Correlations Between Gait Speed, 6-Minute Walk Distance, Physical Activity, and Self-Efficacy in Patients With Severe Chronic Lung Disease

Abstract

BACKGROUND Four-meter gait speed (4MGS) has been associated with functional capacity and overall mortality in elderly patients, and may easily be translated to daily practice. We evaluated the association of 4MGS with meaningful outcomes. METHODS In 70 subjects we conducted the 4MGS, 6-min walk test (6MWT), objectively measured physical activity, and assessed dyspnea, quality of life, and self-efficacy for walking and routine physical activity. 4MGS was measured in 3 separate time epochs during the 6MWT, to explore 4MGS variability. RESULTS Diagnoses included COPD (51.4%), interstitial lung disease (38.6%), and other pulmonary conditions (10%). The mean ± SD values were: 4MGS 0.85 ± 0.21 m/s, 6-min walk distance (6MWD) 305 ± 115 m, and physical activity level 1.28 ± 0.17, which is consistent with severe physical inactivity. The gait speeds within the time epochs 1–2, 3–4, and 5–6 min during the 6MWT were not significantly different: 1.01 ± 0.29 m/s, 0.98 ± 0.31 m/s, and 1.00 ± 0.31 m/s, respectively. 4MGS had a significant correlation with 6MWD (r = 0.70, P < .001). 6MWD was the dominant variable for predicting 4MGS. Other significant predictors of 4MGS included dyspnea, self-efficacy, quality of life, and objectively measured physical activity. CONCLUSIONS 4MGS is significantly and independently associated with 6MWD, and may serve as a reasonable simple surrogate for 6MWD in subjects with chronic lung disease. Gait speed was remarkably stable throughout the 6MWT, which supports the validity of an abbreviated walk test such as 4MGS.

Hypovitaminosis D is associated with a reduction in upper and lower limb muscle strength and physical performance in post-menopausal women: a retrospective study

“…Our results also showed a statistically significant difference between groups regarding physical performance as assessed by SPPB (p \ 0.001) and 4MGS (p = 0.002). We performed the 4MGS evaluation in agreement with DePew et al that consider gait speed as a potential ''vital sign'' to be recorded in any medical assessment and an objective measure of the whole organism functioning [27]. The association between vitamin D and appendicular muscle functioning might be explained by the linkage between 1,25(OH) 2 D 3 , active form of vitamin D, and VDR [28], leading to increased protein synthesis and muscle cell growth [15].…”

Determinants of Gait Speed in COPD

“…Th e sample size calculation was based on the literature, with the expected correlation ( r ) between 6MWT and gait speed assumed to be 0.7 14 and the correlation between physical activity level and gait speed assumed to be 0.3. 29 We selected the lowest correlation in the sample size calculation. Determined with a probability of type I error ( a ) of 0.05, power (1 2 b ) of 0.9, and correlation of 0.3, the calculated sample size was 113, and considering a possible 15% dropout rate, the fi nal sample size was 130.…”

Measuring Gait Speed in the Out-Patient Clinic: Methodology and Feasibility

“…Recent studies have shown a link between gait speed and exercise capacity for patients with COPD. 12,13 However, those studies did not evaluate the several commonly described gait speed protocols and have not established the effect of distance walked, pace, or timing methods on the reliability and reproducibility of gait speed results in patients with COPD. Prior studies using fast pace 14,15 have not investigated the commonly used distances (4 and 10 meters) or the possible timing systems.…”