Correlation of 4-meter gait speed with clinical indicators of chronic obstructive pulmonary disease

BackgroundMeasuring daily physical activity and exercise capacity is recommended in the routine care of patients with chronic obstructive pulmonary disease (COPD). The 4-m gait speed (4mGS) is simple and effective in stratifying patients according to exercise performance, dyspnea, health status, and prognosis. We assessed the reliability of the 4mGS as a clinical marker by examining its association with established clinical indicators among hospitalized patients with COPD.MethodsThis retrospective study included 78 patients hospitalized with COPD (mean age: 76.3 ± 0.9 years; males, n = 69) between January 2016 and June 2018 who were assessed using the 4mGS and divided into slow (<0.8 m/s) and normal (≥0.8 m/s) 4mGS groups. Clinical characteristics were compared, including death during the observation period, time to first exacerbation, and long-term oxygen therapy requirement.ResultsThere were strong relationships between 4mGS performance, the 6-min walk test (R = 0.70; p < 0.0001), and the modified Medical Research Council dyspnea scale (R = 0.68; p < 0.0001) among the 78 patients. The slow 4mGS group had a higher frequency of death during the observation period (p = 0.0095) and a greater requirement for long-term oxygen therapy (p = 0.0063). The 4mGS correlated with inspiratory capacity (IC) and IC/total lung capacity ratios, which are respiratory failure indicators.ConclusionsThe 4mGS is a simple and easy method of assessing the physical condition as well as estimating the prognosis of patients with COPD, and may serve as a useful marker in home medical treatment or clinical settings.