Gait speed and adverse outcomes following hospitalised exacerbation of COPD

Abstract

Four-metre gait speed (4MGS) 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 COPD (AECOPD). 213 participants hospitalised with AECOPD (52% male, mean age and FEV1, 72 years and 35% predicted) were enrolled. 4MGS and baseline demographics were recorded at hospital discharge. All-cause readmission and mortality were collected for one year after discharge, and multivariable Cox-proportional hazards regression were performed. Kaplan-Meier and Competing risk analysis was conducted comparing time to all-cause readmission and mortality between 4MGS quartiles. 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 to 0.945; p=0.001) per 0.1m/s increase in gait speed, and with all-cause mortality with an adjusted subdistribution hazard ratio of 0.747 (95% CI: 0.622 to 0.898; p=0.002) per 0.1m/s increase in gait speed. Readmission and mortality models incorporating 4MGS had higher discrimination than age or FEV1 % predicted alone, with areas under the receiver operator characteristic curves of 0.73 and 0.80 respectively. Kaplan-Meier and Competing Risk curves demonstrated that those in slower gait speed quartiles had reduced time to readmission and mortality (log rank both p<0.001). 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.