait speed data, followed up for 6 to 21 years. Participants were a mean (SD) age of 73.5 (5.9) years; 59.6%, women; and 79.8%, white; and had a mean (SD) gait speed of 0.92 (0.27) m/s.

Main outcome measures: Survival rates and life expectancy.

Results: There were 17,528 deaths; the overall 5-year survival rate was 84.8% (confidence interval [CI], 79.6%-88.8%) and 10-year survival rate was 59.7% (95% CI, 46.5%-70.6%). Gait speed was associated with survival in all studies (pooled hazard ratio per 0.1 m/s, 0.88; 95% CI, 0.87-0.90; P < .001). Survival increased across the full range of gait speeds, with significant increments per 0.1 m/s. At age 75, predicted 10-year survival across the range of gait speeds ranged from 19% to 87% in men and from 35% to 91% in women. 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.

Conclusion: In this pooled analysis of individual data from 9 selected cohorts, gait speed was associated with survival in older adults.

Figures

Figure 1

Age-Adjusted Hazard Ratio for Death per 0.1-m/s Higher Gait Speed The size of the data markers is proportional to the square root of the number of participants. The error bars indicate 95% confidence intervals. The Q statistic for heterogeneity is 45.2 (P<.001; I2, 82.3). Pooled using random effects and shared frailty models.

Figure 2

Predicted Median Life Expectancy by Age and Gait Speed A PDF of enlarged graphs is available at http://www.jama.com.