Good repeatability ( for the 6MWT and ESWT ) and reproducibility ( for the 6MWT , 12-minute walk test , ISWT , ESWT , and incremental cycle ergometer test ) were reported by most studies assessing these tests , providing patients were familiarized with them beforeh and .
The 6MWT , ISWT , and particularly the ESWT were reported to be sensitive to therapeutic intervention .
Exercise tests are often used to evaluate the functional status of patients with COPD .
However , to the best of our knowledge , a comprehensive systematic comparison of these tests has not been performed .
We systematic ally review ed studies reporting the repeatability and /or reproducibility of these tests , and studies comparing their sensitivity to therapeutic intervention .
The minimal important difference of exercise tests in severe COPD
Our aim was to determine the minimal important difference ( MID ) for 6-min walk distance ( 6MWD ) and maximal cycle exercise capacity ( MCEC ) in patients with severe chronic obstructive pulmonary disease ( COPD ) . 1,218 patients enrolled in the National Emphysema Treatment Trial completed exercise tests before and after 4–6 weeks of pre-trial rehabilitation  , and 6 months after r and omisation to surgery or medical care .  The St George 's Respiratory Question naire ( domain and total scores ) and University of California San Diego Shortness  of Breath Question naire ( total score ) served as anchors for anchor-based MID estimates . In order to calculate distribution-based estimates , we used the st and ard error of measurement , Cohen 's effect size and the empirical rule effect size . Anchor-based estimates for the 6MWD were 18.9 m ( 95 % CI 18.1–20.1 m ) , 24.2 m ( 95 % CI 23.4–25.4 m ) , 24.6 m ( 95 % CI 23.4–25.7 m ) and 26.4 m ( 95 % CI 25.4–27.4 m ) , which were similar to distribution-based MID estimates of 25.7 , 26.8 and 30.6 m. For MCEC , anchor-based estimates for the MID were 2.2 W ( 95 % CI 2.0–2.4 W ) , 3.2 W ( 95 % CI 3.0–3.4 W ) , 3.2 W ( 95 % CI 3.0–3.4 W ) and 3.3 W ( 95 % CI 3.0–3.5 W ) , while distribution-based estimates were 5.3 and 5.5 W. We suggest a MID of 26±2 m for 6MWD and 4±1 W for MCEC for patients with severe COPD
Good repeatability ( for the 6MWT and ESWT ) and reproducibility ( for the 6MWT , 12-minute walk test , ISWT , ESWT , and incremental cycle ergometer test ) were reported by most studies assessing these tests , providing patients were familiarized with them beforeh and .
The 6MWT , ISWT , and particularly the ESWT were reported to be sensitive to therapeutic intervention .
Exercise tests are often used to evaluate the functional status of patients with COPD .
However , to the best of our knowledge , a comprehensive systematic comparison of these tests has not been performed .
We systematic ally review ed studies reporting the repeatability and /or reproducibility of these tests , and studies comparing their sensitivity to therapeutic intervention .