Gait speed and adverse outcomes following hospitalised exacerbation of COPD

Abstract

Background: The 4-m gait speed (4MGS) test is a simple physical performance measure and surrogate marker of frailty that is associated with adverse outcomes in older adults. We aimed to assess the ability of 4MGS to predict prognosis in patients hospitalised with acute exacerbations of chronic obstructive pulmonary disease (AECOPD).

Methods: 213 participants hospitalised with AECOPD (52% male, mean age 72 years and mean forced expiratory volume in 1 s (FEV₁) 35% predicted) were enrolled. 4MGS and baseline demographics were recorded at hospital discharge. All-cause readmission and mortality were collected for 1 year after discharge and multivariable Cox proportional hazards regressions were performed. Kaplan-Meier and competing risks analyses were conducted comparing time to all-cause readmission and mortality between 4MGS quartiles.

Results: 111 participants (52%) were readmitted and 35 (16%) died during the follow-up period. 4MGS was associated with all-cause readmission, with an adjusted subdistribution hazard ratio of 0.868 (95% CI 0.797-0.945; p=0.001) per 0.1 m·s^-1 increase in gait speed, and with all-cause mortality, with an adjusted subdistribution hazard ratio of 0.747 (95% CI 0.622-0.898; p=0.002) per 0.1 m·s^-1 increase in gait speed. Readmission and mortality models incorporating 4MGS had higher discrimination than age or FEV₁ % pred alone, with areas under the receiver operator characteristic curves of 0.73 and 0.80, respectively. Kaplan-Meier and competing risks curves demonstrated that those in slower gait speed quartiles had reduced time to readmission and mortality (log-rank, both p<0.001).

Conclusions: 4MGS provides a simple means of identifying at-risk patients with COPD at hospital discharge. This provides valuable information to plan post-discharge care and support.