Abstract
Background: The 4-metre gait speed (4MGS) is a surrogate marker of physical performance and frailty. In community-dwelling older adults, slow 4MGS (<0.8ms−1) is a consistent predictor of adverse outcomes, including death. The aim of the study was to evaluate the association of the 4MGS with survival in stable patients with COPD, and to compare the prognostic ability of the 4MGS with other established predictors of mortality (FEV1,ADO,iBODE) in COPD.
Methods: 4MGS was measured in 402 patients with stable COPD. Data on vital status were obtained at 3 years.
Results: Baseline characteristics:mean age 69, FEV148%pred, 57% male. Mean (SD) 4MGS was 0.90(0.25) ms−1. Slow gait speed (≤0.80ms−1) was associated with increased risk of mortality with a hazard ratio (HR 95%CI) of 2.10 (1.25-3.53); p=0.005 (Fig 1). Each 0.1ms−1 decline in gait speed resulted in higher risk of death at 3 years (HR 1.13 (1.12-1.25);p=0.025). Multivariate analysis confirmed that 4MGS ≤0.80ms−1was an independent risk factor for all-cause death at 3 years (adjusted HR 1.78 (1.04-3.02);p=0.034). Gait speed as a single item was better than FEV1% predicted in predicting death (c-statistic 0.605 vs. 0.566). A multivariable model incorporating 4MGS, age, GOLD stage and COTE comorbidity index was a better predictor of mortality than ADO or iBODE (c-statistic 0.702 vs. 0.635 and 0.605).
Conclusion: The 4MGS, a surrogate marker of physical performance and frailty, independently predicts mortality in stable COPD.
- Copyright ©ERS 2015
