We are greatly honoured by the interest shown by M. Cesari and S. Scarlata in our recent publications on the 4-m gait speed (4MGS) in patients with chronic obstructive pulmonary disease (COPD) [1, 2]. We strongly agree with their view that the 4MGS has value as a “vital sign”, a “marker of global well-being” and reflects biological (rather than chronological) age. Gait speed has been shown to be a strong and consistent risk factor for adverse outcomes including disability, nursing home admission, falls and mortality in community dwelling older persons [3, 4]. The intention of our studies was to draw the attention of the respiratory fraternity to the 4MGS, as we believe that the 4MGS may have a future role in stratifying patients with COPD. Although forced expiratory volume in 1 s is the most commonly used surrogate marker of disease severity, it does not reflect extrapulmonary manifestations of COPD [5]. We believe that the 4MGS provides additional information to the clinician and, given its simplicity, could be implemented widely in most clinical settings [6]. As a leading authority, M. Cesari will be aware that the 4MGS is already used to screen for sarcopenia and frailty in older adults [7, 8].
Publication information
Kon SS, Canavan JL, Nolan CM, Clark AL, Jones SE, Cullinan P, Polkey MI, Man WD. What the 4-metre gait speed measures and why it cannot replace functional capacity tests. Eur Respir J. 2014 Jun;43(6):1820-2